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* ext4: fix 64-bit number truncation warningChen Gang2014-04-071-1/+1
| | | | | | | | | | | | | | '0x7FDEADBEEF' will be truncated to 32-bit number under unicore32. Need append 'ULL' for it. The related warning (with allmodconfig under unicore32): CC [M] fs/ext4/extents_status.o fs/ext4/extents_status.c: In function "__es_remove_extent": fs/ext4/extents_status.c:813: warning: integer constant is too large for "long" type Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: silence warnings in extent status tree debugging codeEric Whitney2014-02-201-7/+7
| | | | | | | | | Adjust the conversion specifications in a few optionally compiled debug messages to match the return type of ext4_es_status(). Also, make a couple of minor grammatical message edits while we're at it. Signed-off-by: Eric Whitney <enwlinux@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: add ext4_es_store_pblock_status()Theodore Ts'o2014-02-191-8/+6
| | | | | | | | | | | | | | Avoid false positives by static code analysis tools such as sparse and coverity caused by the fact that we set the physical block, and then the status in the extent_status structure. It is also more efficient to set both of these values at once. Addresses-Coverity-Id: #989077 Addresses-Coverity-Id: #989078 Addresses-Coverity-Id: #1080722 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
* fs: convert fs shrinkers to new scan/count APIDave Chinner2013-09-101-9/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the filesystem shrinkers to use the new API, and standardise some of the behaviours of the shrinkers at the same time. For example, nr_to_scan means the number of objects to scan, not the number of objects to free. I refactored the CIFS idmap shrinker a little - it really needs to be broken up into a shrinker per tree and keep an item count with the tree root so that we don't need to walk the tree every time the shrinker needs to count the number of objects in the tree (i.e. all the time under memory pressure). [glommer@openvz.org: fixes for ext4, ubifs, nfs, cifs and glock. Fixes are needed mainly due to new code merged in the tree] [assorted fixes folded in] Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Glauber Costa <glommer@openvz.org> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Rientjes <rientjes@google.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: J. Bruce Fields <bfields@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ext4: isolate ext4_extents.h fileZheng Liu2013-08-281-18/+2
| | | | | | | | | | | | | | | | | | | After applied the commit (4a092d73), we have reduced the number of source files that need to #include ext4_extents.h. But we can do better. This commit defines ext4_zeroout_es() in extents.c and move EXT_MAX_BLOCKS into ext4.h in order not to include ext4_extents.h in indirect.c and ioctl.c. Meanwhile we just need to include this file in extent_status.c when ES_AGGRESSIVE_TEST is defined. Otherwise, this commit removes a duplicated declaration in trace/events/ext4.h. After applied this patch, we just need to include ext4_extents.h file in {super,migrate,move_extents,extents}.c, and it is easy for us to define a new extent disk layout. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: add support for extent pre-cachingTheodore Ts'o2013-08-161-21/+51
| | | | | | | | | | | | | | | Add a new fiemap flag which forces the all of the extents in an inode to be cached in the extent_status tree. This is critically important when using AIO to a preallocated file, since if we need to read in blocks from the extent tree, the io_submit(2) system call becomes synchronous, and the AIO is no longer "A", which is bad. In addition, for most files which have an external leaf tree block, the cost of caching the information in the extent status tree will be less than caching the entire 4k block in the buffer cache. So it is generally a win to keep the extent information cached. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: cache all of an extent tree's leaf block upon readingTheodore Ts'o2013-08-161-1/+36
| | | | | | | | | | | When we read in an extent tree leaf block from disk, arrange to have all of its entries cached. In nearly all cases the in-memory representation will be more compact than the on-disk representation in the buffer cache, and it allows us to get the information without having to traverse the extent tree for successive extents. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
* ext4: use unsigned int for es_status valuesTheodore Ts'o2013-08-161-3/+3
| | | | | | | | | | | Don't use an unsigned long long for the es_status flags; this requires that we pass 64-bit values around which is painful on 32-bit systems. Instead pass the extent status flags around using the low 4 bits of an unsigned int, and shift them into place when we are reading or writing es_pblk. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
* ext4: make the extent_status code more robust against ENOMEM failuresTheodore Ts'o2013-07-151-12/+39
| | | | | | | | | | | | | | | | | Some callers of ext4_es_remove_extent() and ext4_es_insert_extent() may not be completely robust against ENOMEM failures (or the consequences of reflecting ENOMEM back up to userspace may lead to xfstest or user application failure). To mitigate against this, when trying to insert an entry in the extent status tree, try to shrink the inode's extent status tree before returning ENOMEM. If there are entries which don't record information about extents under delayed allocations, freeing one of them is preferable to returning ENOMEM. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
