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* Finally fix the VM bug where a file whos EOF occurs in the middle of a pagedillon2001-10-121-3/+21
| | | | | | | | | | | | | | | | | would sometimes prevent a dirty page from being cleaned, even when synced, resulting in the dirty page being re-flushed to disk every 30-60 seconds or so, forever. The problem is that when the filesystem flushes a page to its backing file it typically does not clear dirty bits representing areas of the page that are beyond the file EOF. If the file is also mmap()'d and a fault is taken, vm_fault (properly, is required to) set the vm_page_t->dirty bits to VM_PAGE_BITS_ALL. This combination could leave us with an uncleanable, unfreeable page. The solution is to have the vnode_pager detect the edge case and manually clear the dirty bits representing areas beyond the file EOF. The filesystem does the rest and the page comes up clean after the write completes. MFC after: 3 days
* Change the kernel's ucred API as follows:jhb2001-10-111-10/+8
| | | | | | | | - crhold() returns a reference to the ucred whose refcount it bumps. - crcopy() now simply copies the credentials from one credential to another and has no return value. - a new crshared() primitive is added which returns true if a ucred's refcount is > 1 and false (0) otherwise.
* KSE Milestone 2julian2001-09-121-8/+8
| | | | | | | | | | | | | | Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha
* Whitespace fixes.jhb2001-08-041-1/+1
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* whitespace / register cleanupdillon2001-07-041-2/+2
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* With Alfred's permission, remove vm_mtx in favor of a fine-grained approachdillon2001-07-041-50/+17
| | | | | | | | | (this commit is just the first stage). Also add various GIANT_ macros to formalize the removal of Giant, making it easy to test in a more piecemeal fashion. These macros will allow us to test fine-grained locks to a degree before removing Giant, and also after, and to remove Giant in a piecemeal fashion via sysctl's on those subsystems which the authors believe can operate without Giant.
* Fix a XXX comment by moving the initialization of the number of pbuf'sjhb2001-07-031-9/+9
| | | | | for the vnode pager to a new vnode pager init method instead of making it a hack in getpages().
* Don't hold the VM lock across VOP's and other things that can sleep.jhb2001-05-291-2/+19
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* - Assert Giant is held in the vnode pager methods.jhb2001-05-231-14/+18
| | | | | - Lock the VM while walking down a vm_object's backing_object list in vnode_pager_lock().
* Introduce a global lock for the vm subsystem (vm_mtx).alfred2001-05-191-15/+38
| | | | | | | | | | | | | | | | | | | vm_mtx does not recurse and is required for most low level vm operations. faults can not be taken without holding Giant. Memory subsystems can now call the base page allocators safely. Almost all atomic ops were removed as they are covered under the vm mutex. Alpha and ia64 now need to catch up to i386's trap handlers. FFS and NFS have been tested, other filesystems will need minor changes (grabbing the vm lock when twiddling page properties). Reviewed (partially) by: jake, jhb
* Revert consequences of changes to mount.h, part 2.grog2001-04-291-2/+0
| | | | Requested by: bde
* Correct #includes to work with fixed sys/mount.h.grog2001-04-231-0/+2
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* vnode_pager_freepage() is really vm_page_free() in disguise,alfred2001-04-191-14/+7
| | | | nuke vnode_pager_freepage() and replace all calls to it with vm_page_free()
* This implements a better launder limiting solution. There was a solutiondillon2000-12-261-3/+36
| | | | | | | | | | | | | | | | | | | in 4.2-REL which I ripped out in -stable and -current when implementing the low-memory handling solution. However, maxlaunder turns out to be the saving grace in certain very heavily loaded systems (e.g. newsreader box). The new algorithm limits the number of pages laundered in the first pageout daemon pass. If that is not sufficient then suceessive will be run without any limit. Write I/O is now pipelined using two sysctls, vfs.lorunningspace and vfs.hirunningspace. This prevents excessive buffered writes in the disk queues which cause long (multi-second) delays for reads. It leads to more stable (less jerky) and generally faster I/O streaming to disk by allowing required read ops (e.g. for indirect blocks and such) to occur without interrupting the write stream, amoung other things. NOTE: eventually, filesystem write I/O pipelining needs to be done on a per-device basis. At the moment it is globalized.
