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path: root/fs/super.c
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2009-06-17remove unlock_kernel() left accidentallyJ. R. Okajima
commit 337eb00a2c3a421999c39c94ce7e33545ee8baa7 Push BKL down into ->remount_fs() and commit 4aa98cf768b6f2ea4b204620d949a665959214f6 Push BKL down into do_remount_sb() were uncorrectly merged. The former removes one pair of lock/unlock_kernel(), but the latter adds several unlock_kernel(). Finally a few unlock_kernel() calls left. Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11Push BKL down into ->remount_fs()Alessio Igor Bogani
[xfs, btrfs, capifs, shmem don't need BKL, exempt] Signed-off-by: Alessio Igor Bogani <abogani@texware.it> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11->write_super lock_super pushdownChristoph Hellwig
Push down lock_super into ->write_super instances and remove it from the caller. Following filesystem don't need ->s_lock in ->write_super and are skipped: * bfs, nilfs2 - no other uses of s_lock and have internal locks in ->write_super * ext2 - uses BKL in ext2_write_super and has internal calls without s_lock * reiserfs - no other uses of s_lock as has reiserfs_write_lock (BKL) in ->write_super * xfs - no other uses of s_lock and uses internal lock (buffer lock on superblock buffer) to serialize ->write_super. Also xfs_fs_write_super is superflous and will go away in the next merge window Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11Push BKL down into do_remount_sb()Al Viro
[folded fix from Jiri Slaby] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11Push lock_super() into the ->remount_fs() of filesystems that care about itAl Viro
Note that since we can't run into contention between remount_fs and write_super (due to exclusion on s_umount), we have to care only about filesystems that touch lock_super() on their own. Out of those ext3, ext4, hpfs, sysv and ufs do need it; fat doesn't since its ->remount_fs() only accesses assign-once data (basically, it's "we have no atime on directories and only have atime on files for vfat; force nodiratime and possibly noatime into *flags"). [folded a build fix from hch] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11push BKL down into ->put_superChristoph Hellwig
Move BKL into ->put_super from the only caller. A couple of filesystems had trivial enough ->put_super (only kfree and NULLing of s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs, hugetlbfs, omfs, qnx4, shmem, all others got the full treatment. Most of them probably don't need it, but I'd rather sort that out individually. Preferably after all the other BKL pushdowns in that area. [AV: original used to move lock_super() down as well; these changes are removed since we don't do lock_super() at all in generic_shutdown_super() now] [AV: fuse, btrfs and xfs are known to need no damn BKL, exempt] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11No need to do lock_super() for exclusion in generic_shutdown_super()Al Viro
We can't run into contention on it. All other callers of lock_super() either hold s_umount (and we have it exclusive) or hold an active reference to superblock in question, which prevents the call of generic_shutdown_super() while the reference is held. So we can replace lock_super(s) with get_fs_excl() in generic_shutdown_super() (and corresponding change for unlock_super(), of course). Since ext4 expects s_lock held for its put_super, take lock_super() into it. The rest of filesystems do not care at all. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11Make sure that all callers of remount hold s_umount exclusiveAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11cleanup sync_supersChristoph Hellwig
Merge the write_super helper into sync_super and move the check for ->write_super earlier so that we can avoid grabbing a reference to a superblock that doesn't have it. While we're at it also add a little comment documenting sync_supers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11remove ->write_super call in generic_shutdown_superChristoph Hellwig
We just did a full fs writeout using sync_filesystem before, and if that's not enough for the filesystem it can perform it's own writeout in ->put_super, which many filesystems already do. Move a call to foofs_write_super into every foofs_put_super for now to guarantee identical behaviour until it's cleaned up by the individual filesystem maintainers. Exceptions: - affs already has identical copy & pasted code at the beginning of affs_put_super so no need to do it twice. - xfs does the right thing without it and I have changes pending for the xfs tree touching this are so I don't really need conflicts here.. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11vfs: Rename fsync_super() to sync_filesystem() (version 4)Jan Kara
Rename the function so that it better describe what it really does. Also remove the unnecessary include of buffer_head.h. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11vfs: Move syncing code from super.c to sync.c (version 4)Jan Kara
Move sync_filesystems(), __fsync_super(), fsync_super() from super.c to sync.c where it fits better. [build fixes folded] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11vfs: Make sys_sync() use fsync_super() (version 4)Jan Kara