* ext4: fix spelling errors and a comment in extent_status treeTheodore Ts'o2013-07-131-12/+10
| | | | | | | | | | | Replace "assertation" with "assertion" in lots and lots of debugging messages. Correct the comment stating when ext4_es_insert_extent() is used. It was no doubt tree at one point, but it is no longer true... Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Zheng Liu <gnehzuil.liu@gmail.com>
* ext4: improve extent cache shrink mechanism to avoid to burn CPU timeZheng Liu2013-07-011-20/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now we maintain an proper in-order LRU list in ext4 to reclaim entries from extent status tree when we are under heavy memory pressure. For keeping this order, a spin lock is used to protect this list. But this lock burns a lot of CPU time. We can use the following steps to trigger it. % cd /dev/shm % dd if=/dev/zero of=ext4-img bs=1M count=2k % mkfs.ext4 ext4-img % mount -t ext4 -o loop ext4-img /mnt % cd /mnt % for ((i=0;i<160;i++)); do truncate -s 64g $i; done % for ((i=0;i<160;i++)); do cp $i /dev/null &; done % perf record -a -g % perf report This commit tries to fix this problem. Now a new member called i_touch_when is added into ext4_inode_info to record the last access time for an inode. Meanwhile we never need to keep a proper in-order LRU list. So this can avoid to burns some CPU time. When we try to reclaim some entries from extent status tree, we use list_sort() to get a proper in-order list. Then we traverse this list to discard some entries. In ext4_sb_info, we use s_es_last_sorted to record the last time of sorting this list. When we traverse the list, we skip the inode that is newer than this time, and move this inode to the tail of LRU list. When the head of the list is newer than s_es_last_sorted, we will sort the LRU list again. In this commit, we break the loop if s_extent_cache_cnt == 0 because that means that all extents in extent status tree have been reclaimed. Meanwhile in this commit, ext4_es_{un}register_shrinker()'s prototype is changed to save a local variable in these functions. Reported-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: fix fio regressionYan, Zheng2013-05-031-5/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We (Linux Kernel Performance project) found a regression introduced by commit: f7fec032aa ext4: track all extent status in extent status tree The commit causes about 20% performance decrease in fio random write test. Profiler shows that rb_next() uses a lot of CPU time. The call stack is: rb_next ext4_es_find_delayed_extent ext4_map_blocks _ext4_get_block ext4_get_block_write __blockdev_direct_IO ext4_direct_IO generic_file_direct_write __generic_file_aio_write ext4_file_write aio_rw_vect_retry aio_run_iocb do_io_submit sys_io_submit system_call_fastpath io_submit td_io_getevents io_u_queued_complete thread_main main __libc_start_main The cause is that ext4_es_find_delayed_extent() doesn't have an upper bound, it keeps searching until a delayed extent is found. When there are a lots of non-delayed entries in the extent state tree, ext4_es_find_delayed_extent() may uses a lot of CPU time. Reported-by: LKP project <lkp@linux.intel.com> Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Cc: "Theodore Ts'o" <tytso@mit.edu>
* ext4: update extent status tree after an extent is zeroed outZheng Liu2013-03-101-0/+17
| | | | | | | | | | | | | | | When we try to split an extent, this extent could be zeroed out and mark as initialized. But we don't know this in ext4_map_blocks because it only returns a length of allocated extent. Meanwhile we will mark this extent as uninitialized because we only check m_flags. This commit update extent status tree when we try to split an unwritten extent. We don't need to worry about the status of this extent because we always mark it as initialized. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Dmitry Monakhov <dmonakhov@openvz.org>
* ext4: add self-testing infrastructure to do a sanity checkDmitry Monakhov2013-03-101-0/+175
| | | | | | | | | | | | | | | | | | | | | | | | This commit adds a self-testing infrastructure like extent tree does to do a sanity check for extent status tree. After status tree is as a extent cache, we'd better to make sure that it caches right result. After applied this commit, we will get a lot of messages when we run xfstests as below. ... kernel: ES len assertation failed for inode: 230 retval 1 != map->m_len 3 in ext4_map_blocks (allocation) ... kernel: ES cache assertation failed for inode: 230 es_cached ex [974/2/4781/20] != found ex [974/1/4781/1000] ... kernel: ES insert assertation failed for inode: 635 ex_status [0/45/21388/w] != es_status [44/1/21432/u] ... Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: avoid a potential overflow in ext4_es_can_be_merged()Zheng Liu2013-03-101-5/+15
| | | | | | | | | Check the length of an extent to avoid a potential overflow in ext4_es_can_be_merged(). Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Dmitry Monakhov <dmonakhov@openvz.org>
* ext4: use percpu counter for extent cache countTheodore Ts'o2013-03-021-4/+4
| | | | | | | | | | | Use a percpu counter rather than atomic types for shrinker accounting. There's no need for ultimate accuracy in the shrinker, so this should come a little more cheaply. The percpu struct is somewhat large, but there was a big gap before the cache-aligned s_es_lru_lock anyway, and it fits nicely in there. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: optimize ext4_es_shrink()Theodore Ts'o2013-02-281-26/+13
