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authorAlex Elder <aelder@sgi.com>2010-05-24 11:57:36 -0500
committerAlex Elder <aelder@sgi.com>2010-05-24 11:57:36 -0500
commit88e88374ee4958786397a57f684de6f1fc5e0242 (patch)
tree750fe86ece5d65e597223eb07c5ce7cf5b3749a0
parent7e125f7b9cbfce4101191b8076d606c517a73066 (diff)
parentccf7c23fc129e75ef60e6f59f60a485b7a056598 (diff)
downloadop-kernel-dev-88e88374ee4958786397a57f684de6f1fc5e0242.zip
op-kernel-dev-88e88374ee4958786397a57f684de6f1fc5e0242.tar.gz
Merge branch 'delayed-logging-for-2.6.35' into for-linus
-rw-r--r--Documentation/filesystems/xfs-delayed-logging-design.txt816
-rw-r--r--fs/xfs/Makefile1
-rw-r--r--fs/xfs/linux-2.6/xfs_buf.c9
-rw-r--r--fs/xfs/linux-2.6/xfs_quotaops.c1
-rw-r--r--fs/xfs/linux-2.6/xfs_super.c12
-rw-r--r--fs/xfs/linux-2.6/xfs_trace.h83
-rw-r--r--fs/xfs/quota/xfs_dquot.c6
-rw-r--r--fs/xfs/xfs_ag.h24
-rw-r--r--fs/xfs/xfs_alloc.c357
-rw-r--r--fs/xfs/xfs_alloc.h7
-rw-r--r--fs/xfs/xfs_alloc_btree.c2
-rw-r--r--fs/xfs/xfs_buf_item.c166
-rw-r--r--fs/xfs/xfs_buf_item.h18
-rw-r--r--fs/xfs/xfs_error.c2
-rw-r--r--fs/xfs/xfs_log.c120
-rw-r--r--fs/xfs/xfs_log.h14
-rw-r--r--fs/xfs/xfs_log_cil.c725
-rw-r--r--fs/xfs/xfs_log_priv.h118
-rw-r--r--fs/xfs/xfs_log_recover.c46
-rw-r--r--fs/xfs/xfs_log_recover.h2
-rw-r--r--fs/xfs/xfs_mount.h1
-rw-r--r--fs/xfs/xfs_trans.c144
-rw-r--r--fs/xfs/xfs_trans.h44
-rw-r--r--fs/xfs/xfs_trans_buf.c46
-rw-r--r--fs/xfs/xfs_trans_item.c114
-rw-r--r--fs/xfs/xfs_trans_priv.h15
-rw-r--r--fs/xfs/xfs_types.h2
27 files changed, 2382 insertions, 513 deletions
diff --git a/Documentation/filesystems/xfs-delayed-logging-design.txt b/Documentation/filesystems/xfs-delayed-logging-design.txt
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+XFS Delayed Logging Design
+--------------------------
+
+Introduction to Re-logging in XFS
+---------------------------------
+
+XFS logging is a combination of logical and physical logging. Some objects,
+such as inodes and dquots, are logged in logical format where the details
+logged are made up of the changes to in-core structures rather than on-disk
+structures. Other objects - typically buffers - have their physical changes
+logged. The reason for these differences is to reduce the amount of log space
+required for objects that are frequently logged. Some parts of inodes are more
+frequently logged than others, and inodes are typically more frequently logged
+than any other object (except maybe the superblock buffer) so keeping the
+amount of metadata logged low is of prime importance.
+
+The reason that this is such a concern is that XFS allows multiple separate
+modifications to a single object to be carried in the log at any given time.
+This allows the log to avoid needing to flush each change to disk before
+recording a new change to the object. XFS does this via a method called
+"re-logging". Conceptually, this is quite simple - all it requires is that any
+new change to the object is recorded with a *new copy* of all the existing
+changes in the new transaction that is written to the log.
+
+That is, if we have a sequence of changes A through to F, and the object was
+written to disk after change D, we would see in the log the following series
+of transactions, their contents and the log sequence number (LSN) of the
+transaction:
+
+ Transaction Contents LSN
+ A A X
+ B A+B X+n
+ C A+B+C X+n+m
+ D A+B+C+D X+n+m+o
+ <object written to disk>
+ E E Y (> X+n+m+o)
+ F E+F Yٍ+p
+
+In other words, each time an object is relogged, the new transaction contains
+the aggregation of all the previous changes currently held only in the log.
+
+This relogging technique also allows objects to be moved forward in the log so
+that an object being relogged does not prevent the tail of the log from ever
+moving forward. This can be seen in the table above by the changing
+(increasing) LSN of each subsquent transaction - the LSN is effectively a
+direct encoding of the location in the log of the transaction.
+
+This relogging is also used to implement long-running, multiple-commit
+transactions. These transaction are known as rolling transactions, and require
+a special log reservation known as a permanent transaction reservation. A
+typical example of a rolling transaction is the removal of extents from an
+inode which can only be done at a rate of two extents per transaction because
+of reservation size limitations. Hence a rolling extent removal transaction
+keeps relogging the inode and btree buffers as they get modified in each
+removal operation. This keeps them moving forward in the log as the operation
+progresses, ensuring that current operation never gets blocked by itself if the
+log wraps around.
+
+Hence it can be seen that the relogging operation is fundamental to the correct
+working of the XFS journalling subsystem. From the above description, most
+people should be able to see why the XFS metadata operations writes so much to
+the log - repeated operations to the same objects write the same changes to
+the log over and over again. Worse is the fact that objects tend to get
+dirtier as they get relogged, so each subsequent transaction is writing more
+metadata into the log.
+
+Another feature of the XFS transaction subsystem is that most transactions are
+asynchronous. That is, they don't commit to disk until either a log buffer is
+filled (a log buffer can hold multiple transactions) or a synchronous operation
+forces the log buffers holding the transactions to disk. This means that XFS is
+doing aggregation of transactions in memory - batching them, if you like - to
+minimise the impact of the log IO on transaction throughput.
+
+The limitation on asynchronous transaction throughput is the number and size of
+log buffers made available by the log manager. By default there are 8 log
+buffers available and the size of each is 32kB - the size can be increased up
+to 256kB by use of a mount option.
+
+Effectively, this gives us the maximum bound of outstanding metadata changes
+that can be made to the filesystem at any point in time - if all the log
+buffers are full and under IO, then no more transactions can be committed until
+the current batch completes. It is now common for a single current CPU core to
+be to able to issue enough transactions to keep the log buffers full and under
+IO permanently. Hence the XFS journalling subsystem can be considered to be IO
+bound.
+
+Delayed Logging: Concepts
+-------------------------
+
+The key thing to note about the asynchronous logging combined with the
+relogging technique XFS uses is that we can be relogging changed objects
+multiple times before they are committed to disk in the log buffers. If we
+return to the previous relogging example, it is entirely possible that
+transactions A through D are committed to disk in the same log buffer.
+
+That is, a single log buffer may contain multiple copies of the same object,
+but only one of those copies needs to be there - the last one "D", as it
+contains all the changes from the previous changes. In other words, we have one
+necessary copy in the log buffer, and three stale copies that are simply
+wasting space. When we are doing repeated operations on the same set of
+objects, these "stale objects" can be over 90% of the space used in the log
+buffers. It is clear that reducing the number of stale objects written to the
+log would greatly reduce the amount of metadata we write to the log, and this
+is the fundamental goal of delayed logging.
+
+From a conceptual point of view, XFS is already doing relogging in memory (where
+memory == log buffer), only it is doing it extremely inefficiently. It is using
+logical to physical formatting to do the relogging because there is no
+infrastructure to keep track of logical changes in memory prior to physically
+formatting the changes in a transaction to the log buffer. Hence we cannot avoid
+accumulating stale objects in the log buffers.
+
+Delayed logging is the name we've given to keeping and tracking transactional
+changes to objects in memory outside the log buffer infrastructure. Because of
+the relogging concept fundamental to the XFS journalling subsystem, this is
+actually relatively easy to do - all the changes to logged items are already
+tracked in the current infrastructure. The big problem is how to accumulate
+them and get them to the log in a consistent, recoverable manner.
+Describing the problems and how they have been solved is the focus of this
+document.
+
+One of the key changes that delayed logging makes to the operation of the
+journalling subsystem is that it disassociates the amount of outstanding
+metadata changes from the size and number of log buffers available. In other
+words, instead of there only being a maximum of 2MB of transaction changes not
+written to the log at any point in time, there may be a much greater amount
+being accumulated in memory. Hence the potential for loss of metadata on a
+crash is much greater than for the existing logging mechanism.
+
+It should be noted that this does not change the guarantee that log recovery
+will result in a consistent filesystem. What it does mean is that as far as the
+recovered filesystem is concerned, there may be many thousands of transactions
+that simply did not occur as a result of the crash. This makes it even more
+important that applications that care about their data use fsync() where they
+need to ensure application level data integrity is maintained.
+
+It should be noted that delayed logging is not an innovative new concept that
+warrants rigorous proofs to determine whether it is correct or not. The method
+of accumulating changes in memory for some period before writing them to the
+log is used effectively in many filesystems including ext3 and ext4. Hence
+no time is spent in this document trying to convince the reader that the
+concept is sound. Instead it is simply considered a "solved problem" and as
+such implementing it in XFS is purely an exercise in software engineering.
+
+The fundamental requirements for delayed logging in XFS are simple:
+
+ 1. Reduce the amount of metadata written to the log by at least
+ an order of magnitude.
+ 2. Supply sufficient statistics to validate Requirement #1.
+ 3. Supply sufficient new tracing infrastructure to be able to debug
+ problems with the new code.
+ 4. No on-disk format change (metadata or log format).
+ 5. Enable and disable with a mount option.
+ 6. No performance regressions for synchronous transaction workloads.
+
+Delayed Logging: Design
+-----------------------
+
+Storing Changes
+
+The problem with accumulating changes at a logical level (i.e. just using the
+existing log item dirty region tracking) is that when it comes to writing the
+changes to the log buffers, we need to ensure that the object we are formatting
+is not changing while we do this. This requires locking the object to prevent
+concurrent modification. Hence flushing the logical changes to the log would
+require us to lock every object, format them, and then unlock them again.
+
+This introduces lots of scope for deadlocks with transactions that are already
+running. For example, a transaction has object A locked and modified, but needs
+the delayed logging tracking lock to commit the transaction. However, the
+flushing thread has the delayed logging tracking lock already held, and is
+trying to get the lock on object A to flush it to the log buffer. This appears
+to be an unsolvable deadlock condition, and it was solving this problem that
+was the barrier to implementing delayed logging for so long.
+
+The solution is relatively simple - it just took a long time to recognise it.
+Put simply, the current logging code formats the changes to each item into an
+vector array that points to the changed regions in the item. The log write code
+simply copies the memory these vectors point to into the log buffer during
+transaction commit while the item is locked in the transaction. Instead of
+using the log buffer as the destination of the formatting code, we can use an
+allocated memory buffer big enough to fit the formatted vector.
+
+If we then copy the vector into the memory buffer and rewrite the vector to
+point to the memory buffer rather than the object itself, we now have a copy of
+the changes in a format that is compatible with the log buffer writing code.
+that does not require us to lock the item to access. This formatting and
+rewriting can all be done while the object is locked during transaction commit,
+resulting in a vector that is transactionally consistent and can be accessed
+without needing to lock the owning item.
+
+Hence we avoid the need to lock items when we need to flush outstanding
+asynchronous transactions to the log. The differences between the existing
+formatting method and the delayed logging formatting can be seen in the
+diagram below.
+
+Current format log vector:
+
+Object +---------------------------------------------+
+Vector 1 +----+
+Vector 2 +----+
+Vector 3 +----------+
+
+After formatting:
+
+Log Buffer +-V1-+-V2-+----V3----+
+
+Delayed logging vector:
+
+Object +---------------------------------------------+
+Vector 1 +----+
+Vector 2 +----+
+Vector 3 +----------+
+
+After formatting:
+
+Memory Buffer +-V1-+-V2-+----V3----+
+Vector 1 +----+
+Vector 2 +----+
+Vector 3 +----------+
+
+The memory buffer and associated vector need to be passed as a single object,
+but still need to be associated with the parent object so if the object is
+relogged we can replace the current memory buffer with a new memory buffer that
+contains the latest changes.
+
+The reason for keeping the vector around after we've formatted the memory
+buffer is to support splitting vectors across log buffer boundaries correctly.
+If we don't keep the vector around, we do not know where the region boundaries
+are in the item, so we'd need a new encapsulation method for regions in the log
+buffer writing (i.e. double encapsulation). This would be an on-disk format
+change and as such is not desirable. It also means we'd have to write the log
+region headers in the formatting stage, which is problematic as there is per
+region state that needs to be placed into the headers during the log write.
+
+Hence we need to keep the vector, but by attaching the memory buffer to it and
+rewriting the vector addresses to point at the memory buffer we end up with a
+self-describing object that can be passed to the log buffer write code to be
+handled in exactly the same manner as the existing log vectors are handled.
+Hence we avoid needing a new on-disk format to handle items that have been
+relogged in memory.
+
+
+Tracking Changes
+
+Now that we can record transactional changes in memory in a form that allows
+them to be used without limitations, we need to be able to track and accumulate
+them so that they can be written to the log at some later point in time. The
+log item is the natural place to store this vector and buffer, and also makes sense
+to be the object that is used to track committed objects as it will always
+exist once the object has been included in a transaction.
+
+The log item is already used to track the log items that have been written to
+the log but not yet written to disk. Such log items are considered "active"
+and as such are stored in the Active Item List (AIL) which is a LSN-ordered
+double linked list. Items are inserted into this list during log buffer IO
+completion, after which they are unpinned and can be written to disk. An object
+that is in the AIL can be relogged, which causes the object to be pinned again
+and then moved forward in the AIL when the log buffer IO completes for that
+transaction.
+
+Essentially, this shows that an item that is in the AIL can still be modified
+and relogged, so any tracking must be separate to the AIL infrastructure. As
+such, we cannot reuse the AIL list pointers for tracking committed items, nor
+can we store state in any field that is protected by the AIL lock. Hence the
+committed item tracking needs it's own locks, lists and state fields in the log
+item.
+
+Similar to the AIL, tracking of committed items is done through a new list
+called the Committed Item List (CIL). The list tracks log items that have been
+committed and have formatted memory buffers attached to them. It tracks objects
+in transaction commit order, so when an object is relogged it is removed from
+it's place in the list and re-inserted at the tail. This is entirely arbitrary
+and done to make it easy for debugging - the last items in the list are the
+ones that are most recently modified. Ordering of the CIL is not necessary for
+transactional integrity (as discussed in the next section) so the ordering is
+done for convenience/sanity of the developers.
+
+
+Delayed Logging: Checkpoints
+
+When we have a log synchronisation event, commonly known as a "log force",
+all the items in the CIL must be written into the log via the log buffers.
+We need to write these items in the order that they exist in the CIL, and they
+need to be written as an atomic transaction. The need for all the objects to be
+written as an atomic transaction comes from the requirements of relogging and
+log replay - all the changes in all the objects in a given transaction must
+either be completely replayed during log recovery, or not replayed at all. If
+a transaction is not replayed because it is not complete in the log, then
+no later transactions should be replayed, either.
+
+To fulfill this requirement, we need to write the entire CIL in a single log
+transaction. Fortunately, the XFS log code has no fixed limit on the size of a
+transaction, nor does the log replay code. The only fundamental limit is that
+the transaction cannot be larger than just under half the size of the log. The
+reason for this limit is that to find the head and tail of the log, there must
+be at least one complete transaction in the log at any given time. If a
+transaction is larger than half the log, then there is the possibility that a
+crash during the write of a such a transaction could partially overwrite the
+only complete previous transaction in the log. This will result in a recovery
+failure and an inconsistent filesystem and hence we must enforce the maximum
+size of a checkpoint to be slightly less than a half the log.
+
+Apart from this size requirement, a checkpoint transaction looks no different
+to any other transaction - it contains a transaction header, a series of
+formatted log items and a commit record at the tail. From a recovery
+perspective, the checkpoint transaction is also no different - just a lot
+bigger with a lot more items in it. The worst case effect of this is that we
+might need to tune the recovery transaction object hash size.
+
+Because the checkpoint is just another transaction and all the changes to log
+items are stored as log vectors, we can use the existing log buffer writing
+code to write the changes into the log. To do this efficiently, we need to
+minimise the time we hold the CIL locked while writing the checkpoint
+transaction. The current log write code enables us to do this easily with the
+way it separates the writing of the transaction contents (the log vectors) from
+the transaction commit record, but tracking this requires us to have a
+per-checkpoint context that travels through the log write process through to
+checkpoint completion.
+
+Hence a checkpoint has a context that tracks the state of the current
+checkpoint from initiation to checkpoint completion. A new context is initiated
+at the same time a checkpoint transaction is started. That is, when we remove
+all the current items from the CIL during a checkpoint operation, we move all
+those changes into the current checkpoint context. We then initialise a new
+context and attach that to the CIL for aggregation of new transactions.
+
+This allows us to unlock the CIL immediately after transfer of all the
+committed items and effectively allow new transactions to be issued while we
+are formatting the checkpoint into the log. It also allows concurrent
+checkpoints to be written into the log buffers in the case of log force heavy
+workloads, just like the existing transaction commit code does. This, however,
+requires that we strictly order the commit records in the log so that
+checkpoint sequence order is maintained during log replay.
+
+To ensure that we can be writing an item into a checkpoint transaction at
+the same time another transaction modifies the item and inserts the log item
+into the new CIL, then checkpoint transaction commit code cannot use log items
+to store the list of log vectors that need to be written into the transaction.
+Hence log vectors need to be able to be chained together to allow them to be
+detatched from the log items. That is, when the CIL is flushed the memory
+buffer and log vector attached to each log item needs to be attached to the
+checkpoint context so that the log item can be released. In diagrammatic form,
+the CIL would look like this before the flush:
+
+ CIL Head
+ |
+ V
+ Log Item <-> log vector 1 -> memory buffer
+ | -> vector array
+ V
+ Log Item <-> log vector 2 -> memory buffer
+ | -> vector array
+ V
+ ......
+ |
+ V
+ Log Item <-> log vector N-1 -> memory buffer
+ | -> vector array
+ V
+ Log Item <-> log vector N -> memory buffer
+ -> vector array
+
+And after the flush the CIL head is empty, and the checkpoint context log
+vector list would look like:
+
+ Checkpoint Context
+ |
+ V
+ log vector 1 -> memory buffer
+ | -> vector array
+ | -> Log Item
+ V
+ log vector 2 -> memory buffer
+ | -> vector array
+ | -> Log Item
+ V
+ ......
+ |
+ V
+ log vector N-1 -> memory buffer
+ | -> vector array
+ | -> Log Item
+ V
+ log vector N -> memory buffer
+ -> vector array
+ -> Log Item
+
+Once this transfer is done, the CIL can be unlocked and new transactions can
+start, while the checkpoint flush code works over the log vector chain to
+commit the checkpoint.
+
+Once the checkpoint is written into the log buffers, the checkpoint context is
+attached to the log buffer that the commit record was written to along with a
+completion callback. Log IO completion will call that callback, which can then
+run transaction committed processing for the log items (i.e. insert into AIL
+and unpin) in the log vector chain and then free the log vector chain and
+checkpoint context.
+
+Discussion Point: I am uncertain as to whether the log item is the most
+efficient way to track vectors, even though it seems like the natural way to do
+it. The fact that we walk the log items (in the CIL) just to chain the log
+vectors and break the link between the log item and the log vector means that
+we take a cache line hit for the log item list modification, then another for
+the log vector chaining. If we track by the log vectors, then we only need to
+break the link between the log item and the log vector, which means we should
+dirty only the log item cachelines. Normally I wouldn't be concerned about one
+vs two dirty cachelines except for the fact I've seen upwards of 80,000 log
+vectors in one checkpoint transaction. I'd guess this is a "measure and
+compare" situation that can be done after a working and reviewed implementation
+is in the dev tree....
+
+Delayed Logging: Checkpoint Sequencing
+
+One of the key aspects of the XFS transaction subsystem is that it tags
+committed transactions with the log sequence number of the transaction commit.
+This allows transactions to be issued asynchronously even though there may be
+future operations that cannot be completed until that transaction is fully
+committed to the log. In the rare case that a dependent operation occurs (e.g.