It is unnecessarily fragile to have two places (fsync_super() and do_sync()) doing data integrity sync of the filesystem. Alter __fsync_super() to accommodate needs of both callers and use it. So after this patch __fsync_super() is the only place where we gather all the calls needed to properly send all data on a filesystem to disk. Nice bonus is that we get a complete livelock avoidance and write_supers() is now only used for periodic writeback of superblocks. sync_blockdevs() introduced a couple of patches ago is gone now. [build fixes folded] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11vfs: Make __fsync_super() a static function (version 4)Jan Kara
__fsync_super() does the same thing as fsync_super(). So change the only caller to use fsync_super() and make __fsync_super() static. This removes unnecessarily duplicated call to sync_blockdev() and prepares ground for the changes to __fsync_super() in the following patches. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11vfs: Call ->sync_fs() even if s_dirt is 0 (version 4)Jan Kara
sync_filesystems() has a condition that if wait == 0 and s_dirt == 0, then ->sync_fs() isn't called. This does not really make much sence since s_dirt is generally used by a filesystem to mean that ->write_super() needs to be called. But ->sync_fs() does different things. I even suspect that some filesystems (btrfs?) sets s_dirt just to fool this logic. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11vfs: Fix sys_sync() and fsync_super() reliability (version 4)Jan Kara
So far, do_sync() called: sync_inodes(0); sync_supers(); sync_filesystems(0); sync_filesystems(1); sync_inodes(1); This ordering makes it kind of hard for filesystems as sync_inodes(0) need not submit all the IO (for example it skips inodes with I_SYNC set) so e.g. forcing transaction to disk in ->sync_fs() is not really enough. Therefore sys_sync has not been completely reliable on some filesystems (ext3, ext4, reiserfs, ocfs2 and others are hit by this) when racing e.g. with background writeback. A similar problem hits also other filesystems (e.g. ext2) because of write_supers() being called before the sync_inodes(1). Change the ordering of calls in do_sync() - this requires a new function sync_blockdevs() to preserve the property that block devices are always synced after write_super() / sync_fs() call. The same issue is fixed in __fsync_super() function used on umount / remount read-only. [AV: build fixes] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11remove s_async_listChristoph Hellwig
Remove the unused s_async_list in the superblock, a leftover of the broken async inode deletion code that leaked into mainline. Having this in the middle of the sync/unmount path is not helpful for the following cleanups. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11fs: move mark_files_ro into file_table.cnpiggin@suse.de
This function walks the s_files lock, and operates primarily on the files in a superblock, so it better belongs here (eg. see also fs_may_remount_ro). [AV: ... and it shouldn't be static after that move] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09NULL noise in fs/super.c:kill_bdev_super()H Hartley Sweeten
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Subrata Modak <subrata@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09New helper: deactivate_locked_super()Al Viro
Does equivalent of up_write(&s->s_umount); deactivate_super(s); However, it does not does not unlock it until it's all over. As the result, it's safe to use to dispose of new superblock on ->get_sb() failure exits - nobody will see the sucker until it's all over. Equivalent using up_write/deactivate_super is safe for that purpose if superblock is either safe to use or has NULL ->s_root when we unlock. Normally filesystems take the required precautions, but a) we do have bugs in that area in some of them. b) up_write/deactivate_super sequence is extremely common, so the helper makes sense anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-07namespaces: move proc_net_get_sb to a generic fs/super.c helperSerge E. Hallyn
The mqueuefs filesystem will use this helper as well. Proc's main get_sb could also be made to use it, but that will require a bit more rework. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-03CacheFiles: Export things for CacheFilesDavid Howells
Export a number of functions for CacheFiles's use. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-03-27Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (37 commits) fs: avoid I_NEW inodes Merge code for single and multiple-instance mounts Remove get_init_pts_sb() Move common mknod_ptmx() calls into caller Parse mount options just once and copy them to super block Unroll essentials of do_remount_sb() into devpts vfs: simple_set_mnt() should return void fs: move bdev code out of buffer.c constify dentry_operations: rest constify dentry_operations: configfs constify dentry_operations: sysfs constify dentry_operations: JFS constify dentry_operations: OCFS2 constify dentry_operations: GFS2 constify dentry_operations: FAT constify dentry_operations: FUSE constify dentry_operations: procfs constify dentry_operations: ecryptfs constify dentry_operations: CIFS constify dentry_operations: AFS ...
