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2011-03-14GFS2: Update to AIL list lockingSteven Whitehouse
The previous patch missed a couple of places where the AIL list needed locking, so this fixes up those places, plus a comment is corrected too. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Chinner <dchinner@redhat.com>
2011-03-11GFS2: introduce AIL lockDave Chinner
The log lock is currently used to protect the AIL lists and the movements of buffers into and out of them. The lists are self contained and no log specific items outside the lists are accessed when starting or emptying the AIL lists. Hence the operation of the AIL does not require the protection of the log lock so split them out into a new AIL specific lock to reduce the amount of traffic on the log lock. This will also reduce the amount of serialisation that occurs when the gfs2_logd pushes on the AIL to move it forward. This reduces the impact of log pushing on sequential write throughput. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-11GFS2: fix block allocation check for fallocateBenjamin Marzinski
GFS2 fallocate wasn't properly checking if a blocks were already allocated. In write_empty_blocks(), if a page didn't have buffer_heads attached, GFS2 was always treating it as if there were no blocks allocated for that page. GFS2 now calls gfs2_block_map() to check if the blocks are allocated before writing them out. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-11GFS2: Optimize glock multiple-dequeue codeBob Peterson
This is a small patch that optimizes multiple glock dequeue operations. It changes the unlock order to be more efficient and makes it easier for lock debugging tools to unravel. It also eliminates the need for the temp variable x, although that would likely be optimized out. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-09GFS2: Remove potential race in flock codeSteven Whitehouse
This patch ensures that we always wait for glock demotion when dropping flocks on a file in order to prevent any race conditions associated with further flock calls or closing the file. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-09GFS2: Fix glock deallocation raceSteven Whitehouse
This patch fixes a race in deallocating glocks which was introduced in the RCU glock patch. We need to ensure that the glock count is kept correct even in the case that there is a race to add a new glock into the hash table. Also, to avoid having to wait for an RCU grace period, the glock counter can be decremented before call_rcu() is called. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-03-09GFS2: quota allows exceeding hard limitAbhijith Das
Immediately after being synced to disk, cached quotas are zeroed out and a subsequent access of the cached quotas results in incorrect zero values. This meant that gfs2 assumed the actual usage to be the zero (or near-zero) usage values it found in the cached quotas and comparison against warn/limits never triggered a quota violation. This patch adds a new flag QDF_REFRESH that is set after a sync so that the cached quotas are forcefully refreshed from disk on a subsequent access on seeing this flag set. Resolves: rhbz#675944 Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-02-24GFS2: deallocation performance patchBob Peterson
This patch is a performance improvement to GFS2's dealloc code. Rather than update the quota file and statfs file for every single block that's stripped off in unlink function do_strip, this patch keeps track and updates them once for every layer that's stripped. This is done entirely inside the existing transaction, so there should be no risk of corruption. The other functions that deallocate blocks will be unaffected because they are using wrapper functions that do the same thing that they do today. I tested this code on my roth cluster by creating 200 files in a directory, each of which is 100MB, then on four nodes, I simultaneously deleted the files, thus competing for GFS2 resources (but different files). The commands I used were: [root@roth-01]# time for i in `seq 1 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done [root@roth-02]# time for i in `seq 2 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done [root@roth-03]# time for i in `seq 3 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done [root@roth-05]# time for i in `seq 4 4 200` ; do rm /mnt/gfs2/bigdir/gfs2.$i; done The performance increase was significant: roth-01 roth-02 roth-03 roth-05 --------- --------- --------- --------- old: real 0m34.027 0m25.021s 0m23.906s 0m35.646s new: real 0m22.379s 0m24.362s 0m24.133s 0m18.562s Total time spent deleting: old: 118.6s new: 89.4 For this particular case, this showed a 25% performance increase for GFS2 unlinks. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-02-07GFS2: panics on quotacheck updateAbhijith Das
Handle block allocation for forceful unstuffing of quota dinode during quota update using quotactl(). Also fix block reservation for special cases when quotas cross over block boundaries and update 2 blocks instead of 1. Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-02-02GFS2: Improve cluster mmap scalabilitySteven Whitehouse
The mmap system call grabs a glock when an update to atime maybe required. It does this in order to ensure that the flags on the inode are uptodate, but since it will only mark atime for a future update, an exclusive lock is not required here (one will be taken later when the actual update is performed). Also, the lock can be skipped when the mount is marked noatime in addition to the original check which only looked at the noatime flag for the inode itself. This should increase the scalability of the mmap call when multiple nodes are all mmaping the same file. Reported-by: Scooter Morris <scooter@cgl.ucsf.edu> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-01-31GFS2: Fix glock queue trace pointSteven Whitehouse
Somehow this tracepoint landed up in the wrong place. This moves it to where it should be. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-01-21GFS2: Post-VFS scale update for RCU path walkSteven Whitehouse