* Add snapshots to the fast filesystem. Most of the changes supportmckusick2000-07-111-0/+5
| | | | | | | | | | | | | | | | | | | | the gating of system calls that cause modifications to the underlying filesystem. The gating can be enabled by any filesystem that needs to consistently suspend operations by adding the vop_stdgetwritemount to their set of vnops. Once gating is enabled, the function vfs_write_suspend stops all new write operations to a filesystem, allows any filesystem modifying system calls already in progress to complete, then sync's the filesystem to disk and returns. The function vfs_write_resume allows the suspended write operations to begin again. Gating is not added by default for all filesystems as for SMP systems it adds two extra locks to such critical kernel paths as the write system call. Thus, gating should only be added as needed. Details on the use and current status of snapshots in FFS can be found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness is not included here. Unless and until you create a snapshot file, these changes should have no effect on your system (famous last words).
* Implement an optimization of the VM<->pmap API. Pass vm_page_t's directlypeter2000-05-211-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | to various pmap_*() functions instead of looking up the physical address and passing that. In many cases, the first thing the pmap code was doing was going to a lot of trouble to get back the original vm_page_t, or it's shadow pv_table entry. Inspired by: John Dyson's 1998 patches. Also: Eliminate pv_table as a seperate thing and build it into a machine dependent part of vm_page_t. This eliminates having a seperate set of structions that shadow each other in a 1:1 fashion that we often went to a lot of trouble to translate from one to the other. (see above) This happens to save 4 bytes of physical memory for each page in the system. (8 bytes on the Alpha). Eliminate the use of the phys_avail[] array to determine if a page is managed (ie: it has pv_entries etc). Store this information in a flag. Things like device_pager set it because they create vm_page_t's on the fly that do not have pv_entries. This makes it easier to "unmanage" a page of physical memory (this will be taken advantage of in subsequent commits). Add a function to add a new page to the freelist. This could be used for reclaiming the previously wasted pages left over from preloaded loader(8) files. Reviewed by: dillon
* Separate the struct bio related stuff out of <sys/buf.h> intophk2000-05-051-0/+1
| | | | | | | | | | | | | | | <sys/bio.h>. <sys/bio.h> is now a prerequisite for <sys/buf.h> but it shall not be made a nested include according to bdes teachings on the subject of nested includes. Diskdrivers and similar stuff below specfs::strategy() should no longer need to include <sys/buf.> unless they need caching of data. Still a few bogus uses of struct buf to track down. Repocopy by: peter
* Move B_ERROR flag to b_ioflags and call it BIO_ERROR.phk2000-04-021-2/+2
| | | | | | | | | | | | | (Much of this done by script) Move B_ORDERED flag to b_ioflags and call it BIO_ORDERED. Move b_pblkno and b_iodone_chain to struct bio while we transition, they will be obsoleted once bio structs chain/stack. Add bio_queue field for struct bio aware disksort. Address a lot of stylistic issues brought up by bde.
* Revert spelling mistake I made in the previous commitcharnier2000-03-271-1/+1
| | | | Requested by: Alan and Bruce
* Spellingcharnier2000-03-261-2/+2
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* Rename the existing BUF_STRATEGY() to DEV_STRATEGY()phk2000-03-201-2/+2
| | | | | | | | substitute BUF_WRITE(foo) for VOP_BWRITE(foo->b_vp, foo) substitute BUF_STRATEGY(foo) for VOP_STRATEGY(foo->b_vp, foo) This patch is machine generated except for the ccd.c and buf.h parts.
* Remove B_READ, B_WRITE and B_FREEBUF and replace them with a newphk2000-03-201-2/+2
| | | | | | | | | | | | | | | | | | | | | field in struct buf: b_iocmd. The b_iocmd is enforced to have exactly one bit set. B_WRITE was bogusly defined as zero giving rise to obvious coding mistakes. Also eliminate the redundant struct buf flag B_CALL, it can just as efficiently be done by comparing b_iodone to NULL. Should you get a panic or drop into the debugger, complaining about "b_iocmd", don't continue. It is likely to write on your disk where it should have been reading. This change is a step in the direction towards a stackable BIO capability. A lot of this patch were machine generated (Thanks to style(9) compliance!) Vinum users: Greg has not had time to test this yet, be careful.
* useracc() the prequel:phk1999-10-291-1/+0
| | | | | | | | | | | Merge the contents (less some trivial bordering the silly comments) of <vm/vm_prot.h> and <vm/vm_inherit.h> into <vm/vm.h>. This puts the #defines for the vm_inherit_t and vm_prot_t types next to their typedefs. This paves the road for the commit to follow shortly: change useracc() to use VM_PROT_{READ|WRITE} rather than B_{READ|WRITE} as argument.