2009-03-27Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6: (27 commits) ext2: Zero our b_size in ext2_quota_read() trivial: fix typos/grammar errors in fs/Kconfig quota: Coding style fixes quota: Remove superfluous inlines quota: Remove uppercase aliases for quota functions. nfsd: Use lowercase names of quota functions jfs: Use lowercase names of quota functions udf: Use lowercase names of quota functions ufs: Use lowercase names of quota functions reiserfs: Use lowercase names of quota functions ext4: Use lowercase names of quota functions ext3: Use lowercase names of quota functions ext2: Use lowercase names of quota functions ramfs: Remove quota call vfs: Use lowercase names of quota functions quota: Remove dqbuf_t and other cleanups quota: Remove NODQUOT macro quota: Make global quota locks cacheline aligned quota: Move quota files into separate directory ext4: quota reservation for delayed allocation ...
2009-03-27vfs: simple_set_mnt() should return voidSukadev Bhattiprolu
simple_set_mnt() is defined as returning 'int' but always returns 0. Callers assume simple_set_mnt() never fails and don't properly cleanup if it were to _ever_ fail. For instance, get_sb_single() and get_sb_nodev() should: up_write(sb->s_unmount); deactivate_super(sb); if simple_set_mnt() fails. Since simple_set_mnt() never fails, would be cleaner if it did not return anything. [akpm@linux-foundation.org: fix build] Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-26Get rid of pdflush_operation() in emergency sync and remountJens Axboe
Opencode a cheasy approach with kevent. The idea here is that we'll add some generic delayed work infrastructure, which probably wont be based on pdflush (or maybe it will, in which case we can just add it back). This is in preparation for getting rid of pdflush completely. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-26vfs: Use lowercase names of quota functionsJan Kara
Use lowercase names of quota functions instead of old uppercase ones. Signed-off-by: Jan Kara <jack@suse.cz> CC: Alexander Viro <viro@zeniv.linux.org.uk>
2009-03-12vfs: add missing unlock in sget()Li Zefan
In sget(), destroy_super(s) is called with s->s_umount held, which makes lockdep unhappy. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18fs/super.c: add lockdep annotation to s_umountPeter Zijlstra
Li Zefan said: Thread 1: for ((; ;)) { mount -t cpuset xxx /mnt > /dev/null 2>&1 cat /mnt/cpus > /dev/null 2>&1 umount /mnt > /dev/null 2>&1 } Thread 2: for ((; ;)) { mount -t cpuset xxx /mnt > /dev/null 2>&1 umount /mnt > /dev/null 2>&1 } (Note: It is irrelevant which cgroup subsys is used.) After a while a lockdep warning showed up: ============================================= [ INFO: possible recursive locking detected ] 2.6.28 #479 --------------------------------------------- mount/13554 is trying to acquire lock: (&type->s_umount_key#19){--..}, at: [<c049d888>] sget+0x5e/0x321 but task is already holding lock: (&type->s_umount_key#19){--..}, at: [<c049da0c>] sget+0x1e2/0x321 other info that might help us debug this: 1 lock held by mount/13554: #0: (&type->s_umount_key#19){--..}, at: [<c049da0c>] sget+0x1e2/0x321 stack backtrace: Pid: 13554, comm: mount Not tainted 2.6.28-mc #479 Call Trace: [<c044ad2e>] validate_chain+0x4c6/0xbbd [<c044ba9b>] __lock_acquire+0x676/0x700 [<c044bb82>] lock_acquire+0x5d/0x7a [<c049d888>] ? sget+0x5e/0x321 [<c061b9b8>] down_write+0x34/0x50 [<c049d888>] ? sget+0x5e/0x321 [<c049d888>] sget+0x5e/0x321 [<c045a2e7>] ? cgroup_set_super+0x0/0x3e [<c045959f>] ? cgroup_test_super+0x0/0x2f [<c045bcea>] cgroup_get_sb+0x98/0x2e7 [<c045cfb6>] cpuset_get_sb+0x4a/0x5f [<c049dfa4>] vfs_kern_mount+0x40/0x7b [<c049e02d>] do_kern_mount+0x37/0xbf [<c04af4a0>] do_mount+0x5c3/0x61a [<c04addd2>] ? copy_mount_options+0x2c/0x111 [<c04af560>] sys_mount+0x69/0xa0 [<c0403251>] sysenter_do_call+0x12/0x31 The cause is after alloc_super() and then retry, an old entry in list fs_supers is found, so grab_super(old) is called, but both functions hold s_umount lock: struct super_block *sget(...) { ... retry: spin_lock(&sb_lock); if (test) { list_for_each_entry(old, &type->fs_supers, s_instances) { if (!test(old, data)) continue; if (!grab_super(old)) <--- 