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* fs: adfs convert to new aopsNick Piggin2007-10-161-5/+9
| | | | | | | Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* jfs: convert to new aopsNick Piggin2007-10-161-7/+10
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* minixfs: convert to new aopsNick Piggin2007-10-163-22/+53
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Andries Brouwer <Andries.Brouwer@cwi.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysv: convert to new aopsNick Piggin2007-10-163-24/+52
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* udf: convert to new aopsNick Piggin2007-10-162-26/+22
| | | | | | | | | | | | | | Convert udf to new aops. Also seem to have fixed pagecache corruption in udf_adinicb_commit_write -- page was marked uptodate when it is not. Also, fixed the silly setup where prepare_write was doing a kmap to be used in commit_write: just do kmap_atomic in write_end. Use libfs helpers to make this easier. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: <bfennema@falcon.csc.calpoly.edu> Cc: Jan Kara <jack@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ufs: convert to new aopsNick Piggin2007-10-163-23/+58
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Evgeniy Dushistov <dushistov@mail.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* jffs2: convert to new aopsNick Piggin2007-10-161-39/+66
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hostfs: convert to new aopsNick Piggin2007-10-161-41/+27
| | | | | | | | | | This also gets rid of a lot of useless read_file stuff. And also optimises the full page write case by marking a !uptodate page uptodate. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fuse: convert to new aopsNick Piggin2007-10-161-14/+32
| | | | | | | | | | | [mszeredi] - don't send zero length write requests - it is not legal for the filesystem to return with zero written bytes Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* smbfs: convert to new aopsNick Piggin2007-10-161-8/+24
| | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* nfs: convert to new aopsNick Piggin2007-10-161-20/+60
| | | | | | | | | | | [akpm@linux-foundation.org: fix against git-nfs] [peterz@infradead.org: fix against git-nfs] Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* With reiserfs no longer using the weird generic_cont_expand, remove it ↵Nick Piggin2007-10-161-20/+0
| | | | | | | | completely. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reiserfs: use generic_cont_expand_simpleVladimir Saveliev2007-10-161-2/+11
| | | | | | | | | | This patch makes reiserfs to use AOP_FLAG_CONT_EXPAND in order to get rid of the special generic_cont_expand routine Signed-off-by: Vladimir Saveliev <vs@namesys.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reiserfs: convert to new aopsVladimir Saveliev2007-10-163-19/+183
| | | | | | | | | Convert reiserfs to new aops Signed-off-by: Vladimir Saveliev <vs@namesys.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reiserfs: use generic writeVladimir Saveliev2007-10-161-1239/+1
| | | | | | | | | | Make reiserfs to write via generic routines. Original reiserfs write optimized for big writes is deadlock rone Signed-off-by: Vladimir Saveliev <vs@namesys.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* qnx4: convert to new aopsNick Piggin2007-10-161-7/+12
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Anders Larsen <al@alarsen.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bfs: convert to new aopsNick Piggin2007-10-161-4/+8
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hpfs: convert to new aopsNick Piggin2007-10-161-5/+13
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: <mikulas@artax.karlin.mff.cuni.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hfsplus: convert to new aopsNick Piggin2007-10-162-19/+20
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hfs: convert to new aopsNick Piggin2007-10-162-18/+19
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fat: convert to new aopsNick Piggin2007-10-161-11/+16
| | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: new cont helpersNick Piggin2007-10-161-100/+94
| | | | | | | | | | | | | | Rework the generic block "cont" routines to handle the new aops. Supporting cont_prepare_write would take quite a lot of code to support, so remove it instead (and we later convert all filesystems to use it). write_begin gets passed AOP_FLAG_CONT_EXPAND when called from generic_cont_expand, so filesystems can avoid the old hacks they used. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* gfs2: convert to new aopsSteven Whitehouse2007-10-161-84/+127
| | | | | | | Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xfs: convert to new aopsNick Piggin2007-10-162-30/+24
| | | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: David Chinner <dgc@sgi.com> Cc: Timothy Shimmin <tes@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ext4: convert to new aopsNick Piggin2007-10-161-54/+120
| | | | | | | | | | | Convert ext4 to use write_begin()/write_end() methods. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Dmitriy Monakhov <dmonakhov@sw.ru> Cc: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ext3: convert to new aopsNick Piggin2007-10-161-48/+115