+re-using a freed metadata extent for a data extent), a special, optimised log
+force can be issued to force the dependent transaction to disk immediately.
+
+To do this, transactions need to record the LSN of the commit record of the
+transaction. This LSN comes directly from the log buffer the transaction is
+written into. While this works just fine for the existing transaction
+mechanism, it does not work for delayed logging because transactions are not
+written directly into the log buffers. Hence some other method of sequencing
+transactions is required.
+
+As discussed in the checkpoint section, delayed logging uses per-checkpoint
+contexts, and as such it is simple to assign a sequence number to each
+checkpoint. Because the switching of checkpoint contexts must be done
+atomically, it is simple to ensure that each new context has a monotonically
+increasing sequence number assigned to it without the need for an external
+atomic counter - we can just take the current context sequence number and add
+one to it for the new context.
+
+Then, instead of assigning a log buffer LSN to the transaction commit LSN
+during the commit, we can assign the current checkpoint sequence. This allows
+operations that track transactions that have not yet completed know what
+checkpoint sequence needs to be committed before they can continue. As a
+result, the code that forces the log to a specific LSN now needs to ensure that
+the log forces to a specific checkpoint.
+
+To ensure that we can do this, we need to track all the checkpoint contexts
+that are currently committing to the log. When we flush a checkpoint, the
+context gets added to a "committing" list which can be searched. When a
+checkpoint commit completes, it is removed from the committing list. Because
+the checkpoint context records the LSN of the commit record for the checkpoint,
+we can also wait on the log buffer that contains the commit record, thereby
+using the existing log force mechanisms to execute synchronous forces.
+
+It should be noted that the synchronous forces may need to be extended with
+mitigation algorithms similar to the current log buffer code to allow
+aggregation of multiple synchronous transactions if there are already
+synchronous transactions being flushed. Investigation of the performance of the
+current design is needed before making any decisions here.
+
+The main concern with log forces is to ensure that all the previous checkpoints
+are also committed to disk before the one we need to wait for. Therefore we
+need to check that all the prior contexts in the committing list are also
+complete before waiting on the one we need to complete. We do this
+synchronisation in the log force code so that we don't need to wait anywhere
+else for such serialisation - it only matters when we do a log force.
+
+The only remaining complexity is that a log force now also has to handle the
+case where the forcing sequence number is the same as the current context. That
+is, we need to flush the CIL and potentially wait for it to complete. This is a
+simple addition to the existing log forcing code to check the sequence numbers
+and push if required. Indeed, placing the current sequence checkpoint flush in
+the log force code enables the current mechanism for issuing synchronous
+transactions to remain untouched (i.e. commit an asynchronous transaction, then
+force the log at the LSN of that transaction) and so the higher level code
+behaves the same regardless of whether delayed logging is being used or not.
+
+Delayed Logging: Checkpoint Log Space Accounting
+
+The big issue for a checkpoint transaction is the log space reservation for the
+transaction. We don't know how big a checkpoint transaction is going to be
+ahead of time, nor how many log buffers it will take to write out, nor the
+number of split log vector regions are going to be used. We can track the
+amount of log space required as we add items to the commit item list, but we
+still need to reserve the space in the log for the checkpoint.
+
+A typical transaction reserves enough space in the log for the worst case space
+usage of the transaction. The reservation accounts for log record headers,
+transaction and region headers, headers for split regions, buffer tail padding,
+etc. as well as the actual space for all the changed metadata in the
+transaction. While some of this is fixed overhead, much of it is dependent on
+the size of the transaction and the number of regions being logged (the number
+of log vectors in the transaction).
+
+An example of the differences would be logging directory changes versus logging
+inode changes. If you modify lots of inode cores (e.g. chmod -R g+w *), then
+there are lots of transactions that only contain an inode core and an inode log
+format structure. That is, two vectors totaling roughly 150 bytes. If we modify
+10,000 inodes, we have about 1.5MB of metadata to write in 20,000 vectors. Each
+vector is 12 bytes, so the total to be logged is approximately 1.75MB. In
+comparison, if we are logging full directory buffers, they are typically 4KB
+each, so we in 1.5MB of directory buffers we'd have roughly 400 buffers and a
+buffer format structure for each buffer - roughly 800 vectors or 1.51MB total
+space. From this, it should be obvious that a static log space reservation is
+not particularly flexible and is difficult to select the "optimal value" for
+all workloads.
+
+Further, if we are going to use a static reservation, which bit of the entire
+reservation does it cover? We account for space used by the transaction
+reservation by tracking the space currently used by the object in the CIL and
+then calculating the increase or decrease in space used as the object is
+relogged. This allows for a checkpoint reservation to only have to account for
+log buffer metadata used such as log header records.
+
+However, even using a static reservation for just the log metadata is
+problematic. Typically log record headers use at least 16KB of log space per
+1MB of log space consumed (512 bytes per 32k) and the reservation needs to be
+large enough to handle arbitrary sized checkpoint transactions. This
+reservation needs to be made before the checkpoint is started, and we need to
+be able to reserve the space without sleeping. For a 8MB checkpoint, we need a
+reservation of around 150KB, which is a non-trivial amount of space.
+
+A static reservation needs to manipulate the log grant counters - we can take a
+permanent reservation on the space, but we still need to make sure we refresh
+the write reservation (the actual space available to the transaction) after
+every checkpoint transaction completion. Unfortunately, if this space is not
+available when required, then the regrant code will sleep waiting for it.
+
+The problem with this is that it can lead to deadlocks as we may need to commit
+checkpoints to be able to free up log space (refer back to the description of
+rolling transactions for an example of this). Hence we *must* always have
+space available in the log if we are to use static reservations, and that is
+very difficult and complex to arrange. It is possible to do, but there is a
+simpler way.
+
+The simpler way of doing this is tracking the entire log space used by the
+items in the CIL and using this to dynamically calculate the amount of log
+space required by the log metadata. If this log metadata space changes as a
+result of a transaction commit inserting a new memory buffer into the CIL, then
+the difference in space required is removed from the transaction that causes
+the change. Transactions at this level will *always* have enough space
+available in their reservation for this as they have already reserved the
+maximal amount of log metadata space they require, and such a delta reservation
+will always be less than or equal to the maximal amount in the reservation.
+
+Hence we can grow the checkpoint transaction reservation dynamically as items
+are added to the CIL and avoid the need for reserving and regranting log space
+up front. This avoids deadlocks and removes a blocking point from the
+checkpoint flush code.
+
+As mentioned early, transactions can't grow to more than half the size of the
+log. Hence as part of the reservation growing, we need to also check the size
+of the reservation against the maximum allowed transaction size. If we reach
+the maximum threshold, we need to push the CIL to the log. This is effectively
+a "background flush" and is done on demand. This is identical to
+a CIL push triggered by a log force, only that there is no waiting for the
+checkpoint commit to complete. This background push is checked and executed by
+transaction commit code.
+
+If the transaction subsystem goes idle while we still have items in the CIL,
+they will be flushed by the periodic log force issued by the xfssyncd. This log
+force will push the CIL to disk, and if the transaction subsystem stays idle,
+allow the idle log to be covered (effectively marked clean) in exactly the same
+manner that is done for the existing logging method. A discussion point is
+whether this log force needs to be done more frequently than the current rate
+which is once every 30s.
+
+
+Delayed Logging: Log Item Pinning
+
+Currently log items are pinned during transaction commit while the items are
+still locked. This happens just after the items are formatted, though it could
+be done any time before the items are unlocked. The result of this mechanism is
+that items get pinned once for every transaction that is committed to the log
+buffers. Hence items that are relogged in the log buffers will have a pin count
+for every outstanding transaction they were dirtied in. When each of these
+transactions is completed, they will unpin the item once. As a result, the item
+only becomes unpinned when all the transactions complete and there are no
+pending transactions. Thus the pinning and unpinning of a log item is symmetric
+as there is a 1:1 relationship with transaction commit and log item completion.
+
+For delayed logging, however, we have an assymetric transaction commit to
+completion relationship. Every time an object is relogged in the CIL it goes
+through the commit process without a corresponding completion being registered.
+That is, we now have a many-to-one relationship between transaction commit and
+log item completion. The result of this is that pinning and unpinning of the
+log items becomes unbalanced if we retain the "pin on transaction commit, unpin
+on transaction completion" model.
+
+To keep pin/unpin symmetry, the algorithm needs to change to a "pin on
+insertion into the CIL, unpin on checkpoint completion". In other words, the
+pinning and unpinning becomes symmetric around a checkpoint context. We have to
+pin the object the first time it is inserted into the CIL - if it is already in
+the CIL during a transaction commit, then we do not pin it again. Because there
+can be multiple outstanding checkpoint contexts, we can still see elevated pin
+counts, but as each checkpoint completes the pin count will retain the correct
+value according to it's context.
+
+Just to make matters more slightly more complex, this checkpoint level context
+for the pin count means that the pinning of an item must take place under the
+CIL commit/flush lock. If we pin the object outside this lock, we cannot
+guarantee which context the pin count is associated with. This is because of
+the fact pinning the item is dependent on whether the item is present in the
+current CIL or not. If we don't pin the CIL first before we check and pin the
+object, we have a race with CIL being flushed between the check and the pin
+(or not pinning, as the case may be). Hence we must hold the CIL flush/commit
+lock to guarantee that we pin the items correctly.
+
+Delayed Logging: Concurrent Scalability
+
+A fundamental requirement for the CIL is that accesses through transaction
+commits must scale to many concurrent commits. The current transaction commit
+code does not break down even when there are transactions coming from 2048
+processors at once. The current transaction code does not go any faster than if
+there was only one CPU using it, but it does not slow down either.
+
+As a result, the delayed logging transaction commit code needs to be designed
+for concurrency from the ground up. It is obvious that there are serialisation
+points in the design - the three important ones are:
+
+ 1. Locking out new transaction commits while flushing the CIL
+ 2. Adding items to the CIL and updating item space accounting
+ 3. Checkpoint commit ordering
+
+Looking at the transaction commit and CIL flushing interactions, it is clear
+that we have a many-to-one interaction here. That is, the only restriction on
+the number of concurrent transactions that can be trying to commit at once is
+the amount of space available in the log for their reservations. The practical
+limit here is in the order of several hundred concurrent transactions for a
+128MB log, which means that it is generally one per CPU in a machine.
+
+The amount of time a transaction commit needs to hold out a flush is a
+relatively long period of time - the pinning of log items needs to be done
+while we are holding out a CIL flush, so at the moment that means it is held
+across the formatting of the objects into memory buffers (i.e. while memcpy()s
+are in progress). Ultimately a two pass algorithm where the formatting is done
+separately to the pinning of objects could be used to reduce the hold time of
+the transaction commit side.
+
+Because of the number of potential transaction commit side holders, the lock
+really needs to be a sleeping lock - if the CIL flush takes the lock, we do not
+want every other CPU in the machine spinning on the CIL lock. Given that
+flushing the CIL could involve walking a list of tens of thousands of log
+items, it will get held for a significant time and so spin contention is a
+significant concern. Preventing lots of CPUs spinning doing nothing is the
+main reason for choosing a sleeping lock even though nothing in either the
+transaction commit or CIL flush side sleeps with the lock held.
+
+It should also be noted that CIL flushing is also a relatively rare operation
+compared to transaction commit for asynchronous transaction workloads - only
+time will tell if using a read-write semaphore for exclusion will limit
+transaction commit concurrency due to cache line bouncing of the lock on the
+read side.
+
+The second serialisation point is on the transaction commit side where items
+are inserted into the CIL. Because transactions can enter this code
+concurrently, the CIL needs to be protected separately from the above
+commit/flush exclusion. It also needs to be an exclusive lock but it is only
+held for a very short time and so a spin lock is appropriate here. It is
+possible that this lock will become a contention point, but given the short
+hold time once per transaction I think that contention is unlikely.
+
+The final serialisation point is the checkpoint commit record ordering code
+that is run as part of the checkpoint commit and log force sequencing. The code
+path that triggers a CIL flush (i.e. whatever triggers the log force) will enter
+an ordering loop after writing all the log vectors into the log buffers but
+before writing the commit record. This loop walks the list of committing
+checkpoints and needs to block waiting for checkpoints to complete their commit
+record write. As a result it needs a lock and a wait variable. Log force
+sequencing also requires the same lock, list walk, and blocking mechanism to
+ensure completion of checkpoints.
+
+These two sequencing operations can use the mechanism even though the
+events they are waiting for are different. The checkpoint commit record
+sequencing needs to wait until checkpoint contexts contain a commit LSN
+(obtained through completion of a commit record write) while log force
+sequencing needs to wait until previous checkpoint contexts are removed from
+the committing list (i.e. they've completed). A simple wait variable and
+broadcast wakeups (thundering herds) has been used to implement these two
+serialisation queues. They use the same lock as the CIL, too. If we see too
+much contention on the CIL lock, or too many context switches as a result of
+the broadcast wakeups these operations can be put under a new spinlock and
+given separate wait lists to reduce lock contention and the number of processes
+woken by the wrong event.
+
+
+Lifecycle Changes
+
+The existing log item life cycle is as follows:
+
+ 1. Transaction allocate
+ 2. Transaction reserve
+ 3. Lock item
+ 4. Join item to transaction
+ If not already attached,
+ Allocate log item
+ Attach log item to owner item
+ Attach log item to transaction
+ 5. Modify item
+ Record modifications in log item
+ 6. Transaction commit
+ Pin item in memory
+ Format item into log buffer
+ Write commit LSN into transaction
+ Unlock item
+ Attach transaction to log buffer
+
+ <log buffer IO dispatched>
+ <log buffer IO completes>
+
+ 7. Transaction completion
+ Mark log item committed
+ Insert log item into AIL
+ Write commit LSN into log item
+ Unpin log item
+ 8. AIL traversal
+ Lock item
+ Mark log item clean
+ Flush item to disk
+
+ <item IO completion>
+
+ 9. Log item removed from AIL
+ Moves log tail
+ Item unlocked
+
+Essentially, steps 1-6 operate independently from step 7, which is also
+independent of steps 8-9. An item can be locked in steps 1-6 or steps 8-9
+at the same time step 7 is occurring, but only steps 1-6 or 8-9 can occur
+at the same time. If the log item is in the AIL or between steps 6 and 7
+and steps 1-6 are re-entered, then the item is relogged. Only when steps 8-9
+are entered and completed is the object considered clean.
+
+With delayed logging, there are new steps inserted into the life cycle:
+
+ 1. Transaction allocate
+ 2. Transaction reserve
+ 3. Lock item
+ 4. Join item to transaction
+ If not already attached,
+ Allocate log item
+ Attach log item to owner item
+ Attach log item to transaction
+ 5. Modify item
+ Record modifications in log item
+ 6. Transaction commit
+ Pin item in memory if not pinned in CIL
+ Format item into log vector + buffer
+ Attach log vector and buffer to log item
+ Insert log item into CIL
+ Write CIL context sequence into transaction
+ Unlock item
+
+ <next log force>
+
+ 7. CIL push
+ lock CIL flush
+ Chain log vectors and buffers together
+ Remove items from CIL
+ unlock CIL flush
+ write log vectors into log
+ sequence commit records
+ attach checkpoint context to log buffer
+
+ <log buffer IO dispatched>
+ <log buffer IO completes>
+
+ 8. Checkpoint completion
+ Mark log item committed
+ Insert item into AIL
+ Write commit LSN into log item
+ Unpin log item
+ 9. AIL traversal
+ Lock item
+ Mark log item clean
+ Flush item to disk
+ <item IO completion>
+ 10. Log item removed from AIL
+ Moves log tail
+ Item unlocked
+
+From this, it can be seen that the only life cycle differences between the two
+logging methods are in the middle of the life cycle - they still have the same
+beginning and end and execution constraints. The only differences are in the
+commiting of the log items to the log itself and the completion processing.
+Hence delayed logging should not introduce any constraints on log item
+behaviour, allocation or freeing that don't already exist.
+
+As a result of this zero-impact "insertion" of delayed logging infrastructure
+and the design of the internal structures to avoid on disk format changes, we
+can basically switch between delayed logging and the existing mechanism with a
+mount option. Fundamentally, there is no reason why the log manager would not
+be able to swap methods automatically and transparently depending on load
+characteristics, but this should not be necessary if delayed logging works as
+designed.
+
+Roadmap:
+
+2.6.35 Inclusion in mainline as an experimental mount option
+ => approximately 2-3 months to merge window
+ => needs to be in xfs-dev tree in 4-6 weeks
+ => code is nearing readiness for review
+
+2.6.37 Remove experimental tag from mount option
+ => should be roughly 6 months after initial merge
+ => enough time to:
+ => gain confidence and fix problems reported by early
+ adopters (a.k.a. guinea pigs)
+ => address worst performance regressions and undesired
+ behaviours
+ => start tuning/optimising code for parallelism
+ => start tuning/optimising algorithms consuming
+ excessive CPU time
+
+2.6.39 Switch default mount option to use delayed logging
+ => should be roughly 12 months after initial merge
+ => enough time to shake out remaining problems before next round of
+ enterprise distro kernel rebases
diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index b4769e4..c8fb13f 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -77,6 +77,7 @@ xfs-y += xfs_alloc.o \
xfs_itable.o \
xfs_dfrag.o \
xfs_log.o \
+ xfs_log_cil.o \
xfs_log_recover.o \
xfs_mount.o \
xfs_mru_cache.o \
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index f01de3c..649ade8 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -37,6 +37,7 @@
#include "xfs_sb.h"
#include "xfs_inum.h"
+#include "xfs_log.h"
#include "xfs_ag.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
@@ -850,6 +851,12 @@ xfs_buf_lock_value(
* Note that this in no way locks the underlying pages, so it is only
* useful for synchronizing concurrent use of buffer objects, not for
* synchronizing independent access to the underlying pages.
+ *
+ * If we come across a stale, pinned, locked buffer, we know that we
+ * are being asked to lock a buffer that has been reallocated. Because
+ * it is pinned, we know that the log has not been pushed to disk and
+ * hence it will still be locked. Rather than sleeping until someone
+ * else pushes the log, push it ourselves before trying to get the lock.
*/
void
xfs_buf_lock(
@@ -857,6 +864,8 @@ xfs_buf_lock(
{
trace_xfs_buf_lock(bp, _RET_IP_);
+ if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE))
+ xfs_log_force(bp->b_mount, 0);
if (atomic_read(&bp->b_io_remaining))
blk_run_address_space(bp->b_target->bt_mapping);
down(&bp->b_sema);
diff --git a/fs/xfs/linux-2.6/xfs_quotaops.c b/fs/xfs/linux-2.6/xfs_quotaops.c
index e31bf21..9ac8aea 100644
--- a/fs/xfs/linux-2.6/xfs_quotaops.c
+++ b/fs/xfs/linux-2.6/xfs_quotaops.c
@@ -19,6 +19,7 @@
#include "xfs_dmapi.h"
#include "xfs_sb.h"
#include "xfs_inum.h"
+#include "xfs_log.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_quota.h"
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index f24dbe5..f2d1718 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -119,6 +119,8 @@ mempool_t *xfs_ioend_pool;
#define MNTOPT_DMAPI "dmapi" /* DMI enabled (DMAPI / XDSM) */
#define MNTOPT_XDSM "xdsm" /* DMI enabled (DMAPI / XDSM) */
#define MNTOPT_DMI "dmi" /* DMI enabled (DMAPI / XDSM) */
+#define MNTOPT_DELAYLOG "delaylog" /* Delayed loging enabled */
+#define MNTOPT_NODELAYLOG "nodelaylog" /* Delayed loging disabled */
/*
* Table driven mount option parser.