We can allow a few more cases to use RCU path walking than originally allowed. It should be possible to also enable RCU path walking when the glock is already cached. Thats a bit more complicated though, so left for a future patch. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Nick Piggin <npiggin@gmail.com>
2011-01-21GFS2: Use RCU for glock hash tableSteven Whitehouse
This has a number of advantages: - Reduces contention on the hash table lock - Makes the code smaller and simpler - Should speed up glock dumps when under load - Removes ref count changing in examine_bucket - No longer need hash chain lock in glock_put() in common case There are some further changes which this enables and which we may do in the future. One is to look at using SLAB_RCU, and another is to look at using a per-cpu counter for the per-sb glock counter, since that is touched twice in the lifetime of each glock (but only used at umount time). Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-01-18GFS2: Fix error path in gfs2_lookup_by_inum()Steven Whitehouse
In the (impossible, except if there is fs corruption) error path in gfs2_lookup_by_inum() if the call to gfs2_inode_refresh() fails, it was leaving the function by calling iput() rather than iget_failed(). This would cause future lookups of the same inode to block forever. This patch fixes the problem by moving the call to gfs2_inode_refresh() into gfs2_inode_lookup() where iget_failed() is part of the error path already. Also this cleans up some unreachable code and makes gfs2_set_iop() static. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-01-18GFS2: remove iopen glocks from cache on failed deletesBenjamin Marzinski
When a file gets deleted on GFS2, if a node can't get an exclusive lock on the file's iopen glock, it punts on actually freeing up the space, because another node is using the file. When it does this, it needs to drop the iopen glock from its cache so that the other node can get an exclusive lock on it. Now, gfs2_delete_inode() sets GL_NOCACHE before dropping the shared lock on the iopen glock in preparation for grabbing it in the exclusive state. Since the node needs the glock in the exclusive state, dropping the shared lock from the cache doesn't slow down the case where no other nodes are using the file. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-01-17fallocate should be a file operationChristoph Hellwig
Currently all filesystems except XFS implement fallocate asynchronously, while XFS forced a commit. Both of these are suboptimal - in case of O_SYNC I/O we really want our allocation on disk, especially for the !KEEP_SIZE case where we actually grow the file with user-visible zeroes. On the other hand always commiting the transaction is a bad idea for fast-path uses of fallocate like for example in recent Samba versions. Given that block allocation is a data plane operation anyway change it from an inode operation to a file operation so that we have the file structure available that lets us check for O_SYNC. This also includes moving the code around for a few of the filesystems, and remove the already unnedded S_ISDIR checks given that we only wire up fallocate for regular files. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-17make the feature checks in ->fallocate future proofChristoph Hellwig
Instead of various home grown checks that might need updates for new flags just check for any bit outside the mask of the features supported by the filesystem. This makes the check future proof for any newly added flag. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-13Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits) block: ensure that completion error gets properly traced blktrace: add missing probe argument to block_bio_complete block cfq: don't use atomic_t for cfq_group block cfq: don't use atomic_t for cfq_queue block: trace event block fix unassigned field block: add internal hd part table references block: fix accounting bug on cross partition merges kref: add kref_test_and_get bio-integrity: mark kintegrityd_wq highpri and CPU intensive block: make kblockd_workqueue smarter Revert "sd: implement sd_check_events()" block: Clean up exit_io_context() source code. Fix compile warnings due to missing removal of a 'ret' variable fs/block: type signature of major_to_index(int) to major_to_index(unsigned) block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p) cfq-iosched: don't check cfqg in choose_service_tree() fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors cdrom: export cdrom_check_events() sd: implement sd_check_events() sr: implement sr_check_events() ...
2011-01-12Gfs2: fail if we try to use hole punchJosef Bacik
Gfs2 doesn't have the ability to punch holes yet, so make sure we return EOPNOTSUPP if we try to use hole punching through fallocate. This support can be added later. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12switch gfs2, close racesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-10headers: kobject.h reduxAlexey Dobriyan
Remove kobject.h from files which don't need it, notably, sched.h and fs.h. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-07Merge branch 'vfs-scale-working' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin * 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits) fs: scale mntget/mntput fs: rename vfsmount counter helpers fs: implement faster dentry memcmp fs: prefetch inode data in dcache lookup fs: improve scalability of pseudo filesystems fs: dcache per-inode inode alias locking fs: dcache per-bucket dcache hash locking bit_spinlock: add required includes kernel: add bl_list xfs: provide simple rcu-walk ACL implementation btrfs: provide simple rcu-walk ACL implementation ext2,3,4: provide simple rcu-walk ACL implementation fs: provide simple rcu-walk generic_check_acl implementation fs: provide rcu-walk aware permission i_ops fs: rcu-walk aware d_revalidate method fs: cache optimise dentry and inode for rcu-walk fs: dcache reduce branches in lookup path fs: dcache remove d_mounted fs: fs_struct use seqlock fs: rcu-walk for path lookup ...