* The vnode pager (used when you do file-backed mmaps) must use thedillon1999-09-171-3/+11
| | | | | | | | | | | | underlying physical sector size when aligning I/O transfer sizes. It cannot assume 512 bytes. We assume the underlying sector size is a power of 2. If it isn't, mmap() will break badly anyway (in the same way mmap broke with NFS when NFS tried to cache piecemeal write ranges in buffers, before we enforced read-buffer-before-write-piecemeal for NFS). Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
* $Id$ -> $FreeBSD$peter1999-08-281-1/+1
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* Add the (inline) function vm_page_undirty for clearing the dirty bitmaskalc1999-08-171-3/+3
| | | | | | | | of a vm_page. Use it. Submitted by: dillon
* Fix some int/long printf problems for the Alphapeter1999-07-011-3/+3
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* Convert buffer locking from using the B_BUSY and B_WANTED flags to usingmckusick1999-06-261-3/+3
| | | | | | | lockmgr locks. This commit should be functionally equivalent to the old semantics. That is, all buffer locking is done with LK_EXCLUSIVE requests. Changes to take advantage of LK_SHARED and LK_RECURSIVE will be done in future commits.
* Fix confusion of size of transfer with size of the pager.dt1999-05-151-3/+4
| | | | | PR: 11658 Broken in: 1.89 (1998/03/07)
* remove b_proc from struct buf, it's (now) unused.phk1999-05-061-5/+3
| | | | Reviewed by: dillon, bde
* The VFS/BIO subsystem contained a number of hacks in order to optimizealc1999-05-021-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | piecemeal, middle-of-file writes for NFS. These hacks have caused no end of trouble, especially when combined with mmap(). I've removed them. Instead, NFS will issue a read-before-write to fully instantiate the struct buf containing the write. NFS does, however, optimize piecemeal appends to files. For most common file operations, you will not notice the difference. The sole remaining fragment in the VFS/BIO system is b_dirtyoff/end, which NFS uses to avoid cache coherency issues with read-merge-write style operations. NFS also optimizes the write-covers-entire-buffer case by avoiding the read-before-write. There is quite a bit of room for further optimization in these areas. The VM system marks pages fully-valid (AKA vm_page_t->valid = VM_PAGE_BITS_ALL) in several places, most noteably in vm_fault. This is not correct operation. The vm_pager_get_pages() code is now responsible for marking VM pages all-valid. A number of VM helper routines have been added to aid in zeroing-out the invalid portions of a VM page prior to the page being marked all-valid. This operation is necessary to properly support mmap(). The zeroing occurs most often when dealing with file-EOF situations. Several bugs have been fixed in the NFS subsystem, including bits handling file and directory EOF situations and buf->b_flags consistancy issues relating to clearing B_ERROR & B_INVAL, and handling B_DONE. getblk() and allocbuf() have been rewritten. B_CACHE operation is now formally defined in comments and more straightforward in implementation. B_CACHE for VMIO buffers is based on the validity of the backing store. B_CACHE for non-VMIO buffers is based simply on whether the buffer is B_INVAL or not (B_CACHE set if B_INVAL clear, and vise-versa). biodone() is now responsible for setting B_CACHE when a successful read completes. B_CACHE is also set when a bdwrite() is initiated and when a bwrite() is initiated. VFS VOP_BWRITE routines (there are only two - nfs_bwrite() and bwrite()) are now expected to set B_CACHE. This means that bowrite() and bawrite() also set B_CACHE indirectly. There are a number of places in the code which were previously using buf->b_bufsize (which is DEV_BSIZE aligned) when they should have been using buf->b_bcount. These have been fixed. getblk() now clears B_DONE on return because the rest of the system is so bad about dealing with B_DONE. Major fixes to NFS/TCP have been made. A server-side bug could cause requests to be lost by the server due to nfs_realign() overwriting other rpc's in the same TCP mbuf chain. The server's kernel must be recompiled to get the benefit of the fixes. Submitted by: Matthew Dillon <dillon@apollo.backplane.com>
* Convert usage of vm_page_bits() to the new convention ("Inputs are requireddt1999-04-101-2/+2
| | | | to range within a page").
* Catch a case spotted by Tor where files mmapped could leave garbage in thejulian1999-04-051-11/+22
| | | | | | | | | | | | unallocated parts of the last page when the file ended on a frag but not a page boundary. Delimitted by tags PRE_MATT_MMAP_EOF and POST_MATT_MMAP_EOF, in files alpha/alpha/pmap.c i386/i386/pmap.c nfs/nfs_bio.c vm/pmap.h vm/vm_page.c vm/vm_page.h vm/vnode_pager.c miscfs/specfs/spec_vnops.c ufs/ufs/ufs_readwrite.c kern/vfs_bio.c Submitted by: Matt Dillon <dillon@freebsd.org> Reviewed by: Alan Cox <alc@freebsd.org>
* Correct a comment.eivind1999-03-271-2/+2
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* Reviewed by: "John S. Dyson" <dyson@iquest.net>alc1999-02-271-1/+20
| | | | | | Submitted by: Matthew Dillon <dillon@apollo.backplane.com> To prevent a deadlock, if we are extremely low on memory, force synchronous operation by the VOP_PUTPAGES in vnode_pager_putpages.