@@ -374,6 +376,13 @@ xfs_parseargs(
mp->m_flags |= XFS_MOUNT_DMAPI;
} else if (!strcmp(this_char, MNTOPT_DMI)) {
mp->m_flags |= XFS_MOUNT_DMAPI;
+ } else if (!strcmp(this_char, MNTOPT_DELAYLOG)) {
+ mp->m_flags |= XFS_MOUNT_DELAYLOG;
+ cmn_err(CE_WARN,
+ "Enabling EXPERIMENTAL delayed logging feature "
+ "- use at your own risk.\n");
+ } else if (!strcmp(this_char, MNTOPT_NODELAYLOG)) {
+ mp->m_flags &= ~XFS_MOUNT_DELAYLOG;
} else if (!strcmp(this_char, "ihashsize")) {
cmn_err(CE_WARN,
"XFS: ihashsize no longer used, option is deprecated.");
@@ -535,6 +544,7 @@ xfs_showargs(
{ XFS_MOUNT_FILESTREAMS, "," MNTOPT_FILESTREAM },
{ XFS_MOUNT_DMAPI, "," MNTOPT_DMAPI },
{ XFS_MOUNT_GRPID, "," MNTOPT_GRPID },
+ { XFS_MOUNT_DELAYLOG, "," MNTOPT_DELAYLOG },
{ 0, NULL }
};
static struct proc_xfs_info xfs_info_unset[] = {
@@ -1755,7 +1765,7 @@ xfs_init_zones(void)
* but it is much faster.
*/
xfs_buf_item_zone = kmem_zone_init((sizeof(xfs_buf_log_item_t) +
- (((XFS_MAX_BLOCKSIZE / XFS_BLI_CHUNK) /
+ (((XFS_MAX_BLOCKSIZE / XFS_BLF_CHUNK) /
NBWORD) * sizeof(int))), "xfs_buf_item");
if (!xfs_buf_item_zone)
goto out_destroy_trans_zone;
diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h
index 8a319cf..ff6bc79 100644
--- a/fs/xfs/linux-2.6/xfs_trace.h
+++ b/fs/xfs/linux-2.6/xfs_trace.h
@@ -1059,83 +1059,112 @@ TRACE_EVENT(xfs_bunmap,
);
+#define XFS_BUSY_SYNC \
+ { 0, "async" }, \
+ { 1, "sync" }
+
TRACE_EVENT(xfs_alloc_busy,
- TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, xfs_agblock_t agbno,
- xfs_extlen_t len, int slot),
- TP_ARGS(mp, agno, agbno, len, slot),
+ TP_PROTO(struct xfs_trans *trans, xfs_agnumber_t agno,
+ xfs_agblock_t agbno, xfs_extlen_t len, int sync),
+ TP_ARGS(trans, agno, agbno, len, sync),
TP_STRUCT__entry(
__field(dev_t, dev)
+ __field(struct xfs_trans *, tp)
+ __field(int, tid)
__field(xfs_agnumber_t, agno)
__field(xfs_agblock_t, agbno)
__field(xfs_extlen_t, len)
- __field(int, slot)
+ __field(int, sync)
),
TP_fast_assign(
- __entry->dev = mp->m_super->s_dev;
+ __entry->dev = trans->t_mountp->m_super->s_dev;
+ __entry->tp = trans;
+ __entry->tid = trans->t_ticket->t_tid;
__entry->agno = agno;
__entry->agbno = agbno;
__entry->len = len;
- __entry->slot = slot;
+ __entry->sync = sync;
),
- TP_printk("dev %d:%d agno %u agbno %u len %u slot %d",
+ TP_printk("dev %d:%d trans 0x%p tid 0x%x agno %u agbno %u len %u %s",
MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->tp,
+ __entry->tid,
__entry->agno,
__entry->agbno,
__entry->len,
- __entry->slot)
+ __print_symbolic(__entry->sync, XFS_BUSY_SYNC))
);
-#define XFS_BUSY_STATES \
- { 0, "found" }, \
- { 1, "missing" }
-
TRACE_EVENT(xfs_alloc_unbusy,
TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
- int slot, int found),
- TP_ARGS(mp, agno, slot, found),
+ xfs_agblock_t agbno, xfs_extlen_t len),
+ TP_ARGS(mp, agno, agbno, len),
TP_STRUCT__entry(
__field(dev_t, dev)
__field(xfs_agnumber_t, agno)
- __field(int, slot)
- __field(int, found)
+ __field(xfs_agblock_t, agbno)
+ __field(xfs_extlen_t, len)
),
TP_fast_assign(
__entry->dev = mp->m_super->s_dev;
__entry->agno = agno;
- __entry->slot = slot;
- __entry->found = found;
+ __entry->agbno = agbno;
+ __entry->len = len;
),
- TP_printk("dev %d:%d agno %u slot %d %s",
+ TP_printk("dev %d:%d agno %u agbno %u len %u",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->agno,
- __entry->slot,
- __print_symbolic(__entry->found, XFS_BUSY_STATES))
+ __entry->agbno,
+ __entry->len)
);
+#define XFS_BUSY_STATES \
+ { 0, "missing" }, \
+ { 1, "found" }
+
TRACE_EVENT(xfs_alloc_busysearch,
- TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, xfs_agblock_t agbno,
- xfs_extlen_t len, xfs_lsn_t lsn),
- TP_ARGS(mp, agno, agbno, len, lsn),
+ TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
+ xfs_agblock_t agbno, xfs_extlen_t len, int found),
+ TP_ARGS(mp, agno, agbno, len, found),
TP_STRUCT__entry(
__field(dev_t, dev)
__field(xfs_agnumber_t, agno)
__field(xfs_agblock_t, agbno)
__field(xfs_extlen_t, len)
- __field(xfs_lsn_t, lsn)
+ __field(int, found)
),
TP_fast_assign(
__entry->dev = mp->m_super->s_dev;
__entry->agno = agno;
__entry->agbno = agbno;
__entry->len = len;
- __entry->lsn = lsn;
+ __entry->found = found;
),
- TP_printk("dev %d:%d agno %u agbno %u len %u force lsn 0x%llx",
+ TP_printk("dev %d:%d agno %u agbno %u len %u %s",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->agno,
__entry->agbno,
__entry->len,
+ __print_symbolic(__entry->found, XFS_BUSY_STATES))
+);
+
+TRACE_EVENT(xfs_trans_commit_lsn,
+ TP_PROTO(struct xfs_trans *trans),
+ TP_ARGS(trans),
+ TP_STRUCT__entry(
+ __field(dev_t, dev)
+ __field(struct xfs_trans *, tp)
+ __field(xfs_lsn_t, lsn)
+ ),
+ TP_fast_assign(
+ __entry->dev = trans->t_mountp->m_super->s_dev;
+ __entry->tp = trans;
+ __entry->lsn = trans->t_commit_lsn;
+ ),
+ TP_printk("dev %d:%d trans 0x%p commit_lsn 0x%llx",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ __entry->tp,
__entry->lsn)
);
diff --git a/fs/xfs/quota/xfs_dquot.c b/fs/xfs/quota/xfs_dquot.c
index b89ec5d..585e763 100644
--- a/fs/xfs/quota/xfs_dquot.c
+++ b/fs/xfs/quota/xfs_dquot.c
@@ -344,9 +344,9 @@ xfs_qm_init_dquot_blk(
for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++)
xfs_qm_dqinit_core(curid, type, d);
xfs_trans_dquot_buf(tp, bp,
- (type & XFS_DQ_USER ? XFS_BLI_UDQUOT_BUF :
- ((type & XFS_DQ_PROJ) ? XFS_BLI_PDQUOT_BUF :
- XFS_BLI_GDQUOT_BUF)));
+ (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF :
+ ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF :
+ XFS_BLF_GDQUOT_BUF)));
xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1);
}
diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h
index abb8222..401f364 100644
--- a/fs/xfs/xfs_ag.h
+++ b/fs/xfs/xfs_ag.h
@@ -175,14 +175,20 @@ typedef struct xfs_agfl {
} xfs_agfl_t;
/*
- * Busy block/extent entry. Used in perag to mark blocks that have been freed
- * but whose transactions aren't committed to disk yet.
+ * Busy block/extent entry. Indexed by a rbtree in perag to mark blocks that
+ * have been freed but whose transactions aren't committed to disk yet.
+ *
+ * Note that we use the transaction ID to record the transaction, not the
+ * transaction structure itself. See xfs_alloc_busy_insert() for details.
*/
-typedef struct xfs_perag_busy {
- xfs_agblock_t busy_start;
- xfs_extlen_t busy_length;
- struct xfs_trans *busy_tp; /* transaction that did the free */
-} xfs_perag_busy_t;
+struct xfs_busy_extent {
+ struct rb_node rb_node; /* ag by-bno indexed search tree */
+ struct list_head list; /* transaction busy extent list */
+ xfs_agnumber_t agno;
+ xfs_agblock_t bno;
+ xfs_extlen_t length;
+ xlog_tid_t tid; /* transaction that created this */
+};
/*
* Per-ag incore structure, copies of information in agf and agi,
@@ -216,7 +222,8 @@ typedef struct xfs_perag {
xfs_agino_t pagl_leftrec;
xfs_agino_t pagl_rightrec;
#ifdef __KERNEL__
- spinlock_t pagb_lock; /* lock for pagb_list */
+ spinlock_t pagb_lock; /* lock for pagb_tree */
+ struct rb_root pagb_tree; /* ordered tree of busy extents */
atomic_t pagf_fstrms; /* # of filestreams active in this AG */
@@ -226,7 +233,6 @@ typedef struct xfs_perag {
int pag_ici_reclaimable; /* reclaimable inodes */
#endif
int pagb_count; /* pagb slots in use */
- xfs_perag_busy_t pagb_list[XFS_PAGB_NUM_SLOTS]; /* unstable blocks */
} xfs_perag_t;
/*
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 94cddbf..a7fbe8a 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -46,11 +46,9 @@
#define XFSA_FIXUP_BNO_OK 1
#define XFSA_FIXUP_CNT_OK 2
-STATIC void
-xfs_alloc_search_busy(xfs_trans_t *tp,
- xfs_agnumber_t agno,
- xfs_agblock_t bno,
- xfs_extlen_t len);
+static int
+xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno,
+ xfs_agblock_t bno, xfs_extlen_t len);
/*
* Prototypes for per-ag allocation routines
@@ -540,9 +538,16 @@ xfs_alloc_ag_vextent(
be32_to_cpu(agf->agf_length));
xfs_alloc_log_agf(args->tp, args->agbp,
XFS_AGF_FREEBLKS);
- /* search the busylist for these blocks */
- xfs_alloc_search_busy(args->tp, args->agno,
- args->agbno, args->len);
+ /*
+ * Search the busylist for these blocks and mark the
+ * transaction as synchronous if blocks are found. This
+ * avoids the need to block due to a synchronous log
+ * force to ensure correct ordering as the synchronous
+ * transaction will guarantee that for us.
+ */
+ if (xfs_alloc_busy_search(args->mp, args->agno,
+ args->agbno, args->len))
+ xfs_trans_set_sync(args->tp);
}
if (!args->isfl)
xfs_trans_mod_sb(args->tp,
@@ -1693,7 +1698,7 @@ xfs_free_ag_extent(
* when the iclog commits to disk. If a busy block is allocated,
* the iclog is pushed up to the LSN that freed the block.
*/
- xfs_alloc_mark_busy(tp, agno, bno, len);
+ xfs_alloc_busy_insert(tp, agno, bno, len);
return 0;
error0:
@@ -1989,14 +1994,20 @@ xfs_alloc_get_freelist(
*bnop = bno;
/*
- * As blocks are freed, they are added to the per-ag busy list
- * and remain there until the freeing transaction is committed to
- * disk. Now that we have allocated blocks, this list must be
- * searched to see if a block is being reused. If one is, then
- * the freeing transaction must be pushed to disk NOW by forcing
- * to disk all iclogs up that transaction's LSN.
+ * As blocks are freed, they are added to the per-ag busy list and
+ * remain there until the freeing transaction is committed to disk.
+ * Now that we have allocated blocks, this list must be searched to see
+ * if a block is being reused. If one is, then the freeing transaction
+ * must be pushed to disk before this transaction.
+ *
+ * We do this by setting the current transaction to a sync transaction
+ * which guarantees that the freeing transaction is on disk before this
+ * transaction. This is done instead of a synchronous log force here so
+ * that we don't sit and wait with the AGF locked in the transaction
+ * during the log force.
*/
- xfs_alloc_search_busy(tp, be32_to_cpu(agf->agf_seqno), bno, 1);
+ if (xfs_alloc_busy_search(mp, be32_to_cpu(agf->agf_seqno), bno, 1))
+ xfs_trans_set_sync(tp);
return 0;
}
@@ -2201,7 +2212,7 @@ xfs_alloc_read_agf(
be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
spin_lock_init(&pag->pagb_lock);
pag->pagb_count = 0;
- memset(pag->pagb_list, 0, sizeof(pag->pagb_list));
+ pag->pagb_tree = RB_ROOT;
pag->pagf_init = 1;
}
#ifdef DEBUG
@@ -2479,127 +2490,263 @@ error0:
* list is reused, the transaction that freed it must be forced to disk
* before continuing to use the block.
*
- * xfs_alloc_mark_busy - add to the per-ag busy list
- * xfs_alloc_clear_busy - remove an item from the per-ag busy list
+ * xfs_alloc_busy_insert - add to the per-ag busy list
+ * xfs_alloc_busy_clear - remove an item from the per-ag busy list
+ * xfs_alloc_busy_search - search for a busy extent
+ */
+
+/*
+ * Insert a new extent into the busy tree.
+ *
+ * The busy extent tree is indexed by the start block of the busy extent.
+ * there can be multiple overlapping ranges in the busy extent tree but only
+ * ever one entry at a given start block. The reason for this is that
+ * multi-block extents can be freed, then smaller chunks of that extent
+ * allocated and freed again before the first transaction commit is on disk.
+ * If the exact same start block is freed a second time, we have to wait for
+ * that busy extent to pass out of the tree before the new extent is inserted.
+ * There are two main cases we have to handle here.
+ *
+ * The first case is a transaction that triggers a "free - allocate - free"
+ * cycle. This can occur during btree manipulations as a btree block is freed
+ * to the freelist, then allocated from the free list, then freed again. In
+ * this case, the second extxpnet free is what triggers the duplicate and as
+ * such the transaction IDs should match. Because the extent was allocated in
+ * this transaction, the transaction must be marked as synchronous. This is
+ * true for all cases where the free/alloc/free occurs in the one transaction,
+ * hence the addition of the ASSERT(tp->t_flags & XFS_TRANS_SYNC) to this case.
+ * This serves to catch violations of the second case quite effectively.
+ *
+ * The second case is where the free/alloc/free occur in different
+ * transactions. In this case, the thread freeing the extent the second time
+ * can't mark the extent busy immediately because it is already tracked in a
+ * transaction that may be committing. When the log commit for the existing
+ * busy extent completes, the busy extent will be removed from the tree. If we
+ * allow the second busy insert to continue using that busy extent structure,
+ * it can be freed before this transaction is safely in the log. Hence our
+ * only option in this case is to force the log to remove the existing busy
+ * extent from the list before we insert the new one with the current
+ * transaction ID.
+ *
+ * The problem we are trying to avoid in the free-alloc-free in separate
+ * transactions is most easily described with a timeline:
+ *
+ * Thread 1 Thread 2 Thread 3 xfslogd
+ * xact alloc
+ * free X
+ * mark busy
+ * commit xact
+ * free xact
+ * xact alloc
+ * alloc X
+ * busy search
+ * mark xact sync
+ * commit xact
+ * free xact
+ * force log
+ * checkpoint starts
+ * ....
+ * xact alloc
+ * free X
+ * mark busy
+ * finds match
+ * *** KABOOM! ***
+ * ....
+ * log IO completes
+ * unbusy X
+ * checkpoint completes
+ *
+ * By issuing a log force in thread 3 @ "KABOOM", the thread will block until
+ * the checkpoint completes, and the busy extent it matched will have been
+ * removed from the tree when it is woken. Hence it can then continue safely.
+ *
+ * However, to ensure this matching process is robust, we need to use the
+ * transaction ID for identifying transaction, as delayed logging results in
+ * the busy extent and transaction lifecycles being different. i.e. the busy
+ * extent is active for a lot longer than the transaction. Hence the
+ * transaction structure can be freed and reallocated, then mark the same
+ * extent busy again in the new transaction. In this case the new transaction
+ * will have a different tid but can have the same address, and hence we need
+ * to check against the tid.
+ *
+ * Future: for delayed logging, we could avoid the log force if the extent was
+ * first freed in the current checkpoint sequence. This, however, requires the
+ * ability to pin the current checkpoint in memory until this transaction
+ * commits to ensure that both the original free and the current one combine
+ * logically into the one checkpoint. If the checkpoint sequences are
+ * different, however, we still need to wait on a log force.
*/
void
-xfs_alloc_mark_busy(xfs_trans_t *tp,
- xfs_agnumber_t agno,
- xfs_agblock_t bno,
- xfs_extlen_t len)
+xfs_alloc_busy_insert(
+ struct xfs_trans *tp,
+ xfs_agnumber_t agno,
+ xfs_agblock_t bno,
+ xfs_extlen_t len)
{
- xfs_perag_busy_t *bsy;
+ struct xfs_busy_extent *new;
+ struct xfs_busy_extent *busyp;
struct xfs_perag *pag;
- int n;
+ struct rb_node **rbp;
+ struct rb_node *parent;
+ int match;
- pag = xfs_perag_get(tp->t_mountp, agno);
- spin_lock(&pag->pagb_lock);
- /* search pagb_list for an open slot */
- for (bsy = pag->pagb_list, n = 0;
- n < XFS_PAGB_NUM_SLOTS;
- bsy++, n++) {
- if (bsy->busy_tp == NULL) {
- break;
- }
+ new = kmem_zalloc(sizeof(struct xfs_busy_extent), KM_MAYFAIL);
+ if (!new) {
+ /*
+ * No Memory! Since it is now not possible to track the free
+ * block, make this a synchronous transaction to insure that
+ * the block is not reused before this transaction commits.
+ */
+ trace_xfs_alloc_busy(tp, agno, bno, len, 1);
+ xfs_trans_set_sync(tp);
+ return;
}
- trace_xfs_alloc_busy(tp->t_mountp, agno, bno, len, n);
+ new->agno = agno;
+ new->bno = bno;
+ new->length = len;
+ new->tid = xfs_log_get_trans_ident(tp);
- if (n < XFS_PAGB_NUM_SLOTS) {
- bsy = &pag->pagb_list[n];
- pag->pagb_count++;
- bsy->busy_start = bno;
- bsy->busy_length = len;
- bsy->busy_tp = tp;
- xfs_trans_add_busy(tp, agno, n);
- } else {
+ INIT_LIST_HEAD(&new->list);
+
+ /* trace before insert to be able to see failed inserts */
+ trace_xfs_alloc_busy(tp, agno, bno, len, 0);
+
+ pag = xfs_perag_get(tp->t_mountp, new->agno);
+restart:
+ spin_lock(&pag->pagb_lock);
+ rbp = &pag->pagb_tree.rb_node;
+ parent = NULL;
+ busyp = NULL;
+ match = 0;
+ while (*rbp && match >= 0) {
+ parent = *rbp;
+ busyp = rb_entry(parent, struct xfs_busy_extent, rb_node);
+
+ if (new->bno < busyp->bno) {
+ /* may overlap, but exact start block is lower */
+ rbp = &(*rbp)->rb_left;
+ if (new->bno + new->length > busyp->bno)
+ match = busyp->tid == new->tid ? 1 : -1;
+ } else if (new->bno > busyp->bno) {
+ /* may overlap, but exact start block is higher */
+ rbp = &(*rbp)->rb_right;
+ if (bno < busyp->bno + busyp->length)
+ match = busyp->tid == new->tid ? 1 : -1;
+ } else {
+ match = busyp->tid == new->tid ? 1 : -1;
+ break;
+ }
+ }
+ if (match < 0) {
+ /* overlap marked busy in different transaction */
+ spin_unlock(&pag->pagb_lock);
+ xfs_log_force(tp->t_mountp, XFS_LOG_SYNC);
+ goto restart;
+ }
+ if (match > 0) {
/*
- * The busy list is full! Since it is now not possible to
- * track the free block, make this a synchronous transaction
- * to insure that the block is not reused before this
- * transaction commits.
+ * overlap marked busy in same transaction. Update if exact
+ * start block match, otherwise combine the busy extents into
+ * a single range.