| | | | | | | | | Various fixes and improvements Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ext2: convert to new aopsNick Piggin2007-10-163-29/+53
| | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block_dev: convert to new aopsNick Piggin2007-10-161-6/+18
| | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* implement simple fs aopsNick Piggin2007-10-165-14/+18
| | | | | | | | Implement new aops for some of the simpler filesystems. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: introduce write_begin, write_end, and perform_write aopsNick Piggin2007-10-164-129/+231
| | | | | | | | | | | | | | | These are intended to replace prepare_write and commit_write with more flexible alternatives that are also able to avoid the buffered write deadlock problems efficiently (which prepare_write is unable to do). [mark.fasheh@oracle.com: API design contributions, code review and fixes] [akpm@linux-foundation.org: various fixes] [dmonakhov@sw.ru: new aop block_write_begin fix] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: fix data-loss on errorNick Piggin2007-10-161-0/+2
| | | | | | | | | | | | | | New buffers against uptodate pages are simply be marked uptodate, while the buffer_new bit remains set. This causes error-case code to zero out parts of those buffers because it thinks they contain stale data: wrong, they are actually uptodate so this is a data loss situation. Fix this by actually clearning buffer_new and marking the buffer dirty. It makes sense to always clear buffer_new before setting a buffer uptodate. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: buffered write cleanupNick Piggin2007-10-161-8/+2
| | | | | | | | | | | | | | | | | | | | | | Quite a bit of code is used in maintaining these "cached pages" that are probably pretty unlikely to get used. It would require a narrow race where the page is inserted concurrently while this process is allocating a page in order to create the spare page. Then a multi-page write into an uncached part of the file, to make use of it. Next, the buffered write path (and others) uses its own LRU pagevec when it should be just using the per-CPU LRU pagevec (which will cut down on both data and code size cacheline footprint). Also, these private LRU pagevecs are emptied after just a very short time, in contrast with the per-CPU pagevecs that are persistent. Net result: 7.3 times fewer lru_lock acquisitions required to add the pages to pagecache for a bulk write (in 4K chunks). [this gets rid of some cond_resched() calls in readahead.c and mpage.c due to clashes in -mm. What put them there, and why? ] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: fix nobh error handlingNick Piggin2007-10-161-56/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | nobh mode error handling is not just pretty slack, it's wrong. One cannot zero out the whole page to ensure new blocks are zeroed, because it just brings the whole page "uptodate" with zeroes even if that may not be the correct uptodate data. Also, other parts of the page may already contain dirty data which would get lost by zeroing it out. Thirdly, the writeback of zeroes to the new blocks will also erase existing blocks. All these conditions are pagecache and/or filesystem corruption. The problem comes about because we didn't keep track of which buffers actually are new or old. However it is not enough just to keep only this state, because at the point we start dirtying parts of the page (new blocks, with zeroes), the handling of IO errors becomes impossible without buffers because the page may only be partially uptodate, in which case the page flags allone cannot capture the state of the parts of the page. So allocate all buffers for the page upfront, but leave them unattached so that they don't pick up any other references and can be freed when we're done. If the error path is hit, then zero the new buffers as the regular buffer path does, then attach the buffers to the page so that it can actually be written out correctly and be subject to the normal IO error handling paths. As an upshot, we save 1K of kernel stack on ia64 or powerpc 64K page systems. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: add end_buffer_read helper functionDmitry Monakhov2007-10-161-15/+17
| | | | | | | | | | Move duplicated code from end_buffer_read_XXX methods to separate helper function. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* remove ZERO_PAGENick Piggin2007-10-163-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit b5810039a54e5babf428e9a1e89fc1940fabff11 contains the note A last caveat: the ZERO_PAGE is now refcounted and managed with rmap (and thus mapcounted and count towards shared rss). These writes to the struct page could cause excessive cacheline bouncing on big systems. There are a number of ways this could be addressed if it is an issue. And indeed this cacheline bouncing has shown up on large SGI systems. There was a situation where an Altix system was essentially livelocked tearing down ZERO_PAGE pagetables when an HPC app aborted during startup. This situation can be avoided in userspace, but it does highlight the potential scalability problem with refcounting