* vm_pager_put_pages() is passed an rcval array to hold per-page returndillon1999-01-241-4/+3
| | | | | | | values. The 'int' return value for the procedure was never used and not well defined in any case when there are mixed errors on pages, so it has been removed. vm_pager_put_pages() and associated vm_pager functions now return void.
* This is a rather large commit that encompasses the new swapper,dillon1999-01-211-5/+14
| | | | | | | | | | changes to the VM system to support the new swapper, VM bug fixes, several VM optimizations, and some additional revamping of the VM code. The specific bug fixes will be documented with additional forced commits. This commit is somewhat rough in regards to code cleanup issues. Reviewed by: "John S. Dyson" <root@dyson.iquest.net>, "David Greenman" <dg@root.com>
* In vnode_pager_input_old, set auio.uio_procp = curprocrvb1998-12-041-2/+2
| | | | vs auio.uio_procp = (struct proc *) 0
* Fixed two potentially serious classes of bugs:dg1998-10-131-4/+4
| | | | | | | | | | | | | | | | 1) The vnode pager wasn't properly tracking the file size due to "size" being page rounded in some cases and not in others. This sometimes resulted in corrupted files. First noticed by Terry Lambert. Fixed by changing the "size" pager_alloc parameter to be a 64bit byte value (as opposed to a 32bit page index) and changing the pagers and their callers to deal with this properly. 2) Fixed a bogus type cast in round_page() and trunc_page() that caused some 64bit offsets and sizes to be scrambled. Removing the cast required adding casts at a few dozen callers. There may be problems with other bogus casts in close-by macros. A quick check seemed to indicate that those were okay, however.
* John Dyson approved of this solution; make vnode_pager_input_old set m->validrvb1998-09-281-1/+3
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* Instantiate `nfs_mount_type' in a standard file so that it is presentbde1998-09-051-3/+2
| | | | | | | | when nfs is an LKM. Declare it in a header file. Don't forget to use it in non-Lite2 code. Initialize it to -1 instead of to 0, since 0 will soon be the mount type number for the first vfs loaded. NetBSD uses strcmp() to avoid this ugly global.
* Cosmetic changes to the PAGE_XXX macros to make them consistent withdfr1998-09-041-5/+5
| | | | the other objects in vm.
* Fix a rounding problem that causes vnode pager to fail to remove the lastluoqi1998-08-251-11/+9
| | | | | | partially filled page during a truncation. PR: kern/7422
* Change various syscalls to use size_t arguments instead of u_int.dfr1998-08-241-4/+4
| | | | | | | | | | Add some overflow checks to read/write (from bde). Change all modifications to vm_page::flags, vm_page::busy, vm_object::flags and vm_object::paging_in_progress to use operations which are not interruptable. Reviewed by: Bruce Evans <bde@zeta.org.au>
* Fixed printf format errors.bde1998-07-111-3/+9
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* Fixed printf format errors.bde1998-07-111-3/+3
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* VOP_STRATEGY grows an (struct vnode *) argumentjulian1998-07-041-3/+3
| | | | | | as the value in b_vp is often not really what you want. (and needs to be frobbed). more cleanups will follow this. Reviewed by: Bruce Evans <bde@freebsd.org>
* Some VM improvements, including elimination of alot of Sig-11dyson1998-03-161-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | problems. Tor Egge and others have helped with various VM bugs lately, but don't blame him -- blame me!!! pmap.c: 1) Create an object for kernel page table allocations. This fixes a bogus allocation method previously used for such, by grabbing pages from the kernel object, using bogus pindexes. (This was a code cleanup, and perhaps a minor system stability issue.) pmap.c: 2) Pre-set the modify and accessed bits when prudent. This will decrease bus traffic under certain circumstances. vfs_bio.c, vfs_cluster.c: 3) Rather than calculating the beginning virtual byte offset multiple times, stick the offset into the buffer header, so that the calculated offset can be reused. (Long long multiplies are often expensive, and this is a probably unmeasurable performance improvement, and code cleanup.) vfs_bio.c: 4) Handle write recursion more intelligently (but not perfectly) so that it is less likely to cause a system panic, and is also much more robust. vfs_bio.c: 5) getblk incorrectly wrote out blocks that are incorrectly sized. The problem is fixed, and writes blocks out ONLY when B_DELWRI is true. vfs_bio.c: 6) Check that already constituted buffers have fully valid pages. If not, then make sure that the B_CACHE bit is not set. (This was a major source of Sig-11 type problems.) vfs_bio.c: 7) Fix a potential system deadlock due to an incorrectly specified sleep priority while waiting for a buffer write operation. The change that I made opens the system up to serious problems, and we need to examine the issue of process sleep priorities. vfs_cluster.c, vfs_bio.c: 8) Make clustered reads work more correctly (and more completely) when buffers are already constituted, but not fully valid. (This was another system reliability issue.) vfs_subr.c, ffs_inode.c: 9) Create a vtruncbuf function, which is used by filesystems that can truncate files. The vinvalbuf forced a file sync type operation, while vtruncbuf only invalidates the buffers past the new end of file, and also invalidates the appropriate pages. (This was a system reliabiliy and performance issue.) 