*/
- xfs_trans_set_sync(tp);
- }
+ if (busyp->bno == new->bno) {
+ busyp->length = max(busyp->length, new->length);
+ spin_unlock(&pag->pagb_lock);
+ ASSERT(tp->t_flags & XFS_TRANS_SYNC);
+ xfs_perag_put(pag);
+ kmem_free(new);
+ return;
+ }
+ rb_erase(&busyp->rb_node, &pag->pagb_tree);
+ new->length = max(busyp->bno + busyp->length,
+ new->bno + new->length) -
+ min(busyp->bno, new->bno);
+ new->bno = min(busyp->bno, new->bno);
+ } else
+ busyp = NULL;
+ rb_link_node(&new->rb_node, parent, rbp);
+ rb_insert_color(&new->rb_node, &pag->pagb_tree);
+
+ list_add(&new->list, &tp->t_busy);
spin_unlock(&pag->pagb_lock);
xfs_perag_put(pag);
+ kmem_free(busyp);
}
-void
-xfs_alloc_clear_busy(xfs_trans_t *tp,
- xfs_agnumber_t agno,
- int idx)
+/*
+ * Search for a busy extent within the range of the extent we are about to
+ * allocate. You need to be holding the busy extent tree lock when calling
+ * xfs_alloc_busy_search(). This function returns 0 for no overlapping busy
+ * extent, -1 for an overlapping but not exact busy extent, and 1 for an exact
+ * match. This is done so that a non-zero return indicates an overlap that
+ * will require a synchronous transaction, but it can still be
+ * used to distinguish between a partial or exact match.
+ */
+static int
+xfs_alloc_busy_search(
+ struct xfs_mount *mp,
+ xfs_agnumber_t agno,
+ xfs_agblock_t bno,
+ xfs_extlen_t len)
{
struct xfs_perag *pag;
- xfs_perag_busy_t *list;
+ struct rb_node *rbp;
+ struct xfs_busy_extent *busyp;
+ int match = 0;
- ASSERT(idx < XFS_PAGB_NUM_SLOTS);
- pag = xfs_perag_get(tp->t_mountp, agno);
+ pag = xfs_perag_get(mp, agno);
spin_lock(&pag->pagb_lock);
- list = pag->pagb_list;
- trace_xfs_alloc_unbusy(tp->t_mountp, agno, idx, list[idx].busy_tp == tp);
-
- if (list[idx].busy_tp == tp) {
- list[idx].busy_tp = NULL;
- pag->pagb_count--;
+ rbp = pag->pagb_tree.rb_node;
+
+ /* find closest start bno overlap */
+ while (rbp) {
+ busyp = rb_entry(rbp, struct xfs_busy_extent, rb_node);
+ if (bno < busyp->bno) {
+ /* may overlap, but exact start block is lower */
+ if (bno + len > busyp->bno)
+ match = -1;
+ rbp = rbp->rb_left;
+ } else if (bno > busyp->bno) {
+ /* may overlap, but exact start block is higher */
+ if (bno < busyp->bno + busyp->length)
+ match = -1;
+ rbp = rbp->rb_right;
+ } else {
+ /* bno matches busyp, length determines exact match */
+ match = (busyp->length == len) ? 1 : -1;
+ break;
+ }
}
-
spin_unlock(&pag->pagb_lock);
+ trace_xfs_alloc_busysearch(mp, agno, bno, len, !!match);
xfs_perag_put(pag);
+ return match;
}
-
-/*
- * If we find the extent in the busy list, force the log out to get the
- * extent out of the busy list so the caller can use it straight away.
- */
-STATIC void
-xfs_alloc_search_busy(xfs_trans_t *tp,
- xfs_agnumber_t agno,
- xfs_agblock_t bno,
- xfs_extlen_t len)
+void
+xfs_alloc_busy_clear(
+ struct xfs_mount *mp,
+ struct xfs_busy_extent *busyp)
{
struct xfs_perag *pag;
- xfs_perag_busy_t *bsy;
- xfs_agblock_t uend, bend;
- xfs_lsn_t lsn = 0;
- int cnt;
- pag = xfs_perag_get(tp->t_mountp, agno);
- spin_lock(&pag->pagb_lock);
- cnt = pag->pagb_count;
+ trace_xfs_alloc_unbusy(mp, busyp->agno, busyp->bno,
+ busyp->length);
- /*
- * search pagb_list for this slot, skipping open slots. We have to
- * search the entire array as there may be multiple overlaps and
- * we have to get the most recent LSN for the log force to push out
- * all the transactions that span the range.
- */
- uend = bno + len - 1;
- for (cnt = 0; cnt < pag->pagb_count; cnt++) {
- bsy = &pag->pagb_list[cnt];
- if (!bsy->busy_tp)
- continue;
+ ASSERT(xfs_alloc_busy_search(mp, busyp->agno, busyp->bno,
+ busyp->length) == 1);
- bend = bsy->busy_start + bsy->busy_length - 1;
- if (bno > bend || uend < bsy->busy_start)
- continue;
+ list_del_init(&busyp->list);
- /* (start1,length1) within (start2, length2) */
- if (XFS_LSN_CMP(bsy->busy_tp->t_commit_lsn, lsn) > 0)
- lsn = bsy->busy_tp->t_commit_lsn;
- }
+ pag = xfs_perag_get(mp, busyp->agno);
+ spin_lock(&pag->pagb_lock);
+ rb_erase(&busyp->rb_node, &pag->pagb_tree);
spin_unlock(&pag->pagb_lock);
xfs_perag_put(pag);
- trace_xfs_alloc_busysearch(tp->t_mountp, agno, bno, len, lsn);
- /*
- * If a block was found, force the log through the LSN of the
- * transaction that freed the block
- */
- if (lsn)
- xfs_log_force_lsn(tp->t_mountp, lsn, XFS_LOG_SYNC);
+ kmem_free(busyp);
}
diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h
index 599bffa..6d05199 100644
--- a/fs/xfs/xfs_alloc.h
+++ b/fs/xfs/xfs_alloc.h
@@ -22,6 +22,7 @@ struct xfs_buf;
struct xfs_mount;
struct xfs_perag;
struct xfs_trans;
+struct xfs_busy_extent;
/*
* Freespace allocation types. Argument to xfs_alloc_[v]extent.
@@ -119,15 +120,13 @@ xfs_alloc_longest_free_extent(struct xfs_mount *mp,
#ifdef __KERNEL__
void
-xfs_alloc_mark_busy(xfs_trans_t *tp,
+xfs_alloc_busy_insert(xfs_trans_t *tp,
xfs_agnumber_t agno,
xfs_agblock_t bno,
xfs_extlen_t len);
void
-xfs_alloc_clear_busy(xfs_trans_t *tp,
- xfs_agnumber_t ag,
- int idx);
+xfs_alloc_busy_clear(struct xfs_mount *mp, struct xfs_busy_extent *busyp);
#endif /* __KERNEL__ */
diff --git a/fs/xfs/xfs_alloc_btree.c b/fs/xfs/xfs_alloc_btree.c
index b726e10..83f4942 100644
--- a/fs/xfs/xfs_alloc_btree.c
+++ b/fs/xfs/xfs_alloc_btree.c
@@ -134,7 +134,7 @@ xfs_allocbt_free_block(
* disk. If a busy block is allocated, the iclog is pushed up to the
* LSN that freed the block.
*/
- xfs_alloc_mark_busy(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1);
+ xfs_alloc_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1);
xfs_trans_agbtree_delta(cur->bc_tp, -1);
return 0;
}
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 240340a..02a8098 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -64,7 +64,7 @@ xfs_buf_item_log_debug(
nbytes = last - first + 1;
bfset(bip->bli_logged, first, nbytes);
for (x = 0; x < nbytes; x++) {
- chunk_num = byte >> XFS_BLI_SHIFT;
+ chunk_num = byte >> XFS_BLF_SHIFT;
word_num = chunk_num >> BIT_TO_WORD_SHIFT;
bit_num = chunk_num & (NBWORD - 1);
wordp = &(bip->bli_format.blf_data_map[word_num]);
@@ -166,7 +166,7 @@ xfs_buf_item_size(
* cancel flag in it.
*/
trace_xfs_buf_item_size_stale(bip);
- ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
+ ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL);
return 1;
}
@@ -197,9 +197,9 @@ xfs_buf_item_size(
} else if (next_bit != last_bit + 1) {
last_bit = next_bit;
nvecs++;
- } else if (xfs_buf_offset(bp, next_bit * XFS_BLI_CHUNK) !=
- (xfs_buf_offset(bp, last_bit * XFS_BLI_CHUNK) +
- XFS_BLI_CHUNK)) {
+ } else if (xfs_buf_offset(bp, next_bit * XFS_BLF_CHUNK) !=
+ (xfs_buf_offset(bp, last_bit * XFS_BLF_CHUNK) +
+ XFS_BLF_CHUNK)) {
last_bit = next_bit;
nvecs++;
} else {
@@ -254,6 +254,20 @@ xfs_buf_item_format(
vecp++;
nvecs = 1;
+ /*
+ * If it is an inode buffer, transfer the in-memory state to the
+ * format flags and clear the in-memory state. We do not transfer
+ * this state if the inode buffer allocation has not yet been committed
+ * to the log as setting the XFS_BLI_INODE_BUF flag will prevent
+ * correct replay of the inode allocation.
+ */
+ if (bip->bli_flags & XFS_BLI_INODE_BUF) {
+ if (!((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) &&
+ xfs_log_item_in_current_chkpt(&bip->bli_item)))
+ bip->bli_format.blf_flags |= XFS_BLF_INODE_BUF;
+ bip->bli_flags &= ~XFS_BLI_INODE_BUF;
+ }
+
if (bip->bli_flags & XFS_BLI_STALE) {
/*
* The buffer is stale, so all we need to log
@@ -261,7 +275,7 @@ xfs_buf_item_format(
* cancel flag in it.
*/
trace_xfs_buf_item_format_stale(bip);
- ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
+ ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL);
bip->bli_format.blf_size = nvecs;
return;
}
@@ -294,28 +308,28 @@ xfs_buf_item_format(
* keep counting and scanning.
*/
if (next_bit == -1) {
- buffer_offset = first_bit * XFS_BLI_CHUNK;
+ buffer_offset = first_bit * XFS_BLF_CHUNK;
vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
- vecp->i_len = nbits * XFS_BLI_CHUNK;
+ vecp->i_len = nbits * XFS_BLF_CHUNK;
vecp->i_type = XLOG_REG_TYPE_BCHUNK;
nvecs++;
break;
} else if (next_bit != last_bit + 1) {
- buffer_offset = first_bit * XFS_BLI_CHUNK;
+ buffer_offset = first_bit * XFS_BLF_CHUNK;
vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
- vecp->i_len = nbits * XFS_BLI_CHUNK;
+ vecp->i_len = nbits * XFS_BLF_CHUNK;
vecp->i_type = XLOG_REG_TYPE_BCHUNK;
nvecs++;
vecp++;
first_bit = next_bit;
last_bit = next_bit;
nbits = 1;
- } else if (xfs_buf_offset(bp, next_bit << XFS_BLI_SHIFT) !=
- (xfs_buf_offset(bp, last_bit << XFS_BLI_SHIFT) +
- XFS_BLI_CHUNK)) {
- buffer_offset = first_bit * XFS_BLI_CHUNK;
+ } else if (xfs_buf_offset(bp, next_bit << XFS_BLF_SHIFT) !=
+ (xfs_buf_offset(bp, last_bit << XFS_BLF_SHIFT) +
+ XFS_BLF_CHUNK)) {
+ buffer_offset = first_bit * XFS_BLF_CHUNK;
vecp->i_addr = xfs_buf_offset(bp, buffer_offset);
- vecp->i_len = nbits * XFS_BLI_CHUNK;
+ vecp->i_len = nbits * XFS_BLF_CHUNK;
vecp->i_type = XLOG_REG_TYPE_BCHUNK;
/* You would think we need to bump the nvecs here too, but we do not
* this number is used by recovery, and it gets confused by the boundary
@@ -341,10 +355,15 @@ xfs_buf_item_format(
}
/*
- * This is called to pin the buffer associated with the buf log
- * item in memory so it cannot be written out. Simply call bpin()
- * on the buffer to do this.
+ * This is called to pin the buffer associated with the buf log item in memory
+ * so it cannot be written out. Simply call bpin() on the buffer to do this.
+ *
+ * We also always take a reference to the buffer log item here so that the bli
+ * is held while the item is pinned in memory. This means that we can
+ * unconditionally drop the reference count a transaction holds when the
+ * transaction is completed.
*/
+
STATIC void
xfs_buf_item_pin(
xfs_buf_log_item_t *bip)
@@ -356,6 +375,7 @@ xfs_buf_item_pin(
ASSERT(atomic_read(&bip->bli_refcount) > 0);
ASSERT((bip->bli_flags & XFS_BLI_LOGGED) ||
(bip->bli_flags & XFS_BLI_STALE));
+ atomic_inc(&bip->bli_refcount);
trace_xfs_buf_item_pin(bip);
xfs_bpin(bp);
}
@@ -393,7 +413,7 @@ xfs_buf_item_unpin(
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
ASSERT(!(XFS_BUF_ISDELAYWRITE(bp)));
ASSERT(XFS_BUF_ISSTALE(bp));
- ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
+ ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL);
trace_xfs_buf_item_unpin_stale(bip);
/*
@@ -489,20 +509,23 @@ xfs_buf_item_trylock(
}
/*
- * Release the buffer associated with the buf log item.
- * If there is no dirty logged data associated with the
- * buffer recorded in the buf log item, then free the
- * buf log item and remove the reference to it in the
- * buffer.
+ * Release the buffer associated with the buf log item. If there is no dirty
+ * logged data associated with the buffer recorded in the buf log item, then
+ * free the buf log item and remove the reference to it in the buffer.
+ *
+ * This call ignores the recursion count. It is only called when the buffer
+ * should REALLY be unlocked, regardless of the recursion count.
*
- * This call ignores the recursion count. It is only called
- * when the buffer should REALLY be unlocked, regardless
- * of the recursion count.
+ * We unconditionally drop the transaction's reference to the log item. If the
+ * item was logged, then another reference was taken when it was pinned, so we
+ * can safely drop the transaction reference now. This also allows us to avoid
+ * potential races with the unpin code freeing the bli by not referencing the
+ * bli after we've dropped the reference count.
*
- * If the XFS_BLI_HOLD flag is set in the buf log item, then
- * free the log item if necessary but do not unlock the buffer.
- * This is for support of xfs_trans_bhold(). Make sure the
- * XFS_BLI_HOLD field is cleared if we don't free the item.
+ * If the XFS_BLI_HOLD flag is set in the buf log item, then free the log item
+ * if necessary but do not unlock the buffer. This is for support of
+ * xfs_trans_bhold(). Make sure the XFS_BLI_HOLD field is cleared if we don't
+ * free the item.
*/
STATIC void
xfs_buf_item_unlock(
@@ -514,73 +537,54 @@ xfs_buf_item_unlock(
bp = bip->bli_buf;
- /*
- * Clear the buffer's association with this transaction.
- */
+ /* Clear the buffer's association with this transaction. */
XFS_BUF_SET_FSPRIVATE2(bp, NULL);
/*
- * If this is a transaction abort, don't return early.
- * Instead, allow the brelse to happen.
- * Normally it would be done for stale (cancelled) buffers
- * at unpin time, but we'll never go through the pin/unpin
- * cycle if we abort inside commit.
+ * If this is a transaction abort, don't return early. Instead, allow
+ * the brelse to happen. Normally it would be done for stale
+ * (cancelled) buffers at unpin time, but we'll never go through the
+ * pin/unpin cycle if we abort inside commit.
*/
aborted = (bip->bli_item.li_flags & XFS_LI_ABORTED) != 0;
/*
- * If the buf item is marked stale, then don't do anything.
- * We'll unlock the buffer and free the buf item when the
- * buffer is unpinned for the last time.
+ * Before possibly freeing the buf item, determine if we should
+ * release the buffer at the end of this routine.
*/
- if (bip->bli_flags & XFS_BLI_STALE) {
- bip->bli_flags &= ~XFS_BLI_LOGGED;
- trace_xfs_buf_item_unlock_stale(bip);
- ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
- if (!aborted)
- return;
- }
+ hold = bip->bli_flags & XFS_BLI_HOLD;
+
+ /* Clear the per transaction state. */
+ bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD);
/*
- * Drop the transaction's reference to the log item if
- * it was not logged as part of the transaction. Otherwise
- * we'll drop the reference in xfs_buf_item_unpin() when
- * the transaction is really through with the buffer.
+ * If the buf item is marked stale, then don't do anything. We'll
+ * unlock the buffer and free the buf item when the buffer is unpinned
+ * for the last time.
*/
- if (!(bip->bli_flags & XFS_BLI_LOGGED)) {
- atomic_dec(&bip->bli_refcount);
- } else {
- /*
- * Clear the logged flag since this is per
- * transaction state.
- */
- bip->bli_flags &= ~XFS_BLI_LOGGED;
+ if (bip->bli_flags & XFS_BLI_STALE) {
+ trace_xfs_buf_item_unlock_stale(bip);
+ ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL);
+ if (!aborted) {
+ atomic_dec(&bip->bli_refcount);
+ return;
+ }
}
- /*
- * Before possibly freeing the buf item, determine if we should
- * release the buffer at the end of this routine.
- */
- hold = bip->bli_flags & XFS_BLI_HOLD;
trace_xfs_buf_item_unlock(bip);
/*
- * If the buf item isn't tracking any data, free it.
- * Otherwise, if XFS_BLI_HOLD is set clear it.
+ * If the buf item isn't tracking any data, free it, otherwise drop the
+ * reference we hold to it.
*/
if (xfs_bitmap_empty(bip->bli_format.blf_data_map,
- bip->bli_format.blf_map_size)) {
+ bip->bli_format.blf_map_size))
xfs_buf_item_relse(bp);
- } else if (hold) {
- bip->bli_flags &= ~XFS_BLI_HOLD;
- }
+ else
+ atomic_dec(&bip->bli_refcount);
- /*
- * Release the buffer if XFS_BLI_HOLD was not set.
- */
- if (!hold) {
+ if (!hold)
xfs_buf_relse(bp);
- }
}
/*
@@ -717,12 +721,12 @@ xfs_buf_item_init(
}
/*
- * chunks is the number of XFS_BLI_CHUNK size pieces
+ * chunks is the number of XFS_BLF_CHUNK size pieces
* the buffer can be divided into. Make sure not to
* truncate any pieces. map_size is the size of the
* bitmap needed to describe the chunks of the buffer.
*/
- chunks = (int)((XFS_BUF_COUNT(bp) + (XFS_BLI_CHUNK - 1)) >> XFS_BLI_SHIFT);
+ chunks = (int)((XFS_BUF_COUNT(bp) + (XFS_BLF_CHUNK - 1)) >> XFS_BLF_SHIFT);
map_size = (int)((chunks + NBWORD) >> BIT_TO_WORD_SHIFT);
bip = (xfs_buf_log_item_t*)kmem_zone_zalloc(xfs_buf_item_zone,
@@ -790,8 +794,8 @@ xfs_buf_item_log(
/*
* Convert byte offsets to bit numbers.
*/
- first_bit = first >> XFS_BLI_SHIFT;
- last_bit = last >> XFS_BLI_SHIFT;
+ first_bit = first >> XFS_BLF_SHIFT;
+ last_bit = last >> XFS_BLF_SHIFT;
/*
* Calculate the total number of bits to be set.
diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h
index df44545..f20bb47 100644
--- a/fs/xfs/xfs_buf_item.h
+++ b/fs/xfs/xfs_buf_item.h
@@ -41,22 +41,22 @@ typedef struct xfs_buf_log_format {
* This flag indicates that the buffer contains on disk inodes
* and requires special recovery handling.
*/
-#define XFS_BLI_INODE_BUF 0x1
+#define XFS_BLF_INODE_BUF 0x1
/*
* This flag indicates that the buffer should not be replayed
* during recovery because its blocks are being freed.
*/
-#define XFS_BLI_CANCEL 0x2
+#define XFS_BLF_CANCEL 0x2
/*
* This flag indicates that the buffer contains on disk
* user or group dquots and may require special recovery handling.