2011-01-07fs: provide rcu-walk aware permission i_opsNick Piggin
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: rcu-walk aware d_revalidate methodNick Piggin
Require filesystems be aware of .d_revalidate being called in rcu-walk mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning -ECHILD from all implementations. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce branches in lookup pathNick Piggin
Reduce some branches and memory accesses in dcache lookup by adding dentry flags to indicate common d_ops are set, rather than having to check them. This saves a pointer memory access (dentry->d_op) in common path lookup situations, and saves another pointer load and branch in cases where we have d_op but not the particular operation. Patched with: git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: icache RCU free inodesNick Piggin
RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: change d_hash for rcu-walkNick Piggin
Change d_hash so it may be called from lock-free RCU lookups. See similar patch for d_compare for details. For in-tree filesystems, this is just a mechanical change. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: change d_delete semanticsNick Piggin
Change d_delete from a dentry deletion notification to a dentry caching advise, more like ->drop_inode. Require it to be constant and idempotent, and not take d_lock. This is how all existing filesystems use the callback anyway. This makes fine grained dentry locking of dput and dentry lru scanning much simpler. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2010-12-16GFS2: Don't flush delete workqueue when releasing the transaction lockSteven Whitehouse
There is no requirement to flush the delete workqueue before a gfs2 filesystem is suspended. The workqueue's work will just be suspended along with the rest of the tasks on the filesystem. The resolves a deadlock situation where the transaction lock's demotion code was trying to flush the delete workqueue while at the same time, the workqueue was waiting for the transaction lock. The delete workqueue is flushed by gfs2_make_fs_ro() already, so that umount/remount are correctly protected anyway. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-12-07GFS2: fsck.gfs2 reported statfs error after gfs2_growBob Peterson
When you do gfs2_grow it failed to take the very last rgrp into account when adding up the new free space due to an off-by-one error. It was not reading the last rgrp from the rindex because of a check for "<=" that should have been "<". Therefore, fsck.gfs2 was finding (and fixing) an error with the system statfs file. Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2010-11-30GFS2: Merge glock state fields into a bitfieldSteven Whitehouse
We can only merge the fields into a bitfield if the locking rules for them are the same. In this case gl_spin covers all of the fields (write side) but a couple of them are used with GLF_LOCK as the read side lock, which should be ok since we know that the field in question won't be changing at the time. The gl_req setting has to be done earlier (in glock.c) in order to place it under gl_spin. The gl_reply setting also has to be brought under gl_spin in order to comply with the new rules. This saves 4*sizeof(unsigned int) per glock. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Bob Peterson <rpeterso@redhat.com>
2010-11-30GFS2: Fix uninitialised error value in previous patchSteven Whitehouse
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: fix recursive locking during rindex truncatesBenjamin Marzinski
When you truncate the rindex file, you need to avoid calling gfs2_rindex_hold, since you already hold it. However, if you haven't already read in the resource groups, you need to do that. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: reread rindex when necessary to grow rindexBenjamin Marzinski
When GFS2 grew the filesystem, it was never rereading the rindex file during the grow. This is necessary for large grows when the filesystem is almost full, and GFS2 needs to use some of the space allocated earlier in the grow to complete it. Now, if GFS2 fails to reserve the necessary space and the rindex file is not uptodate, it rereads it. Also, the only difference between gfs2_ri_update() and gfs2_ri_update_special() was that gfs2_ri_update_special() didn't clear out the existing resource groups, since you knew that it was only called when there were no resource groups. Attempting to clear out the resource groups when there are none takes almost no time, and rarely happens, so I simply removed gfs2_ri_update_special(). Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Remove duplicate #defines from glock.hSteven Whitehouse
There are a number of duplicated #defines in glock.h plus one which is unused. This removes the extra definitions. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Clean up of gdlm_lock functionSteven Whitehouse
The DLM never returns -EAGAIN in response to dlm_lock(), and even if it did, the test in gdlm_lock() was wrong anyway. Once that test is removed, it is possible to greatly simplify this code by simply using a "normal" error return code (0 for success). We then no longer need the LM_OUT_ASYNC return code which can be removed. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Allow gfs2 to update quota usage values through the quotactl interfaceAbhijith Das