10) Modify FFS to use vtruncbuf. vm_object.c: 11) Make the object rundown mechanism for OBJT_VNODE type objects work more correctly. Included in that fix, create pager entries for the OBJT_DEAD pager type, so that paging requests that might slip in during race conditions are properly handled. (This was a system reliability issue.) vm_page.c: 12) Make some of the page validation routines be a little less picky about arguments passed to them. Also, support page invalidation change the object generation count so that we handle generation counts a little more robustly. vm_pageout.c: 13) Further reduce pageout daemon activity when the system doesn't need help from it. There should be no additional performance decrease even when the pageout daemon is running. (This was a significant performance issue.) vnode_pager.c: 14) Teach the vnode pager to handle race conditions during vnode deallocations.
* Complement diagnostic messages about missing per-FS VOP page operations,msmith1998-03-091-5/+14
| | | | | but don't make their absence fatal. Submitted by: terry
* This mega-commit is meant to fix numerous interrelated problems. Theredyson1998-03-071-28/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | has been some bitrot and incorrect assumptions in the vfs_bio code. These problems have manifest themselves worse on NFS type filesystems, but can still affect local filesystems under certain circumstances. Most of the problems have involved mmap consistancy, and as a side-effect broke the vfs.ioopt code. This code might have been committed seperately, but almost everything is interrelated. 1) Allow (pmap_object_init_pt) prefaulting of buffer-busy pages that are fully valid. 2) Rather than deactivating erroneously read initial (header) pages in kern_exec, we now free them. 3) Fix the rundown of non-VMIO buffers that are in an inconsistent (missing vp) state. 4) Fix the disassociation of pages from buffers in brelse. The previous code had rotted and was faulty in a couple of important circumstances. 5) Remove a gratuitious buffer wakeup in vfs_vmio_release. 6) Remove a crufty and currently unused cluster mechanism for VBLK files in vfs_bio_awrite. When the code is functional, I'll add back a cleaner version. 7) The page busy count wakeups assocated with the buffer cache usage were incorrectly cleaned up in a previous commit by me. Revert to the original, correct version, but with a cleaner implementation. 8) The cluster read code now tries to keep data associated with buffers more aggressively (without breaking the heuristics) when it is presumed that the read data (buffers) will be soon needed. 9) Change to filesystem lockmgr locks so that they use LK_NOPAUSE. The delay loop waiting is not useful for filesystem locks, due to the length of the time intervals. 10) Correct and clean-up spec_getpages. 11) Implement a fully functional nfs_getpages, nfs_putpages. 12) Fix nfs_write so that modifications are coherent with the NFS data on the server disk (at least as well as NFS seems to allow.) 13) Properly support MS_INVALIDATE on NFS. 14) Properly pass down MS_INVALIDATE to lower levels of the VM code from vm_map_clean. 15) Better support the notion of pages being busy but valid, so that fewer in-transit waits occur. (use p->busy more for pageouts instead of PG_BUSY.) Since the page is fully valid, it is still usable for reads. 16) It is possible (in error) for cached pages to be busy. Make the page allocation code handle that case correctly. (It should probably be a printf or panic, but I want the system to handle coding errors robustly. I'll probably add a printf.) 17) Correct the design and usage of vm_page_sleep. It didn't handle consistancy problems very well, so make the design a little less lofty. After vm_page_sleep, if it ever blocked, it is still important to relookup the page (if the object generation count changed), and verify it's status (always.) 18) In vm_pageout.c, vm_pageout_clean had rotted, so clean that up. 19) Push the page busy for writes and VM_PROT_READ into vm_pageout_flush. 20) Fix vm_pager_put_pages and it's descendents to support an int flag instead of a boolean, so that we can pass down the invalidate bit.
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