*/
-#define XFS_BLI_UDQUOT_BUF 0x4
-#define XFS_BLI_PDQUOT_BUF 0x8
-#define XFS_BLI_GDQUOT_BUF 0x10
+#define XFS_BLF_UDQUOT_BUF 0x4
+#define XFS_BLF_PDQUOT_BUF 0x8
+#define XFS_BLF_GDQUOT_BUF 0x10
-#define XFS_BLI_CHUNK 128
-#define XFS_BLI_SHIFT 7
+#define XFS_BLF_CHUNK 128
+#define XFS_BLF_SHIFT 7
#define BIT_TO_WORD_SHIFT 5
#define NBWORD (NBBY * sizeof(unsigned int))
@@ -69,6 +69,7 @@ typedef struct xfs_buf_log_format {
#define XFS_BLI_LOGGED 0x08
#define XFS_BLI_INODE_ALLOC_BUF 0x10
#define XFS_BLI_STALE_INODE 0x20
+#define XFS_BLI_INODE_BUF 0x40
#define XFS_BLI_FLAGS \
{ XFS_BLI_HOLD, "HOLD" }, \
@@ -76,7 +77,8 @@ typedef struct xfs_buf_log_format {
{ XFS_BLI_STALE, "STALE" }, \
{ XFS_BLI_LOGGED, "LOGGED" }, \
{ XFS_BLI_INODE_ALLOC_BUF, "INODE_ALLOC" }, \
- { XFS_BLI_STALE_INODE, "STALE_INODE" }
+ { XFS_BLI_STALE_INODE, "STALE_INODE" }, \
+ { XFS_BLI_INODE_BUF, "INODE_BUF" }
#ifdef __KERNEL__
diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c
index ef96175..047b8a8 100644
--- a/fs/xfs/xfs_error.c
+++ b/fs/xfs/xfs_error.c
@@ -170,7 +170,7 @@ xfs_cmn_err(int panic_tag, int level, xfs_mount_t *mp, char *fmt, ...)
va_list ap;
#ifdef DEBUG
- xfs_panic_mask |= XFS_PTAG_SHUTDOWN_CORRUPT;
+ xfs_panic_mask |= (XFS_PTAG_SHUTDOWN_CORRUPT | XFS_PTAG_LOGRES);
#endif
if (xfs_panic_mask && (xfs_panic_mask & panic_tag)
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 3038dd5..5215abc 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -54,9 +54,6 @@ STATIC xlog_t * xlog_alloc_log(xfs_mount_t *mp,
STATIC int xlog_space_left(xlog_t *log, int cycle, int bytes);
STATIC int xlog_sync(xlog_t *log, xlog_in_core_t *iclog);
STATIC void xlog_dealloc_log(xlog_t *log);
-STATIC int xlog_write(struct log *log, struct xfs_log_vec *log_vector,
- struct xlog_ticket *tic, xfs_lsn_t *start_lsn,
- xlog_in_core_t **commit_iclog, uint flags);
/* local state machine functions */
STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
@@ -86,14 +83,6 @@ STATIC int xlog_regrant_write_log_space(xlog_t *log,
STATIC void xlog_ungrant_log_space(xlog_t *log,
xlog_ticket_t *ticket);
-
-/* local ticket functions */
-STATIC xlog_ticket_t *xlog_ticket_alloc(xlog_t *log,
- int unit_bytes,
- int count,
- char clientid,
- uint flags);
-
#if defined(DEBUG)
STATIC void xlog_verify_dest_ptr(xlog_t *log, char *ptr);
STATIC void xlog_verify_grant_head(xlog_t *log, int equals);
@@ -360,6 +349,15 @@ xfs_log_reserve(
ASSERT(flags & XFS_LOG_PERM_RESERV);
internal_ticket = *ticket;
+ /*
+ * this is a new transaction on the ticket, so we need to
+ * change the transaction ID so that the next transaction has a
+ * different TID in the log. Just add one to the existing tid
+ * so that we can see chains of rolling transactions in the log
+ * easily.
+ */
+ internal_ticket->t_tid++;
+
trace_xfs_log_reserve(log, internal_ticket);
xlog_grant_push_ail(mp, internal_ticket->t_unit_res);
@@ -367,7 +365,8 @@ xfs_log_reserve(
} else {
/* may sleep if need to allocate more tickets */
internal_ticket = xlog_ticket_alloc(log, unit_bytes, cnt,
- client, flags);
+ client, flags,
+ KM_SLEEP|KM_MAYFAIL);
if (!internal_ticket)
return XFS_ERROR(ENOMEM);
internal_ticket->t_trans_type = t_type;
@@ -452,6 +451,13 @@ xfs_log_mount(
/* Normal transactions can now occur */
mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
+ /*
+ * Now the log has been fully initialised and we know were our
+ * space grant counters are, we can initialise the permanent ticket
+ * needed for delayed logging to work.
+ */
+ xlog_cil_init_post_recovery(mp->m_log);
+
return 0;
out_destroy_ail:
@@ -658,6 +664,10 @@ xfs_log_item_init(
item->li_ailp = mp->m_ail;
item->li_type = type;
item->li_ops = ops;
+ item->li_lv = NULL;
+
+ INIT_LIST_HEAD(&item->li_ail);
+ INIT_LIST_HEAD(&item->li_cil);
}
/*
@@ -1168,6 +1178,9 @@ xlog_alloc_log(xfs_mount_t *mp,
*iclogp = log->l_iclog; /* complete ring */
log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
+ error = xlog_cil_init(log);
+ if (error)
+ goto out_free_iclog;
return log;
out_free_iclog:
@@ -1494,6 +1507,8 @@ xlog_dealloc_log(xlog_t *log)
xlog_in_core_t *iclog, *next_iclog;
int i;
+ xlog_cil_destroy(log);
+
iclog = log->l_iclog;
for (i=0; i<log->l_iclog_bufs; i++) {
sv_destroy(&iclog->ic_force_wait);
@@ -1536,8 +1551,10 @@ xlog_state_finish_copy(xlog_t *log,
* print out info relating to regions written which consume
* the reservation
*/
-STATIC void
-xlog_print_tic_res(xfs_mount_t *mp, xlog_ticket_t *ticket)
+void
+xlog_print_tic_res(
+ struct xfs_mount *mp,
+ struct xlog_ticket *ticket)
{
uint i;
uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
@@ -1637,6 +1654,10 @@ xlog_print_tic_res(xfs_mount_t *mp, xlog_ticket_t *ticket)
"bad-rtype" : res_type_str[r_type-1]),
ticket->t_res_arr[i].r_len);
}
+
+ xfs_cmn_err(XFS_PTAG_LOGRES, CE_ALERT, mp,
+ "xfs_log_write: reservation ran out. Need to up reservation");
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
}
/*
@@ -1865,7 +1886,7 @@ xlog_write_copy_finish(
* we don't update ic_offset until the end when we know exactly how many
* bytes have been written out.
*/
-STATIC int
+int
xlog_write(
struct log *log,
struct xfs_log_vec *log_vector,
@@ -1889,22 +1910,26 @@ xlog_write(
*start_lsn = 0;
len = xlog_write_calc_vec_length(ticket, log_vector);
- if (ticket->t_curr_res < len) {
- xlog_print_tic_res(log->l_mp, ticket);
-#ifdef DEBUG
- xlog_panic(
- "xfs_log_write: reservation ran out. Need to up reservation");
-#else
- /* Customer configurable panic */
- xfs_cmn_err(XFS_PTAG_LOGRES, CE_ALERT, log->l_mp,
- "xfs_log_write: reservation ran out. Need to up reservation");
+ if (log->l_cilp) {
+ /*
+ * Region headers and bytes are already accounted for.
+ * We only need to take into account start records and
+ * split regions in this function.
+ */
+ if (ticket->t_flags & XLOG_TIC_INITED)
+ ticket->t_curr_res -= sizeof(xlog_op_header_t);
- /* If we did not panic, shutdown the filesystem */
- xfs_force_shutdown(log->l_mp, SHUTDOWN_CORRUPT_INCORE);
-#endif
- }
+ /*
+ * Commit record headers need to be accounted for. These
+ * come in as separate writes so are easy to detect.
+ */
+ if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))
+ ticket->t_curr_res -= sizeof(xlog_op_header_t);
+ } else
+ ticket->t_curr_res -= len;
- ticket->t_curr_res -= len;
+ if (ticket->t_curr_res < 0)
+ xlog_print_tic_res(log->l_mp, ticket);
index = 0;
lv = log_vector;
@@ -3000,6 +3025,8 @@ _xfs_log_force(
XFS_STATS_INC(xs_log_force);
+ xlog_cil_push(log, 1);
+
spin_lock(&log->l_icloglock);
iclog = log->l_iclog;
@@ -3149,6 +3176,12 @@ _xfs_log_force_lsn(
XFS_STATS_INC(xs_log_force);
+ if (log->l_cilp) {
+ lsn = xlog_cil_push_lsn(log, lsn);
+ if (lsn == NULLCOMMITLSN)
+ return 0;
+ }
+
try_again:
spin_lock(&log->l_icloglock);
iclog = log->l_iclog;
@@ -3313,22 +3346,30 @@ xfs_log_ticket_get(
return ticket;
}
+xlog_tid_t
+xfs_log_get_trans_ident(
+ struct xfs_trans *tp)
+{
+ return tp->t_ticket->t_tid;
+}
+
/*
* Allocate and initialise a new log ticket.
*/
-STATIC xlog_ticket_t *
+xlog_ticket_t *
xlog_ticket_alloc(
struct log *log,
int unit_bytes,
int cnt,
char client,
- uint xflags)
+ uint xflags,
+ int alloc_flags)
{
struct xlog_ticket *tic;
uint num_headers;
int iclog_space;
- tic = kmem_zone_zalloc(xfs_log_ticket_zone, KM_SLEEP|KM_MAYFAIL);
+ tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
if (!tic)
return NULL;
@@ -3647,6 +3688,11 @@ xlog_state_ioerror(
* c. nothing new gets queued up after (a) and (b) are done.
* d. if !logerror, flush the iclogs to disk, then seal them off
* for business.
+ *
+ * Note: for delayed logging the !logerror case needs to flush the regions
+ * held in memory out to the iclogs before flushing them to disk. This needs
+ * to be done before the log is marked as shutdown, otherwise the flush to the
+ * iclogs will fail.
*/
int
xfs_log_force_umount(
@@ -3680,6 +3726,16 @@ xfs_log_force_umount(
return 1;
}
retval = 0;
+
+ /*
+ * Flush the in memory commit item list before marking the log as
+ * being shut down. We need to do it in this order to ensure all the
+ * completed transactions are flushed to disk with the xfs_log_force()
+ * call below.
+ */
+ if (!logerror && (mp->m_flags & XFS_MOUNT_DELAYLOG))
+ xlog_cil_push(log, 1);
+
/*
* We must hold both the GRANT lock and the LOG lock,
* before we mark the filesystem SHUTDOWN and wake
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index 229d1f3..04c78e6 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -19,7 +19,6 @@
#define __XFS_LOG_H__
/* get lsn fields */
-
#define CYCLE_LSN(lsn) ((uint)((lsn)>>32))
#define BLOCK_LSN(lsn) ((uint)(lsn))
@@ -114,6 +113,9 @@ struct xfs_log_vec {
struct xfs_log_vec *lv_next; /* next lv in build list */
int lv_niovecs; /* number of iovecs in lv */
struct xfs_log_iovec *lv_iovecp; /* iovec array */
+ struct xfs_log_item *lv_item; /* owner */
+ char *lv_buf; /* formatted buffer */
+ int lv_buf_len; /* size of formatted buffer */
};
/*
@@ -134,6 +136,7 @@ struct xlog_in_core;
struct xlog_ticket;
struct xfs_log_item;
struct xfs_item_ops;
+struct xfs_trans;
void xfs_log_item_init(struct xfs_mount *mp,
struct xfs_log_item *item,
@@ -187,9 +190,16 @@ int xfs_log_need_covered(struct xfs_mount *mp);
void xlog_iodone(struct xfs_buf *);
-struct xlog_ticket * xfs_log_ticket_get(struct xlog_ticket *ticket);
+struct xlog_ticket *xfs_log_ticket_get(struct xlog_ticket *ticket);
void xfs_log_ticket_put(struct xlog_ticket *ticket);
+xlog_tid_t xfs_log_get_trans_ident(struct xfs_trans *tp);
+
+int xfs_log_commit_cil(struct xfs_mount *mp, struct xfs_trans *tp,
+ struct xfs_log_vec *log_vector,
+ xfs_lsn_t *commit_lsn, int flags);
+bool xfs_log_item_in_current_chkpt(struct xfs_log_item *lip);
+
#endif
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
new file mode 100644
index 0000000..bb17cc0
--- /dev/null
+++ b/fs/xfs/xfs_log_cil.c
@@ -0,0 +1,725 @@
+/*
+ * Copyright (c) 2010 Red Hat, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_types.h"
+#include "xfs_bit.h"
+#include "xfs_log.h"
+#include "xfs_inum.h"
+#include "xfs_trans.h"
+#include "xfs_trans_priv.h"
+#include "xfs_log_priv.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_dir2.h"
+#include "xfs_dmapi.h"
+#include "xfs_mount.h"
+#include "xfs_error.h"
+#include "xfs_alloc.h"
+
+/*
+ * Perform initial CIL structure initialisation. If the CIL is not
+ * enabled in this filesystem, ensure the log->l_cilp is null so
+ * we can check this conditional to determine if we are doing delayed
+ * logging or not.
+ */
+int
+xlog_cil_init(
+ struct log *log)
+{
+ struct xfs_cil *cil;
+ struct xfs_cil_ctx *ctx;
+
+ log->l_cilp = NULL;
+ if (!(log->l_mp->m_flags & XFS_MOUNT_DELAYLOG))
+ return 0;
+
+ cil = kmem_zalloc(sizeof(*cil), KM_SLEEP|KM_MAYFAIL);
+ if (!cil)
+ return ENOMEM;
+
+ ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP|KM_MAYFAIL);
+ if (!ctx) {
+ kmem_free(cil);
+ return ENOMEM;
+ }
+
+ INIT_LIST_HEAD(&cil->xc_cil);
+ INIT_LIST_HEAD(&cil->xc_committing);
+ spin_lock_init(&cil->xc_cil_lock);
+ init_rwsem(&cil->xc_ctx_lock);
+ sv_init(&cil->xc_commit_wait, SV_DEFAULT, "cilwait");
+
+ INIT_LIST_HEAD(&ctx->committing);
+ INIT_LIST_HEAD(&ctx->busy_extents);
+ ctx->sequence = 1;
+ ctx->cil = cil;
+ cil->xc_ctx = ctx;
+
+ cil->xc_log = log;
+ log->l_cilp = cil;
+ return 0;
+}
+
+void
+xlog_cil_destroy(
+ struct log *log)
+{
+ if (!log->l_cilp)
+ return;
+
+ if (log->l_cilp->xc_ctx) {
+ if (log->l_cilp->xc_ctx->ticket)
+ xfs_log_ticket_put(log->l_cilp->xc_ctx->ticket);
+ kmem_free(log->l_cilp->xc_ctx);
+ }
+
+ ASSERT(list_empty(&log->l_cilp->xc_cil));
+ kmem_free(log->l_cilp);
+}
+
+/*
+ * Allocate a new ticket. Failing to get a new ticket makes it really hard to
+ * recover, so we don't allow failure here. Also, we allocate in a context that
+ * we don't want to be issuing transactions from, so we need to tell the
+ * allocation code this as well.
+ *
+ * We don't reserve any space for the ticket - we are going to steal whatever
+ * space we require from transactions as they commit. To ensure we reserve all
+ * the space required, we need to set the current reservation of the ticket to
+ * zero so that we know to steal the initial transaction overhead from the
+ * first transaction commit.
+ */
+static struct xlog_ticket *
+xlog_cil_ticket_alloc(
+ struct log *log)
+{
+ struct xlog_ticket *tic;
+
+ tic = xlog_ticket_alloc(log, 0, 1, XFS_TRANSACTION, 0,
+ KM_SLEEP|KM_NOFS);
+ tic->t_trans_type = XFS_TRANS_CHECKPOINT;
+
+ /*
+ * set the current reservation to zero so we know to steal the basic
+ * transaction overhead reservation from the first transaction commit.
+ */
+ tic->t_curr_res = 0;
+ return tic;
+}
+
+/*
+ * After the first stage of log recovery is done, we know where the head and
+ * tail of the log are. We need this log initialisation done before we can
+ * initialise the first CIL checkpoint context.
+ *
+ * Here we allocate a log ticket to track space usage during a CIL push. This
+ * ticket is passed to xlog_write() directly so that we don't slowly leak log
+ * space by failing to account for space used by log headers and additional
+ * region headers for split regions.
+ */
+void
+xlog_cil_init_post_recovery(
+ struct log *log)
+{
+ if (!log->l_cilp)
+ return;
+
+ log->l_cilp->xc_ctx->ticket = xlog_cil_ticket_alloc(log);
+ log->l_cilp->xc_ctx->sequence = 1;
+ log->l_cilp->xc_ctx->commit_lsn = xlog_assign_lsn(log->l_curr_cycle,
+ log->l_curr_block);
+}
+
+/*
+ * Insert the log item into the CIL and calculate the difference in space
+ * consumed by the item. Add the space to the checkpoint ticket and calculate
+ * if the change requires additional log metadata. If it does, take that space
+ * as well. Remove the amount of space we addded to the checkpoint ticket from
+ * the current transaction ticket so that the accounting works out correctly.
+ *
+ * If this is the first time the item is being placed into the CIL in this
+ * context, pin it so it can't be written to disk until the CIL is flushed to
+ * the iclog and the iclog written to disk.
+ */
+static void
+xlog_cil_insert(
+ struct log *log,
+ struct xlog_ticket *ticket,
+ struct xfs_log_item *item,
+ struct xfs_log_vec *lv)
+{
+ struct xfs_cil *cil = log->l_cilp;
+ struct xfs_log_vec *old = lv->lv_item->li_lv;
+ struct xfs_cil_ctx *ctx = cil->xc_ctx;
+ int len;
+ int diff_iovecs;
+ int iclog_space;
+
+ if (old) {
+ /* existing lv on log item, space used is a delta */
+ ASSERT(!list_empty(&item->li_cil));
+ ASSERT(old->lv_buf && old->lv_buf_len && old->lv_niovecs);
+
+ len = lv->lv_buf_len - old->lv_buf_len;
+ diff_iovecs = lv->lv_niovecs - old->lv_niovecs;
+ kmem_free(old->lv_buf);
+ kmem_free(old);
+ } else {
+ /* new lv, must pin the log item */
+ ASSERT(!lv->lv_item->li_lv);
+ ASSERT(list_empty(&item->li_cil));
+
+ len = lv->lv_buf_len;
+ diff_iovecs = lv->lv_niovecs;
+ IOP_PIN(lv->lv_item);
+
+ }
+ len += diff_iovecs * sizeof(xlog_op_header_t);
+
+ /* attach new log vector to log item */
+ lv->lv_item->li_lv = lv;
+
+ spin_lock(&cil->xc_cil_lock);
+ list_move_tail(&item->li_cil, &cil->xc_cil);
+ ctx->nvecs += diff_iovecs;
+
+ /*
+ * If this is the first time the item is being committed to the CIL,
+ * store the sequence number on the log item so we can tell
+ * in future commits whether this is the first checkpoint the item is
+ * being committed into.
+ */
+ if (!item->li_seq)
+ item->li_seq = ctx->sequence;
+
+ /*
+ * Now transfer enough transaction reservation to the context ticket
+ * for the checkpoint. The context ticket is special - the unit
+ * reservation has to grow as well as the current reservation as we
+ * steal from tickets so we can correctly determine the space used
+ * during the transaction commit.
+ */
+ if (ctx->ticket->t_curr_res == 0) {
+ /* first commit in checkpoint, steal the header reservation */
+ ASSERT(ticket->t_curr_res >= ctx->ticket->t_unit_res + len);
+ ctx->ticket->t_curr_res = ctx->ticket->t_unit_res;
+ ticket->t_curr_res -= ctx->ticket->t_unit_res;
+ }
+
+ /* do we need space for more log record headers? */
+ iclog_space = log->l_iclog_size - log->l_iclog_hsize;
+ if (len > 0 && (ctx->space_used / iclog_space !=
+ (ctx->space_used + len) / iclog_space)) {
+ int hdrs;
+
+ hdrs = (len + iclog_space - 1) / iclog_space;
+ /* need to take into account split region headers, too */
+ hdrs *= log->l_iclog_hsize + sizeof(struct xlog_op_header);
+ ctx->ticket->t_unit_res += hdrs;
+ ctx->ticket->t_curr_res += hdrs;
+ ticket->t_curr_res -= hdrs;
+ ASSERT(ticket->t_curr_res >= len);
+ }
+ ticket->t_curr_res -= len;
+ ctx->space_used += len;
+
+ spin_unlock(&cil->xc_cil_lock);
+}
+
+/*
+ * Format log item into a flat buffers
+ *
+ * For delayed logging, we need to hold a formatted buffer containing all the
+ * changes on the log item. This enables us to relog the item in memory and
+ * write it out asynchronously without needing to relock the object that was
+ * modified at the time it gets written into the iclog.