ZERO_PAGE, and corner cases where it can really hurt (we don't want the system to livelock!). There are several broad ways to fix this problem: 1. add back some special casing to avoid refcounting ZERO_PAGE 2. per-node or per-cpu ZERO_PAGES 3. remove the ZERO_PAGE completely I will argue for 3. The others should also fix the problem, but they result in more complex code than does 3, with little or no real benefit that I can see. Why? Inserting a ZERO_PAGE for anonymous read faults appears to be a false optimisation: if an application is performance critical, it would not be doing many read faults of new memory, or at least it could be expected to write to that memory soon afterwards. If cache or memory use is critical, it should not be working with a significant number of ZERO_PAGEs anyway (a more compact representation of zeroes should be used). As a sanity check -- mesuring on my desktop system, there are never many mappings to the ZERO_PAGE (eg. 2 or 3), thus memory usage here should not increase much without it. When running a make -j4 kernel compile on my dual core system, there are about 1,000 mappings to the ZERO_PAGE created per second, but about 1,000 ZERO_PAGE COW faults per second (less than 1 ZERO_PAGE mapping per second is torn down without being COWed). So removing ZERO_PAGE will save 1,000 page faults per second when running kbuild, while keeping it only saves less than 1 page clearing operation per second. 1 page clear is cheaper than a thousand faults, presumably, so there isn't an obvious loss. Neither the logical argument nor these basic tests give a guarantee of no regressions. However, this is a reasonable opportunity to try to remove the ZERO_PAGE from the pagefault path. If it is found to cause regressions, we can reintroduce it and just avoid refcounting it. The /dev/zero ZERO_PAGE usage and TLB tricks also get nuked. I don't see much use to them except on benchmarks. All other users of ZERO_PAGE are converted just to use ZERO_PAGE(0) for simplicity. We can look at replacing them all and maybe ripping out ZERO_PAGE completely when we are more satisfied with this solution. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus "snif" Torvalds <torvalds@linux-foundation.org>
* readahead: combine file_ra_state.prev_index/prev_offset into prev_posFengguang Wu2007-10-163-3/+3
| | | | | | | | | | | | | | | | | | | Combine the file_ra_state members unsigned long prev_index unsigned int prev_offset into loff_t prev_pos It is more consistent and better supports huge files. Thanks to Peter for the nice proposal! [akpm@linux-foundation.org: fix shift overflow] Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* docbook: fix filesystems contentRandy Dunlap2007-10-151-6/+35
| | | | | | | | | | | | | Fix filesystems docbook warnings. Warning(linux-2.6.23-git8//fs/debugfs/file.c:241): No description found for parameter 'name' Warning(linux-2.6.23-git8//fs/debugfs/file.c:241): No description found for parameter 'mode' Warning(linux-2.6.23-git8//fs/debugfs/file.c:241): No description found for parameter 'parent' Warning(linux-2.6.23-git8//fs/debugfs/file.c:241): No description found for parameter 'value' Warning(linux-2.6.23-git8//include/linux/jbd.h:404): No description found for parameter 'h_lockdep_map' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'locks' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2007-10-159-131/+109
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'locks' of git://linux-nfs.org/~bfields/linux: nfsd: remove IS_ISMNDLCK macro Rework /proc/locks via seq_files and seq_list helpers fs/locks.c: use list_for_each_entry() instead of list_for_each() NFS: clean up explicit check for mandatory locks AFS: clean up explicit check for mandatory locks 9PFS: clean up explicit check for mandatory locks GFS2: clean up explicit check for mandatory locks Cleanup macros for distinguishing mandatory locks Documentation: move locks.txt in filesystems/ locks: add warning about mandatory locking races Documentation: move mandatory locking documentation to filesystems/ locks: Fix potential OOPS in generic_setlease() Use list_first_entry in locks_wake_up_blocks locks: fix flock_lock_file() comment Memory shortage can result in inconsistent flocks state locks: kill redundant local variable locks: reverse order of posix_locks_conflict() arguments
| * nfsd: remove IS_ISMNDLCK macroJ. Bruce Fields2007-10-091-7/+6
| | | | | | | | | | | | | | This macro is only used in one place; in this place it seems simpler to put open-code it and move the comment to where it's used. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * Rework /proc/locks via seq_files and seq_list helpersPavel Emelyanov2007-10-092-80/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently /proc/locks is shown with a proc_read function, but its behavior is rather complex as it has to manually handle current offset and buffer length. On the other hand, files that show objects from lists can be easily reimplemented using the sequential files and the seq_list_XXX() helpers. This saves (as usually) 16 lines of code and more than 200 from the .text section. [akpm@linux-foundation.org: no externs in C] [akpm@linux-foundation.org: warning fixes] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * fs/locks.c: use list_for_each_entry() instead of list_for_each()Matthias Kaehlcke2007-10-091-10/+7