With this patch the gfs2_set_dqblk() function will be able to update the quota usage block count (FS_DQ_BCOUNT) in addition to the already supported FS_DQ_BHARD (limit) and FS_DQ_BSOFT (warn) fields of the dquot structure. Signed-off-by: Abhi Das <adas@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: fs/gfs2/glock.h: Add __attribute__((format(printf,2,3)) to gfs2_print_dbgJoe Perches
Functions that use printf formatting, especially those that use %pV, should have their uses of printf format and arguments checked by the compiler. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: fs/gfs2/glock.c: Use printf extension %pVJoe Perches
Using %pV reduces the number of printk calls and eliminates any possible message interleaving from other printk calls. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Clean up duplicated setattr codeSteven Whitehouse
While preparing the last patch I noticed that the gfs2_setattr_simple code had been duplicated into two other places. This patch updates those to call gfs2_setattr_simple rather than open coding it. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Remove unreachable calls to vmtruncateSteven Whitehouse
Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: fs/gfs2/glock.c: Convert sprintf_symbol to %pSJoe Perches
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-30GFS2: Change two WQ_RESCUERs into WQ_MEM_RECLAIMSteven Whitehouse
The WQ_RESCUER flag should only be used internally to the workqueue implementation. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Tejun Heo <tj@kernel.org>
2010-11-27Merge branch 'cleanup-bd_claim' of ↵Jens Axboe
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into for-2.6.38/core
2010-11-19GFS2: Userland expects quota limit/warn/usage in 512b blocksAbhijith Das
Userland programs using the quotactl() syscall assume limit/warn/usage block counts in 512b basic blocks which were instead being read/written in fs blocksize in gfs2. With this patch, gfs2 correctly interacts with the syscall using 512b blocks. Signed-off-by: Abhi Das <adas@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-15GFS2: Fix inode deallocation raceSteven Whitehouse
This area of the code has always been a bit delicate due to the subtleties of lock ordering. The problem is that for "normal" alloc/dealloc, we always grab the inode locks first and the rgrp lock later. In order to ensure no races in looking up the unlinked, but still allocated inodes, we need to hold the rgrp lock when we do the lookup, which means that we can't take the inode glock. The solution is to borrow the technique already used by NFS to solve what is essentially the same problem (given an inode number, look up the inode carefully, checking that it really is in the expected state). We cannot do that directly from the allocation code (lock ordering again) so we give the job to the pre-existing delete workqueue and carry on with the allocation as normal. If we find there is no space, we do a journal flush (required anyway if space from a deallocation is to be released) which should block against the pending deallocations, so we should always get the space back. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2010-11-13block: clean up blkdev_get() wrappers and their usersTejun Heo
After recent blkdev_get() modifications, open_by_devnum() and open_bdev_exclusive() are simple wrappers around blkdev_get(). Replace them with blkdev_get_by_dev() and blkdev_get_by_path(). blkdev_get_by_dev() is identical to open_by_devnum(). blkdev_get_by_path() is slightly different in that it doesn't automatically add %FMODE_EXCL to @mode. All users are converted. Most conversions are mechanical and don't introduce any behavior difference. There are several exceptions. * btrfs now sets FMODE_EXCL in btrfs_device->mode, so there's no reason to OR it explicitly on blkdev_put(). * gfs2, nilfs2 and the generic mount_bdev() now set FMODE_EXCL in sb->s_mode. * With the above changes, sb->s_mode now always should contain FMODE_EXCL. WARN_ON_ONCE() added to kill_block_super() to detect errors. The new blkdev_get_*() functions are with proper docbook comments. While at it, add function description to blkdev_get() too. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Neil Brown <neilb@suse.de> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Joern Engel <joern@lazybastard.org> Cc: Chris Mason <chris.mason@oracle.com> Cc: Jan Kara <jack@suse.cz> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: reiserfs-devel@vger.kernel.org Cc: xfs-masters@oss.sgi.com Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13block: make blkdev_get/put() handle exclusive accessTejun Heo
Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-10-31locks: let the caller free file_lock on ->setlease failureChristoph Hellwig
The caller allocated it, the caller should free it. The only issue so far is that we could change the flp pointer even on an error return if the fl_change callback failed. But we can simply move the flp assignment after the fl_change invocation, as the callers don't care about the flp return value if the setlease call failed. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-30locks: fix setlease methods to free passed-in lockJ. Bruce Fields
We modified setlease to require the caller to allocate the new lease in the case of creating a new lease, but forgot to fix up the filesystem methods. Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Steve French <sfrench@samba.org> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>