+ *
+ * This function builds a vector for the changes in each log item in the
+ * transaction. It then works out the length of the buffer needed for each log
+ * item, allocates them and formats the vector for the item into the buffer.
+ * The buffer is then attached to the log item are then inserted into the
+ * Committed Item List for tracking until the next checkpoint is written out.
+ *
+ * We don't set up region headers during this process; we simply copy the
+ * regions into the flat buffer. We can do this because we still have to do a
+ * formatting step to write the regions into the iclog buffer. Writing the
+ * ophdrs during the iclog write means that we can support splitting large
+ * regions across iclog boundares without needing a change in the format of the
+ * item/region encapsulation.
+ *
+ * Hence what we need to do now is change the rewrite the vector array to point
+ * to the copied region inside the buffer we just allocated. This allows us to
+ * format the regions into the iclog as though they are being formatted
+ * directly out of the objects themselves.
+ */
+static void
+xlog_cil_format_items(
+ struct log *log,
+ struct xfs_log_vec *log_vector,
+ struct xlog_ticket *ticket,
+ xfs_lsn_t *start_lsn)
+{
+ struct xfs_log_vec *lv;
+
+ if (start_lsn)
+ *start_lsn = log->l_cilp->xc_ctx->sequence;
+
+ ASSERT(log_vector);
+ for (lv = log_vector; lv; lv = lv->lv_next) {
+ void *ptr;
+ int index;
+ int len = 0;
+
+ /* build the vector array and calculate it's length */
+ IOP_FORMAT(lv->lv_item, lv->lv_iovecp);
+ for (index = 0; index < lv->lv_niovecs; index++)
+ len += lv->lv_iovecp[index].i_len;
+
+ lv->lv_buf_len = len;
+ lv->lv_buf = kmem_zalloc(lv->lv_buf_len, KM_SLEEP|KM_NOFS);
+ ptr = lv->lv_buf;
+
+ for (index = 0; index < lv->lv_niovecs; index++) {
+ struct xfs_log_iovec *vec = &lv->lv_iovecp[index];
+
+ memcpy(ptr, vec->i_addr, vec->i_len);
+ vec->i_addr = ptr;
+ ptr += vec->i_len;
+ }
+ ASSERT(ptr == lv->lv_buf + lv->lv_buf_len);
+
+ xlog_cil_insert(log, ticket, lv->lv_item, lv);
+ }
+}
+
+static void
+xlog_cil_free_logvec(
+ struct xfs_log_vec *log_vector)
+{
+ struct xfs_log_vec *lv;
+
+ for (lv = log_vector; lv; ) {
+ struct xfs_log_vec *next = lv->lv_next;
+ kmem_free(lv->lv_buf);
+ kmem_free(lv);
+ lv = next;
+ }
+}
+
+/*
+ * Commit a transaction with the given vector to the Committed Item List.
+ *
+ * To do this, we need to format the item, pin it in memory if required and
+ * account for the space used by the transaction. Once we have done that we
+ * need to release the unused reservation for the transaction, attach the
+ * transaction to the checkpoint context so we carry the busy extents through
+ * to checkpoint completion, and then unlock all the items in the transaction.
+ *
+ * For more specific information about the order of operations in
+ * xfs_log_commit_cil() please refer to the comments in
+ * xfs_trans_commit_iclog().
+ *
+ * Called with the context lock already held in read mode to lock out
+ * background commit, returns without it held once background commits are
+ * allowed again.
+ */
+int
+xfs_log_commit_cil(
+ struct xfs_mount *mp,
+ struct xfs_trans *tp,
+ struct xfs_log_vec *log_vector,
+ xfs_lsn_t *commit_lsn,
+ int flags)
+{
+ struct log *log = mp->m_log;
+ int log_flags = 0;
+ int push = 0;
+
+ if (flags & XFS_TRANS_RELEASE_LOG_RES)
+ log_flags = XFS_LOG_REL_PERM_RESERV;
+
+ if (XLOG_FORCED_SHUTDOWN(log)) {
+ xlog_cil_free_logvec(log_vector);
+ return XFS_ERROR(EIO);
+ }
+
+ /* lock out background commit */
+ down_read(&log->l_cilp->xc_ctx_lock);
+ xlog_cil_format_items(log, log_vector, tp->t_ticket, commit_lsn);
+
+ /* check we didn't blow the reservation */
+ if (tp->t_ticket->t_curr_res < 0)
+ xlog_print_tic_res(log->l_mp, tp->t_ticket);
+
+ /* attach the transaction to the CIL if it has any busy extents */
+ if (!list_empty(&tp->t_busy)) {
+ spin_lock(&log->l_cilp->xc_cil_lock);
+ list_splice_init(&tp->t_busy,
+ &log->l_cilp->xc_ctx->busy_extents);
+ spin_unlock(&log->l_cilp->xc_cil_lock);
+ }
+
+ tp->t_commit_lsn = *commit_lsn;
+ xfs_log_done(mp, tp->t_ticket, NULL, log_flags);
+ xfs_trans_unreserve_and_mod_sb(tp);
+
+ /* check for background commit before unlock */
+ if (log->l_cilp->xc_ctx->space_used > XLOG_CIL_SPACE_LIMIT(log))
+ push = 1;
+ up_read(&log->l_cilp->xc_ctx_lock);
+
+ /*
+ * We need to push CIL every so often so we don't cache more than we
+ * can fit in the log. The limit really is that a checkpoint can't be
+ * more than half the log (the current checkpoint is not allowed to
+ * overwrite the previous checkpoint), but commit latency and memory
+ * usage limit this to a smaller size in most cases.
+ */
+ if (push)
+ xlog_cil_push(log, 0);
+ return 0;
+}
+
+/*
+ * Mark all items committed and clear busy extents. We free the log vector
+ * chains in a separate pass so that we unpin the log items as quickly as
+ * possible.
+ */
+static void
+xlog_cil_committed(
+ void *args,
+ int abort)
+{
+ struct xfs_cil_ctx *ctx = args;
+ struct xfs_log_vec *lv;
+ int abortflag = abort ? XFS_LI_ABORTED : 0;
+ struct xfs_busy_extent *busyp, *n;
+
+ /* unpin all the log items */
+ for (lv = ctx->lv_chain; lv; lv = lv->lv_next ) {
+ xfs_trans_item_committed(lv->lv_item, ctx->start_lsn,
+ abortflag);
+ }
+
+ list_for_each_entry_safe(busyp, n, &ctx->busy_extents, list)
+ xfs_alloc_busy_clear(ctx->cil->xc_log->l_mp, busyp);
+
+ spin_lock(&ctx->cil->xc_cil_lock);
+ list_del(&ctx->committing);
+ spin_unlock(&ctx->cil->xc_cil_lock);
+
+ xlog_cil_free_logvec(ctx->lv_chain);
+ kmem_free(ctx);
+}
+
+/*
+ * Push the Committed Item List to the log. If the push_now flag is not set,
+ * then it is a background flush and so we can chose to ignore it.
+ */
+int
+xlog_cil_push(
+ struct log *log,
+ int push_now)
+{
+ struct xfs_cil *cil = log->l_cilp;
+ struct xfs_log_vec *lv;
+ struct xfs_cil_ctx *ctx;
+ struct xfs_cil_ctx *new_ctx;
+ struct xlog_in_core *commit_iclog;
+ struct xlog_ticket *tic;
+ int num_lv;
+ int num_iovecs;
+ int len;
+ int error = 0;
+ struct xfs_trans_header thdr;
+ struct xfs_log_iovec lhdr;
+ struct xfs_log_vec lvhdr = { NULL };
+ xfs_lsn_t commit_lsn;
+
+ if (!cil)
+ return 0;
+
+ new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_SLEEP|KM_NOFS);
+ new_ctx->ticket = xlog_cil_ticket_alloc(log);
+
+ /* lock out transaction commit, but don't block on background push */
+ if (!down_write_trylock(&cil->xc_ctx_lock)) {
+ if (!push_now)
+ goto out_free_ticket;
+ down_write(&cil->xc_ctx_lock);
+ }
+ ctx = cil->xc_ctx;
+
+ /* check if we've anything to push */
+ if (list_empty(&cil->xc_cil))
+ goto out_skip;
+
+ /* check for spurious background flush */
+ if (!push_now && cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log))
+ goto out_skip;
+
+ /*
+ * pull all the log vectors off the items in the CIL, and
+ * remove the items from the CIL. We don't need the CIL lock
+ * here because it's only needed on the transaction commit
+ * side which is currently locked out by the flush lock.
+ */
+ lv = NULL;
+ num_lv = 0;
+ num_iovecs = 0;
+ len = 0;
+ while (!list_empty(&cil->xc_cil)) {
+ struct xfs_log_item *item;
+ int i;
+
+ item = list_first_entry(&cil->xc_cil,
+ struct xfs_log_item, li_cil);
+ list_del_init(&item->li_cil);
+ if (!ctx->lv_chain)
+ ctx->lv_chain = item->li_lv;
+ else
+ lv->lv_next = item->li_lv;
+ lv = item->li_lv;
+ item->li_lv = NULL;
+
+ num_lv++;
+ num_iovecs += lv->lv_niovecs;
+ for (i = 0; i < lv->lv_niovecs; i++)
+ len += lv->lv_iovecp[i].i_len;
+ }
+
+ /*
+ * initialise the new context and attach it to the CIL. Then attach
+ * the current context to the CIL committing lsit so it can be found
+ * during log forces to extract the commit lsn of the sequence that
+ * needs to be forced.
+ */
+ INIT_LIST_HEAD(&new_ctx->committing);
+ INIT_LIST_HEAD(&new_ctx->busy_extents);
+ new_ctx->sequence = ctx->sequence + 1;
+ new_ctx->cil = cil;
+ cil->xc_ctx = new_ctx;
+
+ /*
+ * The switch is now done, so we can drop the context lock and move out
+ * of a shared context. We can't just go straight to the commit record,
+ * though - we need to synchronise with previous and future commits so
+ * that the commit records are correctly ordered in the log to ensure
+ * that we process items during log IO completion in the correct order.
+ *
+ * For example, if we get an EFI in one checkpoint and the EFD in the
+ * next (e.g. due to log forces), we do not want the checkpoint with
+ * the EFD to be committed before the checkpoint with the EFI. Hence
+ * we must strictly order the commit records of the checkpoints so
+ * that: a) the checkpoint callbacks are attached to the iclogs in the
+ * correct order; and b) the checkpoints are replayed in correct order
+ * in log recovery.
+ *
+ * Hence we need to add this context to the committing context list so
+ * that higher sequences will wait for us to write out a commit record
+ * before they do.
+ */
+ spin_lock(&cil->xc_cil_lock);
+ list_add(&ctx->committing, &cil->xc_committing);
+ spin_unlock(&cil->xc_cil_lock);
+ up_write(&cil->xc_ctx_lock);
+
+ /*
+ * Build a checkpoint transaction header and write it to the log to
+ * begin the transaction. We need to account for the space used by the
+ * transaction header here as it is not accounted for in xlog_write().
+ *
+ * The LSN we need to pass to the log items on transaction commit is
+ * the LSN reported by the first log vector write. If we use the commit
+ * record lsn then we can move the tail beyond the grant write head.
+ */
+ tic = ctx->ticket;
+ thdr.th_magic = XFS_TRANS_HEADER_MAGIC;
+ thdr.th_type = XFS_TRANS_CHECKPOINT;
+ thdr.th_tid = tic->t_tid;
+ thdr.th_num_items = num_iovecs;
+ lhdr.i_addr = (xfs_caddr_t)&thdr;
+ lhdr.i_len = sizeof(xfs_trans_header_t);
+ lhdr.i_type = XLOG_REG_TYPE_TRANSHDR;
+ tic->t_curr_res -= lhdr.i_len + sizeof(xlog_op_header_t);
+
+ lvhdr.lv_niovecs = 1;
+ lvhdr.lv_iovecp = &lhdr;
+ lvhdr.lv_next = ctx->lv_chain;
+
+ error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL, 0);
+ if (error)
+ goto out_abort;
+
+ /*
+ * now that we've written the checkpoint into the log, strictly
+ * order the commit records so replay will get them in the right order.
+ */
+restart:
+ spin_lock(&cil->xc_cil_lock);
+ list_for_each_entry(new_ctx, &cil->xc_committing, committing) {
+ /*
+ * Higher sequences will wait for this one so skip them.
+ * Don't wait for own own sequence, either.
+ */
+ if (new_ctx->sequence >= ctx->sequence)
+ continue;
+ if (!new_ctx->commit_lsn) {
+ /*
+ * It is still being pushed! Wait for the push to
+ * complete, then start again from the beginning.
+ */
+ sv_wait(&cil->xc_commit_wait, 0, &cil->xc_cil_lock, 0);
+ goto restart;
+ }
+ }
+ spin_unlock(&cil->xc_cil_lock);
+
+ commit_lsn = xfs_log_done(log->l_mp, tic, &commit_iclog, 0);
+ if (error || commit_lsn == -1)
+ goto out_abort;
+
+ /* attach all the transactions w/ busy extents to iclog */
+ ctx->log_cb.cb_func = xlog_cil_committed;
+ ctx->log_cb.cb_arg = ctx;
+ error = xfs_log_notify(log->l_mp, commit_iclog, &ctx->log_cb);
+ if (error)
+ goto out_abort;
+
+ /*
+ * now the checkpoint commit is complete and we've attached the
+ * callbacks to the iclog we can assign the commit LSN to the context
+ * and wake up anyone who is waiting for the commit to complete.
+ */
+ spin_lock(&cil->xc_cil_lock);
+ ctx->commit_lsn = commit_lsn;
+ sv_broadcast(&cil->xc_commit_wait);
+ spin_unlock(&cil->xc_cil_lock);
+
+ /* release the hounds! */
+ return xfs_log_release_iclog(log->l_mp, commit_iclog);
+
+out_skip:
+ up_write(&cil->xc_ctx_lock);
+out_free_ticket:
+ xfs_log_ticket_put(new_ctx->ticket);
+ kmem_free(new_ctx);
+ return 0;
+
+out_abort:
+ xlog_cil_committed(ctx, XFS_LI_ABORTED);
+ return XFS_ERROR(EIO);
+}
+
+/*
+ * Conditionally push the CIL based on the sequence passed in.
+ *
+ * We only need to push if we haven't already pushed the sequence
+ * number given. Hence the only time we will trigger a push here is
+ * if the push sequence is the same as the current context.
+ *
+ * We return the current commit lsn to allow the callers to determine if a
+ * iclog flush is necessary following this call.
+ *
+ * XXX: Initially, just push the CIL unconditionally and return whatever
+ * commit lsn is there. It'll be empty, so this is broken for now.
+ */
+xfs_lsn_t
+xlog_cil_push_lsn(
+ struct log *log,
+ xfs_lsn_t push_seq)
+{
+ struct xfs_cil *cil = log->l_cilp;
+ struct xfs_cil_ctx *ctx;
+ xfs_lsn_t commit_lsn = NULLCOMMITLSN;
+
+restart:
+ down_write(&cil->xc_ctx_lock);
+ ASSERT(push_seq <= cil->xc_ctx->sequence);
+
+ /* check to see if we need to force out the current context */
+ if (push_seq == cil->xc_ctx->sequence) {
+ up_write(&cil->xc_ctx_lock);
+ xlog_cil_push(log, 1);
+ goto restart;
+ }
+
+ /*
+ * See if we can find a previous sequence still committing.
+ * We can drop the flush lock as soon as we have the cil lock
+ * because we are now only comparing contexts protected by
+ * the cil lock.
+ *
+ * We need to wait for all previous sequence commits to complete
+ * before allowing the force of push_seq to go ahead. Hence block
+ * on commits for those as well.
+ */
+ spin_lock(&cil->xc_cil_lock);
+ up_write(&cil->xc_ctx_lock);
+ list_for_each_entry(ctx, &cil->xc_committing, committing) {
+ if (ctx->sequence > push_seq)
+ continue;
+ if (!ctx->commit_lsn) {
+ /*
+ * It is still being pushed! Wait for the push to
+ * complete, then start again from the beginning.
+ */
+ sv_wait(&cil->xc_commit_wait, 0, &cil->xc_cil_lock, 0);
+ goto restart;
+ }
+ if (ctx->sequence != push_seq)
+ continue;
+ /* found it! */
+ commit_lsn = ctx->commit_lsn;
+ }
+ spin_unlock(&cil->xc_cil_lock);
+ return commit_lsn;
+}
+
+/*
+ * Check if the current log item was first committed in this sequence.
+ * We can't rely on just the log item being in the CIL, we have to check
+ * the recorded commit sequence number.
+ *
+ * Note: for this to be used in a non-racy manner, it has to be called with
+ * CIL flushing locked out. As a result, it should only be used during the
+ * transaction commit process when deciding what to format into the item.
+ */
+bool
+xfs_log_item_in_current_chkpt(
+ struct xfs_log_item *lip)
+{
+ struct xfs_cil_ctx *ctx;
+
+ if (!(lip->li_mountp->m_flags & XFS_MOUNT_DELAYLOG))
+ return false;
+ if (list_empty(&lip->li_cil))
+ return false;
+
+ ctx = lip->li_mountp->m_log->l_cilp->xc_ctx;
+
+ /*
+ * li_seq is written on the first commit of a log item to record the
+ * first checkpoint it is written to. Hence if it is different to the
+ * current sequence, we're in a new checkpoint.
+ */
+ if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0)
+ return false;
+ return true;
+}
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 9cf6951..8c07261 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -152,8 +152,6 @@ static inline uint xlog_get_client_id(__be32 i)
#define XLOG_RECOVERY_NEEDED 0x4 /* log was recovered */
#define XLOG_IO_ERROR 0x8 /* log hit an I/O error, and being
shutdown */
-typedef __uint32_t xlog_tid_t;
-
#ifdef __KERNEL__
/*
@@ -379,6 +377,99 @@ typedef struct xlog_in_core {
} xlog_in_core_t;
/*
+ * The CIL context is used to aggregate per-transaction details as well be
+ * passed to the iclog for checkpoint post-commit processing. After being
+ * passed to the iclog, another context needs to be allocated for tracking the
+ * next set of transactions to be aggregated into a checkpoint.
+ */
+struct xfs_cil;
+
+struct xfs_cil_ctx {
+ struct xfs_cil *cil;
+ xfs_lsn_t sequence; /* chkpt sequence # */
+ xfs_lsn_t start_lsn; /* first LSN of chkpt commit */
+ xfs_lsn_t commit_lsn; /* chkpt commit record lsn */
+ struct xlog_ticket *ticket; /* chkpt ticket */
+ int nvecs; /* number of regions */
+ int space_used; /* aggregate size of regions */
+ struct list_head busy_extents; /* busy extents in chkpt */
+ struct xfs_log_vec *lv_chain; /* logvecs being pushed */
+ xfs_log_callback_t log_cb; /* completion callback hook. */
+ struct list_head committing; /* ctx committing list */
+};
+
+/*
+ * Committed Item List structure
+ *
+ * This structure is used to track log items that have been committed but not
+ * yet written into the log. It is used only when the delayed logging mount
+ * option is enabled.
+ *
+ * This structure tracks the list of committing checkpoint contexts so
+ * we can avoid the problem of having to hold out new transactions during a
+ * flush until we have a the commit record LSN of the checkpoint. We can
+ * traverse the list of committing contexts in xlog_cil_push_lsn() to find a
+ * sequence match and extract the commit LSN directly from there. If the
+ * checkpoint is still in the process of committing, we can block waiting for
+ * the commit LSN to be determined as well. This should make synchronous
+ * operations almost as efficient as the old logging methods.
+ */
+struct xfs_cil {
+ struct log *xc_log;
+ struct list_head xc_cil;
+ spinlock_t xc_cil_lock;
+ struct xfs_cil_ctx *xc_ctx;
+ struct rw_semaphore xc_ctx_lock;
+ struct list_head xc_committing;
+ sv_t xc_commit_wait;
+};
+
+/*
+ * The amount of log space we should the CIL to aggregate is difficult to size.