| | | | | | | | | | | | | | | | fs/locks.c: use list_for_each_entry() instead of list_for_each() in posix_locks_deadlock() and get_locks_status() Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * NFS: clean up explicit check for mandatory locksPavel Emelyanov2007-10-091-2/+1
| | | | | | | | | | | | | | | | | | | | The __mandatory_lock(inode) macro makes the same check, but makes the code more readable. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * AFS: clean up explicit check for mandatory locksPavel Emelyanov2007-10-091-2/+1
| | | | | | | | | | | | | | | | | | The __mandatory_lock(inode) macro makes the same check, but makes the code more readable. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * 9PFS: clean up explicit check for mandatory locksPavel Emelyanov2007-10-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | The __mandatory_lock(inode) macro makes the same check, but makes the code more readable. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * GFS2: clean up explicit check for mandatory locksPavel Emelyanov2007-10-091-2/+2
| | | | | | | | | | | | | | | | | | The __mandatory_lock(inode) function makes the same check, but makes the code more readable. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * Cleanup macros for distinguishing mandatory locksPavel Emelyanov2007-10-094-13/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The combination of S_ISGID bit set and S_IXGRP bit unset is used to mark the inode as "mandatory lockable" and there's a macro for this check called MANDATORY_LOCK(inode). However, fs/locks.c and some filesystems still perform the explicit i_mode checking. Besides, Andrew pointed out, that this macro is buggy itself, as it dereferences the inode arg twice. Convert this macro into static inline function and switch its users to it, making the code shorter and more readable. The __mandatory_lock() helper is to be used in places where the IS_MANDLOCK() for superblock is already known to be true. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: David Howells <dhowells@redhat.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * locks: Fix potential OOPS in generic_setlease()Pavel Emelyanov2007-10-091-9/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This code is run under lock_kernel(), which is dropped during sleeping operations, so the following race is possible: CPU1: CPU2: vfs_setlease(); vfs_setlease(); lock_kernel(); lock_kernel(); /* spin */ generic_setlease(): ... for (before = ...) /* here we found some lease after * which we will insert the new one */ fl = locks_alloc_lock(); /* go to sleep in this allocation and * drop the BKL */ generic_setlease(): ... for (before = ...) /* here we find the "before" pointing * at the one we found on CPU1 */ ->fl_change(my_before, arg); lease_modify(); locks_free_lock(); /* and we freed it */ ... unlock_kernel(); locks_insert_lock(before, fl); /* OOPS! We have just tried to add the lease * at the tail of already removed one */ The similar races are already handled in other code - all the allocations are performed before any checks/updates. Thanks to Kamalesh Babulal for testing and for a bug report on an earlier version. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
| * Use list_first_entry in locks_wake_up_blocksPavel Emelyanov2007-10-091-1/+3
| | | | | | | | | | | | | | | | This routine deletes all the elements from the list with the "while (!list_empty())" loop, and we already have a list_first_entry() macro to help it look nicer :) Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
| * locks: fix flock_lock_file() commentJ. Bruce Fields2007-10-091-2/+1
| | | | | | | | | | | | | | This comment wasn't updated when lease support was added, and it makes essentially the same mistake that the code made before a recent bugfix. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
| * Memory shortage can result in inconsistent flocks statePavel Emelyanov2007-10-091-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the flock_lock_file() is called to change the flock from F_RDLCK to F_WRLCK or vice versa the existing flock can be removed without appropriate warning. Look: for_each_lock(inode, before) { struct file_lock *fl = *before; if (IS_POSIX(fl)) break; if (IS_LEASE(fl)) continue; if (filp != fl->fl_file) continue; if (request->fl_type == fl->fl_type) goto out; found = 1; locks_delete_lock(before); <<<<<< ! break; } if after this point the subsequent locks_alloc_lock() will fail the return code will be -ENOMEM, but the existing lock is already removed. This is a known feature that such "re-locking" is not atomic, but in the racy case the file should stay locked (although by some other process), but in this case the file will be unlocked. The proposal is to prepare the lock in advance keeping no chance to fail in the future code. Found during making the flocks pid-namespaces aware. (Note: Thanks to Reuben Farrelly for finding a bug in an earlier version of this patch.) Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Reuben Farrelly <reuben-linuxkernel@reub.net>