| | | | | | | | | | | | | | | When the system is under memory pressure, ext4_es_srhink() will get called very often. So optimize returning the number of items in the file system's extent status cache by keeping a per-filesystem count, instead of calculating it each time by scanning all of the inodes in the extent status cache. Also rename the slab used for the extent status cache to be "ext4_extent_status" so it's obviousl the slab in question is created by ext4. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Zheng Liu <gnehzuil.liu@gmail.com>
* ext4: no need to remove extent if len is 0 in ext4_es_remove_extent()Eryu Guan2013-02-221-0/+6
| | | | | | | | | | | | | | | | | | | | | | len is 0 means no extent needs to be removed, so return immediately. Otherwise it could trigger the following BUG_ON() in ext4_es_remove_extent() end = lblk + len - 1; BUG_ON(end < lblk); This could be reproduced by a simple truncate(1) command by an unprivileged user truncate -s $(($((2**32 - 1)) * 4096)) /mnt/ext4/testfile The same is true for __es_insert_extent(). Patched kernel passed xfstests regression test. Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
* ext4: reclaim extents from extent status treeZheng Liu2013-02-181-0/+156
| | | | | | | | | | | | | | | | | | | | | | | | | | | Although extent status is loaded on-demand, we also need to reclaim extent from the tree when we are under a heavy memory pressure because in some cases fragmented extent tree causes status tree costs too much memory. Here we maintain a lru list in super_block. When the extent status of an inode is accessed and changed, this inode will be move to the tail of the list. The inode will be dropped from this list when it is cleared. In the inode, a counter is added to count the number of cached objects in extent status tree. Here only written/unwritten/hole extent is counted because delayed extent doesn't be reclaimed due to fiemap, bigalloc and seek_data/hole need it. The counter will be increased as a new extent is allocated, and it will be decreased as a extent is freed. In this commit we use normal shrinker framework to reclaim memory from the status tree. ext4_es_reclaim_extents_count() traverses the lru list to count the number of reclaimable extents. ext4_es_shrink() tries to reclaim written/unwritten/hole extents from extent status tree. The inode that has been shrunk is moved to the tail of lru list. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jan kara <jack@suse.cz>
* ext4: adjust some functions for reclaiming extents from extent status treeZheng Liu2013-02-181-26/+24
| | | | | | | | | This commit changes some interfaces in extent status tree because we need to use inode to count the cached objects in a extent status tree. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jan kara <jack@suse.cz>
* ext4: lookup block mapping in extent status treeZheng Liu2013-02-181-0/+60
| | | | | | | | | | | | | | | | | | | After tracking all extent status, we already have a extent cache in memory. Every time we want to lookup a block mapping, we can first try to lookup it in extent status tree to avoid a potential disk I/O. A new function called ext4_es_lookup_extent is defined to finish this work. When we try to lookup a block mapping, we always call ext4_map_blocks and/or ext4_da_map_blocks. So in these functions we first try to lookup a block mapping in extent status tree. A new flag EXT4_GET_BLOCKS_NO_PUT_HOLE is used in ext4_da_map_blocks in order not to put a hole into extent status tree because this hole will be converted to delayed extent in the tree immediately. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jan kara <jack@suse.cz>
* ext4: rename and improbe ext4_es_find_extent()Zheng Liu2013-02-181-20/+20
| | | | | | | | | | | This commit renames ext4_es_find_extent with ext4_es_find_delayed_extent and improve this function. First, we split input and output parameter. Second, this function never return the first block of the next delayed extent after 'es'. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jan kara <jack@suse.cz>
* ext4: add physical block and status member into extent status treeZheng Liu2013-02-181-12/+55
| | | | | | | | | | | | | | | This commit adds two members in extent_status structure to let it record physical block and extent status. Here es_pblk is used to record both of them because physical block only has 48 bits. So extent status could be stashed into it so that we can save some memory. Now written, unwritten, delayed and hole are defined as status. Due to new member is added into extent status tree, all interfaces need to be adjusted. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
* ext4: refine extent status treeZheng Liu2013-02-181-141/+181
| | | | | | | | | | | | | | | | | | | | | | This commit refines the extent status tree code. 1) A prefix 'es_' is added to to the extent status tree structure members. 2) Refactored es_remove_extent() so that __es_remove_extent() can be used by es_insert_extent() to remove the old extent entry(-ies) before inserting a new one. 3) Rename extent_status_end() to ext4_es_end() 4) ext4_es_can_be_merged() is define to check whether two extents can be merged or not. 5) Update and clarified comments. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
* ext4: add some tracepoints in extent status treeZheng Liu2012-11-081-0/+8
| | | | | | | This patch adds some tracepoints in extent status tree. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: add operations on extent status treeZheng Liu2012-11-081-0/+492
This patch adds operations on a extent status tree. CC: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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