+ * Whatever we chose we have to make we can get a reservation for the log space
+ * effectively, that it is large enough to capture sufficient relogging to
+ * reduce log buffer IO significantly, but it is not too large for the log or
+ * induces too much latency when writing out through the iclogs. We track both
+ * space consumed and the number of vectors in the checkpoint context, so we
+ * need to decide which to use for limiting.
+ *
+ * Every log buffer we write out during a push needs a header reserved, which
+ * is at least one sector and more for v2 logs. Hence we need a reservation of
+ * at least 512 bytes per 32k of log space just for the LR headers. That means
+ * 16KB of reservation per megabyte of delayed logging space we will consume,
+ * plus various headers. The number of headers will vary based on the num of
+ * io vectors, so limiting on a specific number of vectors is going to result
+ * in transactions of varying size. IOWs, it is more consistent to track and
+ * limit space consumed in the log rather than by the number of objects being
+ * logged in order to prevent checkpoint ticket overruns.
+ *
+ * Further, use of static reservations through the log grant mechanism is
+ * problematic. It introduces a lot of complexity (e.g. reserve grant vs write
+ * grant) and a significant deadlock potential because regranting write space
+ * can block on log pushes. Hence if we have to regrant log space during a log
+ * push, we can deadlock.
+ *
+ * However, we can avoid this by use of a dynamic "reservation stealing"
+ * technique during transaction commit whereby unused reservation space in the
+ * transaction ticket is transferred to the CIL ctx commit ticket to cover the
+ * space needed by the checkpoint transaction. This means that we never need to
+ * specifically reserve space for the CIL checkpoint transaction, nor do we
+ * need to regrant space once the checkpoint completes. This also means the
+ * checkpoint transaction ticket is specific to the checkpoint context, rather
+ * than the CIL itself.
+ *
+ * With dynamic reservations, we can basically make up arbitrary limits for the
+ * checkpoint size so long as they don't violate any other size rules. Hence
+ * the initial maximum size for the checkpoint transaction will be set to a
+ * quarter of the log or 8MB, which ever is smaller. 8MB is an arbitrary limit
+ * right now based on the latency of writing out a large amount of data through
+ * the circular iclog buffers.
+ */
+
+#define XLOG_CIL_SPACE_LIMIT(log) \
+ (min((log->l_logsize >> 2), (8 * 1024 * 1024)))
+
+/*
* The reservation head lsn is not made up of a cycle number and block number.
* Instead, it uses a cycle number and byte number. Logs don't expect to
* overflow 31 bits worth of byte offset, so using a byte number will mean
@@ -388,6 +479,7 @@ typedef struct log {
/* The following fields don't need locking */
struct xfs_mount *l_mp; /* mount point */
struct xfs_ail *l_ailp; /* AIL log is working with */
+ struct xfs_cil *l_cilp; /* CIL log is working with */
struct xfs_buf *l_xbuf; /* extra buffer for log
* wrapping */
struct xfs_buftarg *l_targ; /* buftarg of log */
@@ -438,14 +530,17 @@ typedef struct log {
#define XLOG_FORCED_SHUTDOWN(log) ((log)->l_flags & XLOG_IO_ERROR)
-
/* common routines */
extern xfs_lsn_t xlog_assign_tail_lsn(struct xfs_mount *mp);
extern int xlog_recover(xlog_t *log);
extern int xlog_recover_finish(xlog_t *log);
extern void xlog_pack_data(xlog_t *log, xlog_in_core_t *iclog, int);
-extern kmem_zone_t *xfs_log_ticket_zone;
+extern kmem_zone_t *xfs_log_ticket_zone;
+struct xlog_ticket *xlog_ticket_alloc(struct log *log, int unit_bytes,
+ int count, char client, uint xflags,
+ int alloc_flags);
+
static inline void
xlog_write_adv_cnt(void **ptr, int *len, int *off, size_t bytes)
@@ -455,6 +550,21 @@ xlog_write_adv_cnt(void **ptr, int *len, int *off, size_t bytes)
*off += bytes;
}
+void xlog_print_tic_res(struct xfs_mount *mp, struct xlog_ticket *ticket);
+int xlog_write(struct log *log, struct xfs_log_vec *log_vector,
+ struct xlog_ticket *tic, xfs_lsn_t *start_lsn,
+ xlog_in_core_t **commit_iclog, uint flags);
+
+/*
+ * Committed Item List interfaces
+ */
+int xlog_cil_init(struct log *log);
+void xlog_cil_init_post_recovery(struct log *log);
+void xlog_cil_destroy(struct log *log);
+
+int xlog_cil_push(struct log *log, int push_now);
+xfs_lsn_t xlog_cil_push_lsn(struct log *log, xfs_lsn_t push_sequence);
+
/*
* Unmount record type is used as a pseudo transaction type for the ticket.
* It's value must be outside the range of XFS_TRANS_* values.
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 0de08e3..14a69ae 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -1576,7 +1576,7 @@ xlog_recover_reorder_trans(
switch (ITEM_TYPE(item)) {
case XFS_LI_BUF:
- if (!(buf_f->blf_flags & XFS_BLI_CANCEL)) {
+ if (!(buf_f->blf_flags & XFS_BLF_CANCEL)) {
trace_xfs_log_recover_item_reorder_head(log,
trans, item, pass);
list_move(&item->ri_list, &trans->r_itemq);
@@ -1638,7 +1638,7 @@ xlog_recover_do_buffer_pass1(
/*
* If this isn't a cancel buffer item, then just return.
*/
- if (!(flags & XFS_BLI_CANCEL)) {
+ if (!(flags & XFS_BLF_CANCEL)) {
trace_xfs_log_recover_buf_not_cancel(log, buf_f);
return;
}
@@ -1696,7 +1696,7 @@ xlog_recover_do_buffer_pass1(
* Check to see whether the buffer being recovered has a corresponding
* entry in the buffer cancel record table. If it does then return 1
* so that it will be cancelled, otherwise return 0. If the buffer is
- * actually a buffer cancel item (XFS_BLI_CANCEL is set), then decrement
+ * actually a buffer cancel item (XFS_BLF_CANCEL is set), then decrement
* the refcount on the entry in the table and remove it from the table
* if this is the last reference.
*
@@ -1721,7 +1721,7 @@ xlog_check_buffer_cancelled(
* There is nothing in the table built in pass one,
* so this buffer must not be cancelled.
*/
- ASSERT(!(flags & XFS_BLI_CANCEL));
+ ASSERT(!(flags & XFS_BLF_CANCEL));
return 0;
}
@@ -1733,7 +1733,7 @@ xlog_check_buffer_cancelled(
* There is no corresponding entry in the table built
* in pass one, so this buffer has not been cancelled.
*/
- ASSERT(!(flags & XFS_BLI_CANCEL));
+ ASSERT(!(flags & XFS_BLF_CANCEL));
return 0;
}
@@ -1752,7 +1752,7 @@ xlog_check_buffer_cancelled(
* one in the table and remove it if this is the
* last reference.
*/
- if (flags & XFS_BLI_CANCEL) {
+ if (flags & XFS_BLF_CANCEL) {
bcp->bc_refcount--;
if (bcp->bc_refcount == 0) {
if (prevp == NULL) {
@@ -1772,7 +1772,7 @@ xlog_check_buffer_cancelled(
* We didn't find a corresponding entry in the table, so
* return 0 so that the buffer is NOT cancelled.
*/
- ASSERT(!(flags & XFS_BLI_CANCEL));
+ ASSERT(!(flags & XFS_BLF_CANCEL));
return 0;
}
@@ -1874,8 +1874,8 @@ xlog_recover_do_inode_buffer(
nbits = xfs_contig_bits(data_map, map_size,
bit);
ASSERT(nbits > 0);
- reg_buf_offset = bit << XFS_BLI_SHIFT;
- reg_buf_bytes = nbits << XFS_BLI_SHIFT;
+ reg_buf_offset = bit << XFS_BLF_SHIFT;
+ reg_buf_bytes = nbits << XFS_BLF_SHIFT;
item_index++;
}
@@ -1889,7 +1889,7 @@ xlog_recover_do_inode_buffer(
}
ASSERT(item->ri_buf[item_index].i_addr != NULL);
- ASSERT((item->ri_buf[item_index].i_len % XFS_BLI_CHUNK) == 0);
+ ASSERT((item->ri_buf[item_index].i_len % XFS_BLF_CHUNK) == 0);
ASSERT((reg_buf_offset + reg_buf_bytes) <= XFS_BUF_COUNT(bp));
/*
@@ -1955,9 +1955,9 @@ xlog_recover_do_reg_buffer(
nbits = xfs_contig_bits(data_map, map_size, bit);
ASSERT(nbits > 0);
ASSERT(item->ri_buf[i].i_addr != NULL);
- ASSERT(item->ri_buf[i].i_len % XFS_BLI_CHUNK == 0);
+ ASSERT(item->ri_buf[i].i_len % XFS_BLF_CHUNK == 0);
ASSERT(XFS_BUF_COUNT(bp) >=
- ((uint)bit << XFS_BLI_SHIFT)+(nbits<<XFS_BLI_SHIFT));
+ ((uint)bit << XFS_BLF_SHIFT)+(nbits<<XFS_BLF_SHIFT));
/*
* Do a sanity check if this is a dquot buffer. Just checking
@@ -1966,7 +1966,7 @@ xlog_recover_do_reg_buffer(
*/
error = 0;
if (buf_f->blf_flags &
- (XFS_BLI_UDQUOT_BUF|XFS_BLI_PDQUOT_BUF|XFS_BLI_GDQUOT_BUF)) {
+ (XFS_BLF_UDQUOT_BUF|XFS_BLF_PDQUOT_BUF|XFS_BLF_GDQUOT_BUF)) {
if (item->ri_buf[i].i_addr == NULL) {
cmn_err(CE_ALERT,
"XFS: NULL dquot in %s.", __func__);
@@ -1987,9 +1987,9 @@ xlog_recover_do_reg_buffer(
}
memcpy(xfs_buf_offset(bp,
- (uint)bit << XFS_BLI_SHIFT), /* dest */
+ (uint)bit << XFS_BLF_SHIFT), /* dest */
item->ri_buf[i].i_addr, /* source */
- nbits<<XFS_BLI_SHIFT); /* length */
+ nbits<<XFS_BLF_SHIFT); /* length */
next:
i++;
bit += nbits;
@@ -2148,11 +2148,11 @@ xlog_recover_do_dquot_buffer(
}
type = 0;
- if (buf_f->blf_flags & XFS_BLI_UDQUOT_BUF)
+ if (buf_f->blf_flags & XFS_BLF_UDQUOT_BUF)
type |= XFS_DQ_USER;
- if (buf_f->blf_flags & XFS_BLI_PDQUOT_BUF)
+ if (buf_f->blf_flags & XFS_BLF_PDQUOT_BUF)
type |= XFS_DQ_PROJ;
- if (buf_f->blf_flags & XFS_BLI_GDQUOT_BUF)
+ if (buf_f->blf_flags & XFS_BLF_GDQUOT_BUF)
type |= XFS_DQ_GROUP;
/*
* This type of quotas was turned off, so ignore this buffer
@@ -2173,7 +2173,7 @@ xlog_recover_do_dquot_buffer(
* here which overlaps that may be stale.
*
* When meta-data buffers are freed at run time we log a buffer item
- * with the XFS_BLI_CANCEL bit set to indicate that previous copies
+ * with the XFS_BLF_CANCEL bit set to indicate that previous copies
* of the buffer in the log should not be replayed at recovery time.
* This is so that if the blocks covered by the buffer are reused for
* file data before we crash we don't end up replaying old, freed
@@ -2207,7 +2207,7 @@ xlog_recover_do_buffer_trans(
if (pass == XLOG_RECOVER_PASS1) {
/*
* In this pass we're only looking for buf items
- * with the XFS_BLI_CANCEL bit set.
+ * with the XFS_BLF_CANCEL bit set.
*/
xlog_recover_do_buffer_pass1(log, buf_f);
return 0;
@@ -2244,7 +2244,7 @@ xlog_recover_do_buffer_trans(
mp = log->l_mp;
buf_flags = XBF_LOCK;
- if (!(flags & XFS_BLI_INODE_BUF))
+ if (!(flags & XFS_BLF_INODE_BUF))
buf_flags |= XBF_MAPPED;
bp = xfs_buf_read(mp->m_ddev_targp, blkno, len, buf_flags);
@@ -2257,10 +2257,10 @@ xlog_recover_do_buffer_trans(
}
error = 0;
- if (flags & XFS_BLI_INODE_BUF) {
+ if (flags & XFS_BLF_INODE_BUF) {
error = xlog_recover_do_inode_buffer(mp, item, bp, buf_f);
} else if (flags &
- (XFS_BLI_UDQUOT_BUF|XFS_BLI_PDQUOT_BUF|XFS_BLI_GDQUOT_BUF)) {
+ (XFS_BLF_UDQUOT_BUF|XFS_BLF_PDQUOT_BUF|XFS_BLF_GDQUOT_BUF)) {
xlog_recover_do_dquot_buffer(mp, log, item, bp, buf_f);
} else {
xlog_recover_do_reg_buffer(mp, item, bp, buf_f);
diff --git a/fs/xfs/xfs_log_recover.h b/fs/xfs/xfs_log_recover.h
index 75d7492..1c55ccb 100644
--- a/fs/xfs/xfs_log_recover.h
+++ b/fs/xfs/xfs_log_recover.h
@@ -28,7 +28,7 @@
#define XLOG_RHASH(tid) \
((((__uint32_t)tid)>>XLOG_RHASH_SHIFT) & (XLOG_RHASH_SIZE-1))
-#define XLOG_MAX_REGIONS_IN_ITEM (XFS_MAX_BLOCKSIZE / XFS_BLI_CHUNK / 2 + 1)
+#define XLOG_MAX_REGIONS_IN_ITEM (XFS_MAX_BLOCKSIZE / XFS_BLF_CHUNK / 2 + 1)
/*
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 9ff48a16..1d2c7ee 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -268,6 +268,7 @@ typedef struct xfs_mount {
#define XFS_MOUNT_WSYNC (1ULL << 0) /* for nfs - all metadata ops
must be synchronous except
for space allocations */
+#define XFS_MOUNT_DELAYLOG (1ULL << 1) /* delayed logging is enabled */
#define XFS_MOUNT_DMAPI (1ULL << 2) /* dmapi is enabled */
#define XFS_MOUNT_WAS_CLEAN (1ULL << 3)
#define XFS_MOUNT_FS_SHUTDOWN (1ULL << 4) /* atomic stop of all filesystem
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index be578ec..ce558ef 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -44,6 +44,7 @@
#include "xfs_trans_priv.h"
#include "xfs_trans_space.h"
#include "xfs_inode_item.h"
+#include "xfs_trace.h"
kmem_zone_t *xfs_trans_zone;
@@ -243,9 +244,8 @@ _xfs_trans_alloc(
tp->t_type = type;
tp->t_mountp = mp;
tp->t_items_free = XFS_LIC_NUM_SLOTS;
- tp->t_busy_free = XFS_LBC_NUM_SLOTS;
xfs_lic_init(&(tp->t_items));
- XFS_LBC_INIT(&(tp->t_busy));
+ INIT_LIST_HEAD(&tp->t_busy);
return tp;
}
@@ -255,8 +255,13 @@ _xfs_trans_alloc(
*/
STATIC void
xfs_trans_free(
- xfs_trans_t *tp)
+ struct xfs_trans *tp)
{
+ struct xfs_busy_extent *busyp, *n;
+
+ list_for_each_entry_safe(busyp, n, &tp->t_busy, list)
+ xfs_alloc_busy_clear(tp->t_mountp, busyp);
+
atomic_dec(&tp->t_mountp->m_active_trans);
xfs_trans_free_dqinfo(tp);
kmem_zone_free(xfs_trans_zone, tp);
@@ -285,9 +290,8 @@ xfs_trans_dup(
ntp->t_type = tp->t_type;
ntp->t_mountp = tp->t_mountp;
ntp->t_items_free = XFS_LIC_NUM_SLOTS;
- ntp->t_busy_free = XFS_LBC_NUM_SLOTS;
xfs_lic_init(&(ntp->t_items));
- XFS_LBC_INIT(&(ntp->t_busy));
+ INIT_LIST_HEAD(&ntp->t_busy);
ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
ASSERT(tp->t_ticket != NULL);
@@ -423,7 +427,6 @@ undo_blocks:
return error;
}
-
/*
* Record the indicated change to the given field for application
* to the file system's superblock when the transaction commits.
@@ -652,7 +655,7 @@ xfs_trans_apply_sb_deltas(
* XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we
* still need to update the incore superblock with the changes.
*/
-STATIC void
+void
xfs_trans_unreserve_and_mod_sb(
xfs_trans_t *tp)
{
@@ -880,7 +883,7 @@ xfs_trans_fill_vecs(
* they could be immediately flushed and we'd have to race with the flusher
* trying to pull the item from the AIL as we add it.
*/
-static void
+void
xfs_trans_item_committed(
struct xfs_log_item *lip,
xfs_lsn_t commit_lsn,
@@ -930,26 +933,6 @@ xfs_trans_item_committed(
IOP_UNPIN(lip);
}
-/* Clear all the per-AG busy list items listed in this transaction */
-static void
-xfs_trans_clear_busy_extents(
- struct xfs_trans *tp)
-{
- xfs_log_busy_chunk_t *lbcp;
- xfs_log_busy_slot_t *lbsp;
- int i;
-
- for (lbcp = &tp->t_busy; lbcp != NULL; lbcp = lbcp->lbc_next) {
- i = 0;
- for (lbsp = lbcp->lbc_busy; i < lbcp->lbc_unused; i++, lbsp++) {
- if (XFS_LBC_ISFREE(lbcp, i))
- continue;
- xfs_alloc_clear_busy(tp, lbsp->lbc_ag, lbsp->lbc_idx);
- }
- }
- xfs_trans_free_busy(tp);
-}
-
/*
* This is typically called by the LM when a transaction has been fully
* committed to disk. It needs to unpin the items which have
@@ -984,7 +967,6 @@ xfs_trans_committed(
kmem_free(licp);
}
- xfs_trans_clear_busy_extents(tp);
xfs_trans_free(tp);
}
@@ -1012,8 +994,7 @@ xfs_trans_uncommit(
xfs_trans_unreserve_and_mod_sb(tp);
xfs_trans_unreserve_and_mod_dquots(tp);
- xfs_trans_free_items(tp, flags);
- xfs_trans_free_busy(tp);
+ xfs_trans_free_items(tp, NULLCOMMITLSN, flags);
xfs_trans_free(tp);
}
@@ -1075,6 +1056,8 @@ xfs_trans_commit_iclog(
*commit_lsn = xfs_log_done(mp, tp->t_ticket, &commit_iclog, log_flags);
tp->t_commit_lsn = *commit_lsn;
+ trace_xfs_trans_commit_lsn(tp);
+
if (nvec > XFS_TRANS_LOGVEC_COUNT)
kmem_free(log_vector);
@@ -1161,6 +1144,93 @@ xfs_trans_commit_iclog(
return xfs_log_release_iclog(mp, commit_iclog);
}
+/*
+ * Walk the log items and allocate log vector structures for
+ * each item large enough to fit all the vectors they require.
+ * Note that this format differs from the old log vector format in
+ * that there is no transaction header in these log vectors.
+ */
+STATIC struct xfs_log_vec *
+xfs_trans_alloc_log_vecs(
+ xfs_trans_t *tp)
+{
+ xfs_log_item_desc_t *lidp;
+ struct xfs_log_vec *lv = NULL;
+ struct xfs_log_vec *ret_lv = NULL;
+
+ lidp = xfs_trans_first_item(tp);
+
+ /* Bail out if we didn't find a log item. */
+ if (!lidp) {
+ ASSERT(0);
+ return NULL;
+ }
+
+ while (lidp != NULL) {
+ struct xfs_log_vec *new_lv;
+
+ /* Skip items which aren't dirty in this transaction. */
+ if (!(lidp->lid_flags & XFS_LID_DIRTY)) {
+ lidp = xfs_trans_next_item(tp, lidp);
+ continue;
+ }
+
+ /* Skip items that do not have any vectors for writing */
+ lidp->lid_size = IOP_SIZE(lidp->lid_item);
+ if (!lidp->lid_size) {
+ lidp = xfs_trans_next_item(tp, lidp);
+ continue;
+ }
+
+ new_lv = kmem_zalloc(sizeof(*new_lv) +
+ lidp->lid_size * sizeof(struct xfs_log_iovec),
+ KM_SLEEP);
+
+ /* The allocated iovec region lies beyond the log vector. */
+ new_lv->lv_iovecp = (struct xfs_log_iovec *)&new_lv[1];
+ new_lv->lv_niovecs = lidp->lid_size;
+ new_lv->lv_item = lidp->lid_item;
+ if (!ret_lv)
+ ret_lv = new_lv;
+ else
+ lv->lv_next = new_lv;
+ lv = new_lv;
+ lidp = xfs_trans_next_item(tp, lidp);
+ }
+
+ return ret_lv;
+}
+
+static int
+xfs_trans_commit_cil(
+ struct xfs_mount *mp,
+ struct xfs_trans *tp,
+ xfs_lsn_t *commit_lsn,
+ int flags)
+{
+ struct xfs_log_vec *log_vector;
+ int error;
+
+ /*
+ * Get each log item to allocate a vector structure for
+ * the log item to to pass to the log write code. The
+ * CIL commit code will format the vector and save it away.
+ */
+ log_vector = xfs_trans_alloc_log_vecs(tp);
+ if (!log_vector)
+ return ENOMEM;
+
+ error = xfs_log_commit_cil(mp, tp, log_vector, commit_lsn, flags);
+ if (error)
+ return error;
+
+ current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
+
+ /* xfs_trans_free_items() unlocks them first */
+ xfs_trans_free_items(tp, *commit_lsn, 0);
+ xfs_trans_free(tp);
+ return 0;
+}
/*
* xfs_trans_commit
@@ -1221,7 +1291,11 @@ _xfs_trans_commit(
xfs_trans_apply_sb_deltas(tp);
xfs_trans_apply_dquot_deltas(tp);
- error = xfs_trans_commit_iclog(mp, tp, &commit_lsn, flags);
+ if (mp->m_flags & XFS_MOUNT_DELAYLOG)
+ error = xfs_trans_commit_cil(mp, tp, &commit_lsn, flags);
+ else
+ error = xfs_trans_commit_iclog(mp, tp, &commit_lsn, flags);
+
if (error == ENOMEM) {
xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
error = XFS_ERROR(EIO);
@@ -1259,8 +1333,7 @@ out_unreserve:
error = XFS_ERROR(EIO);
}
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
- xfs_trans_free_items(tp, error ? XFS_TRANS_ABORT : 0);
- xfs_trans_free_busy(tp);
+ xfs_trans_free_items(tp, NULLCOMMITLSN, error ? XFS_TRANS_ABORT : 0);
xfs_trans_free(tp);
XFS_STATS_INC(xs_trans_empty);
@@ -1338,8 +1411,7 @@ xfs_trans_cancel(
/* mark this thread as no longer being in a transaction */
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
- xfs_trans_free_items(tp, flags);
- xfs_trans_free_busy(tp);
+ xfs_trans_free_items(tp, NULLCOMMITLSN, flags);
xfs_trans_free(tp);
}
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index c62beee..8c69e78 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -106,7 +106,8 @@ typedef struct xfs_trans_header {
#define XFS_TRANS_GROWFSRT_FREE 39
#define XFS_TRANS_SWAPEXT 40
#define XFS_TRANS_SB_COUNT 41
-#define XFS_TRANS_TYPE_MAX 41
+#define XFS_TRANS_CHECKPOINT 42
+#define XFS_TRANS_TYPE_MAX 42
/* new transaction types need to be reflected in xfs_logprint(8) */
#define XFS_TRANS_TYPES \
@@ -148,6 +149,7 @@ typedef struct xfs_trans_header {
{ XFS_TRANS_GROWFSRT_FREE, "GROWFSRT_FREE" }, \
{ XFS_TRANS_SWAPEXT, "SWAPEXT" }, \
{ XFS_TRANS_SB_COUNT, "SB_COUNT" }, \
+ { XFS_TRANS_CHECKPOINT, "CHECKPOINT" }, \
{ XFS_TRANS_DUMMY1, "DUMMY1" }, \
{ XFS_TRANS_DUMMY2, "DUMMY2" }, \
{ XLOG_UNMOUNT_REC_TYPE, "UNMOUNT" }
@@ -813,6 +815,7 @@ struct xfs_log_item_desc;
struct xfs_mount;
struct xfs_trans;
struct xfs_dquot_acct;
+struct xfs_busy_extent;
typedef struct xfs_log_item {
struct list_head li_ail; /* AIL pointers */
@@ -828,6 +831,11 @@ typedef struct xfs_log_item {
/* buffer item iodone */
/* callback func */
struct xfs_item_ops *li_ops; /* function list */
+
+ /* delayed logging */
+ struct list_head li_cil; /* CIL pointers */
+ struct xfs_log_vec *li_lv; /* active log vector */
+ xfs_lsn_t li_seq; /* CIL commit seq */
} xfs_log_item_t;
#define XFS_LI_IN_AIL 0x1
@@ -872,34 +880,6 @@ typedef struct xfs_item_ops {
#define XFS_ITEM_PUSHBUF 3
/*
- * This structure is used to maintain a list of block ranges that have been
- * freed in the transaction. The ranges are listed in the perag[] busy list
- * between when they're freed and the transaction is committed to disk.
- */
-
-typedef struct xfs_log_busy_slot {
- xfs_agnumber_t lbc_ag;
- ushort lbc_idx; /* index in perag.busy[] */
-} xfs_log_busy_slot_t;
-
-#define XFS_LBC_NUM_SLOTS 31
-typedef struct xfs_log_busy_chunk {
- struct xfs_log_busy_chunk *lbc_next;
- uint lbc_free; /* free slots bitmask */
- ushort lbc_unused; /* first unused */
- xfs_log_busy_slot_t lbc_busy[XFS_LBC_NUM_SLOTS];
-} xfs_log_busy_chunk_t;
-
-#define XFS_LBC_MAX_SLOT (XFS_LBC_NUM_SLOTS - 1)
-#define XFS_LBC_FREEMASK ((1U << XFS_LBC_NUM_SLOTS) - 1)
-
-#define XFS_LBC_INIT(cp) ((cp)->lbc_free = XFS_LBC_FREEMASK)
-#define XFS_LBC_CLAIM(cp, slot) ((cp)->lbc_free &= ~(1 << (slot)))
-#define XFS_LBC_SLOT(cp, slot) (&((cp)->lbc_busy[(slot)]))
-#define XFS_LBC_VACANCY(cp) (((cp)->lbc_free) & XFS_LBC_FREEMASK)
-#define XFS_LBC_ISFREE(cp, slot) ((cp)->lbc_free & (1 << (slot)))
-
-/*
* This is the type of function which can be given to xfs_trans_callback()
* to be called upon the transaction's commit to disk.
*/
@@ -950,8 +930,7 @@ typedef struct xfs_trans {
unsigned int t_items_free; /* log item descs free */
xfs_log_item_chunk_t t_items; /* first log item desc chunk */
xfs_trans_header_t t_header; /* header for in-log trans */
- unsigned int t_busy_free; /* busy descs free */
- xfs_log_busy_chunk_t t_busy; /* busy/async free blocks */
+ struct list_head t_busy; /* list of busy extents */
unsigned long t_pflags; /* saved process flags state */
} xfs_trans_t;
@@ -1025,9 +1004,6 @@ int _xfs_trans_commit(xfs_trans_t *,
void xfs_trans_cancel(xfs_trans_t *, int);
int xfs_trans_ail_init(struct xfs_mount *);
void xfs_trans_ail_destroy(struct xfs_mount *);
-xfs_log_busy_slot_t *xfs_trans_add_busy(xfs_trans_t *tp,
- xfs_agnumber_t ag,
- xfs_extlen_t idx);
extern kmem_zone_t *xfs_trans_zone;
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 9cd8090..63d81a2 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -114,7 +114,7 @@ _xfs_trans_bjoin(
xfs_buf_item_init(bp, tp->t_mountp);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
- ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_CANCEL));
+ ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL));
ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED));
if (reset_recur)
bip->bli_recur = 0;
@@ -511,7 +511,7 @@ xfs_trans_brelse(xfs_trans_t *tp,
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(bip->bli_item.li_type == XFS_LI_BUF);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
- ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_CANCEL));
+ ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL));
ASSERT(atomic_read(&bip->bli_refcount) > 0);
/*
@@ -619,7 +619,7 @@ xfs_trans_bhold(xfs_trans_t *tp,
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
- ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_CANCEL));
+ ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL));
ASSERT(atomic_read(&bip->bli_refcount) > 0);
bip->bli_flags |= XFS_BLI_HOLD;
trace_xfs_trans_bhold(bip);
@@ -641,7 +641,7 @@ xfs_trans_bhold_release(xfs_trans_t *tp,
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
- ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_CANCEL));
+ ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL));
ASSERT(atomic_read(&bip->bli_refcount) > 0);
ASSERT(bip->bli_flags & XFS_BLI_HOLD);
bip->bli_flags &= ~XFS_BLI_HOLD;
@@ -704,7 +704,7 @@ xfs_trans_log_buf(xfs_trans_t *tp,
bip->bli_flags &= ~XFS_BLI_STALE;
ASSERT(XFS_BUF_ISSTALE(bp));
XFS_BUF_UNSTALE(bp);
- bip->bli_format.blf_flags &= ~XFS_BLI_CANCEL;
+ bip->bli_format.blf_flags &= ~XFS_BLF_CANCEL;
}
lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)bip);
@@ -762,8 +762,8 @@ xfs_trans_binval(
ASSERT(!(XFS_BUF_ISDELAYWRITE(bp)));
ASSERT(XFS_BUF_ISSTALE(bp));
ASSERT(!(bip->bli_flags & (XFS_BLI_LOGGED | XFS_BLI_DIRTY)));
- ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_INODE_BUF));
- ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
+ ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_INODE_BUF));
+ ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL);
ASSERT(lidp->lid_flags & XFS_LID_DIRTY);
ASSERT(tp->t_flags & XFS_TRANS_DIRTY);
return;
@@ -774,7 +774,7 @@ xfs_trans_binval(
* in the buf log item. The STALE flag will be used in
* xfs_buf_item_unpin() to determine if it should clean up
* when the last reference to the buf item is given up.
- * We set the XFS_BLI_CANCEL flag in the buf log format structure
+ * We set the XFS_BLF_CANCEL flag in the buf log format structure
* and log the buf item. This will be used at recovery time
* to determine that copies of the buffer in the log before
* this should not be replayed.
@@ -792,9 +792,9 @@ xfs_trans_binval(
XFS_BUF_UNDELAYWRITE(bp);
XFS_BUF_STALE(bp);
bip->bli_flags |= XFS_BLI_STALE;
- bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_DIRTY);
- bip->bli_format.blf_flags &= ~XFS_BLI_INODE_BUF;
- bip->bli_format.blf_flags |= XFS_BLI_CANCEL;
+ bip->bli_flags &= ~(XFS_BLI_INODE_BUF | XFS_BLI_LOGGED | XFS_BLI_DIRTY);
+ bip->bli_format.blf_flags &= ~XFS_BLF_INODE_BUF;
+ bip->bli_format.blf_flags |= XFS_BLF_CANCEL;
memset((char *)(bip->bli_format.blf_data_map), 0,
(bip->bli_format.blf_map_size * sizeof(uint)));
lidp->lid_flags |= XFS_LID_DIRTY;
@@ -802,16 +802,16 @@ xfs_trans_binval(
}
/*
- * This call is used to indicate that the buffer contains on-disk
- * inodes which must be handled specially during recovery. They
- * require special handling because only the di_next_unlinked from
- * the inodes in the buffer should be recovered. The rest of the
- * data in the buffer is logged via the inodes themselves.
+ * This call is used to indicate that the buffer contains on-disk inodes which
+ * must be handled specially during recovery. They require special handling
+ * because only the di_next_unlinked from the inodes in the buffer should be
+ * recovered. The rest of the data in the buffer is logged via the inodes
+ * themselves.
*
- * All we do is set the XFS_BLI_INODE_BUF flag in the buffer's log
- * format structure so that we'll know what to do at recovery time.
+ * All we do is set the XFS_BLI_INODE_BUF flag in the items flags so it can be
+ * transferred to the buffer's log format structure so that we'll know what to
+ * do at recovery time.
*/
-/* ARGSUSED */
void
xfs_trans_inode_buf(
xfs_trans_t *tp,
@@ -826,7 +826,7 @@ xfs_trans_inode_buf(
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
- bip->bli_format.blf_flags |= XFS_BLI_INODE_BUF;
+ bip->bli_flags |= XFS_BLI_INODE_BUF;
}
/*
@@ -908,9 +908,9 @@ xfs_trans_dquot_buf(
ASSERT(XFS_BUF_ISBUSY(bp));
ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL);
- ASSERT(type == XFS_BLI_UDQUOT_BUF ||
- type == XFS_BLI_PDQUOT_BUF ||
- type == XFS_BLI_GDQUOT_BUF);
+ ASSERT(type == XFS_BLF_UDQUOT_BUF ||
+ type == XFS_BLF_PDQUOT_BUF ||
+ type == XFS_BLF_GDQUOT_BUF);
bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
diff --git a/fs/xfs/xfs_trans_item.c b/fs/xfs/xfs_trans_item.c
index eb3fc57..f11d37d 100644
--- a/fs/xfs/xfs_trans_item.c
+++ b/fs/xfs/xfs_trans_item.c
@@ -299,6 +299,7 @@ xfs_trans_next_item(xfs_trans_t *tp, xfs_log_item_desc_t *lidp)
void
xfs_trans_free_items(
xfs_trans_t *tp,
+ xfs_lsn_t commit_lsn,
int flags)
{
xfs_log_item_chunk_t *licp;
@@ -311,7 +312,7 @@ xfs_trans_free_items(
* Special case the embedded chunk so we don't free it below.
*/
if (!xfs_lic_are_all_free(licp)) {
- (void) xfs_trans_unlock_chunk(licp, 1, abort, NULLCOMMITLSN);
+ (void) xfs_trans_unlock_chunk(licp, 1, abort, commit_lsn);
xfs_lic_all_free(licp);
licp->lic_unused = 0;
}
@@ -322,7 +323,7 @@ xfs_trans_free_items(
*/
while (licp != NULL) {
ASSERT(!xfs_lic_are_all_free(licp));
- (void) xfs_trans_unlock_chunk(licp, 1, abort, NULLCOMMITLSN);
+ (void) xfs_trans_unlock_chunk(licp, 1, abort, commit_lsn);
next_licp = licp->lic_next;
kmem_free(licp);
licp = next_licp;
@@ -438,112 +439,3 @@ xfs_trans_unlock_chunk(
return freed;
}
-
-
-/*
- * This is called to add the given busy item to the transaction's
- * list of busy items. It must find a free busy item descriptor
- * or allocate a new one and add the item to that descriptor.
- * The function returns a pointer to busy descriptor used to point
- * to the new busy entry. The log busy entry will now point to its new
- * descriptor with its ???? field.
- */
-xfs_log_busy_slot_t *
-xfs_trans_add_busy(xfs_trans_t *tp, xfs_agnumber_t ag, xfs_extlen_t idx)
-{
- xfs_log_busy_chunk_t *lbcp;
- xfs_log_busy_slot_t *lbsp;
- int i=0;
-
- /*
- * If there are no free descriptors, allocate a new chunk
- * of them and put it at the front of the chunk list.
- */
- if (tp->t_busy_free == 0) {
- lbcp = (xfs_log_busy_chunk_t*)
- kmem_alloc(sizeof(xfs_log_busy_chunk_t), KM_SLEEP);
- ASSERT(lbcp != NULL);
- /*
- * Initialize the chunk, and then
- * claim the first slot in the newly allocated chunk.
- */
- XFS_LBC_INIT(lbcp);
- XFS_LBC_CLAIM(lbcp, 0);
- lbcp->lbc_unused = 1;
- lbsp = XFS_LBC_SLOT(lbcp, 0);
-
- /*
- * Link in the new chunk and update the free count.
- */
- lbcp->lbc_next = tp->t_busy.lbc_next;
- tp->t_busy.lbc_next = lbcp;
- tp->t_busy_free = XFS_LIC_NUM_SLOTS - 1;
-
- /*
- * Initialize the descriptor and the generic portion
- * of the log item.
- *
- * Point the new slot at this item and return it.
- * Also point the log item at its currently active
- * descriptor and set the item's mount pointer.
- */
- lbsp->lbc_ag = ag;
- lbsp->lbc_idx = idx;
- return lbsp;
- }
-
- /*
- * Find the free descriptor. It is somewhere in the chunklist
- * of descriptors.
- */
- lbcp = &tp->t_busy;
- while (lbcp != NULL) {
- if (XFS_LBC_VACANCY(lbcp)) {
- if (lbcp->lbc_unused <= XFS_LBC_MAX_SLOT) {
- i = lbcp->lbc_unused;
- break;
- } else {
- /* out-of-order vacancy */
- cmn_err(CE_DEBUG, "OOO vacancy lbcp 0x%p\n", lbcp);
- ASSERT(0);
- }
- }
- lbcp = lbcp->lbc_next;
- }
- ASSERT(lbcp != NULL);
- /*
- * If we find a free descriptor, claim it,
- * initialize it, and return it.
- */
- XFS_LBC_CLAIM(lbcp, i);
- if (lbcp->lbc_unused <= i) {
- lbcp->lbc_unused = i + 1;
- }
- lbsp = XFS_LBC_SLOT(lbcp, i);
- tp->t_busy_free--;
- lbsp->lbc_ag = ag;
- lbsp->lbc_idx = idx;
- return lbsp;
-}
-
-
-/*
- * xfs_trans_free_busy
- * Free all of the busy lists from a transaction
- */
-void
-xfs_trans_free_busy(xfs_trans_t *tp)
-{
- xfs_log_busy_chunk_t *lbcp;
- xfs_log_busy_chunk_t *lbcq;
-
- lbcp = tp->t_busy.lbc_next;
- while (lbcp != NULL) {
- lbcq = lbcp->lbc_next;
- kmem_free(lbcp);
- lbcp = lbcq;
- }
-
- XFS_LBC_INIT(&tp->t_busy);
- tp->t_busy.lbc_unused = 0;
-}
diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h
index 73e2ad3..c6e4f2c8 100644
--- a/fs/xfs/xfs_trans_priv.h
+++ b/fs/xfs/xfs_trans_priv.h
@@ -35,13 +35,14 @@ struct xfs_log_item_desc *xfs_trans_find_item(struct xfs_trans *,
struct xfs_log_item_desc *xfs_trans_first_item(struct xfs_trans *);
struct xfs_log_item_desc *xfs_trans_next_item(struct xfs_trans *,
struct xfs_log_item_desc *);
-void xfs_trans_free_items(struct xfs_trans *, int);
-void xfs_trans_unlock_items(struct xfs_trans *,
- xfs_lsn_t);
-void xfs_trans_free_busy(xfs_trans_t *tp);
-xfs_log_busy_slot_t *xfs_trans_add_busy(xfs_trans_t *tp,
- xfs_agnumber_t ag,
- xfs_extlen_t idx);
+
+void xfs_trans_unlock_items(struct xfs_trans *tp, xfs_lsn_t commit_lsn);
+void xfs_trans_free_items(struct xfs_trans *tp, xfs_lsn_t commit_lsn,
+ int flags);
+
+void xfs_trans_item_committed(struct xfs_log_item *lip,
+ xfs_lsn_t commit_lsn, int aborted);
+void xfs_trans_unreserve_and_mod_sb(struct xfs_trans *tp);
/*
* AIL traversal cursor.
diff --git a/fs/xfs/xfs_types.h b/fs/xfs/xfs_types.h
index b099045..3207752 100644
--- a/fs/xfs/xfs_types.h
+++ b/fs/xfs/xfs_types.h
@@ -75,6 +75,8 @@ typedef __uint32_t xfs_dahash_t; /* dir/attr hash value */
typedef __uint16_t xfs_prid_t; /* prid_t truncated to 16bits in XFS */
+typedef __uint32_t xlog_tid_t; /* transaction ID type */
+
/*
* These types are 64 bits on disk but are either 32 or 64 bits in memory.
* Disk based types:
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