2nd: down_write(&old->s_umount); goto retry; if (s) destroy_super(s); return old; } } if (!s) { spin_unlock(&sb_lock); s = alloc_super(type); <--- 1th: down_write(&s->s_umount) if (!s) return ERR_PTR(-ENOMEM); goto retry; } ... } It seems like a false positive, and seems like VFS but not cgroup needs to be fixed. Peter said: We can simply put the new s_umount instance in a but lockdep doesn't particularly cares about subclass order. If there's any issue with the callers of sget() assuming the s_umount lock being of sublcass 0, then there is another annotation we can use to fix that, but lets not bother with that if this is sufficient. Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12673 Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Li Zefan <lizf@cn.fujitsu.com> Reported-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Paul Menage <menage@google.com> Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-08async: Rename _special -> _domain for clarity.Cornelia Huck
Rename the async_*_special() functions to async_*_domain(), which describes the purpose of these functions much better. [Broke up long lines to silence checkpatch] Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-14[CVE-2009-0029] System call wrappers part 11Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-08Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (57 commits) jbd2: Fix oops in jbd2_journal_init_inode() on corrupted fs ext4: Remove "extents" mount option block: Add Kconfig help which notes that ext4 needs CONFIG_LBD ext4: Make printk's consistently prefixed with "EXT4-fs: " ext4: Add sanity checks for the superblock before mounting the filesystem ext4: Add mount option to set kjournald's I/O priority jbd2: Submit writes to the journal using WRITE_SYNC jbd2: Add pid and journal device name to the "kjournald2 starting" message ext4: Add markers for better debuggability ext4: Remove code to create the journal inode ext4: provide function to release metadata pages under memory pressure ext3: provide function to release metadata pages under memory pressure add releasepage hooks to block devices which can be used by file systems ext4: Fix s_dirty_blocks_counter if block allocation failed with nodelalloc ext4: Init the complete page while building buddy cache ext4: Don't allow new groups to be added during block allocation ext4: mark the blocks/inode bitmap beyond end of group as used ext4: Use new buffer_head flag to check uninit group bitmaps initialization ext4: Fix the race between read_inode_bitmap() and ext4_new_inode() ext4: code cleanup ...
2009-01-08async: Don't call async_synchronize_full_special() while holding sb_lockDave Kleikamp
sync_filesystems() shouldn't be calling async_synchronize_full_special while holding a spinlock. The second while loop in that function is the right place for this anyway. Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Reported-by: Grissiom <chaos.proton@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-07async: make the final inode deletion an asynchronous eventArjan van de Ven
this makes "rm -rf" on a (names cached) kernel tree go from 11.6 to 8.6 seconds on an ext3 filesystem Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-03add releasepage hooks to block devices which can be used by file systemsTheodore Ts'o
Implement blkdev_releasepage() to release the buffer_heads and pages after we release private data belonging to a mounted filesystem. Cc: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-12-20security: pass mount flags to security_sb_kern_mount()James Morris
Pass mount flags to security_sb_kern_mount(), so security modules can determine if a mount operation is being performed by the kernel. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2008-10-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdevLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev: (66 commits) [PATCH] kill the rest of struct file propagation in block ioctls [PATCH] get rid of struct file use in blkdev_ioctl() BLKBSZSET [PATCH] get rid of blkdev_locked_ioctl() [PATCH] get rid of blkdev_driver_ioctl() [PATCH] sanitize blkdev_get() and friends [PATCH] remember mode of reiserfs journal [PATCH] propagate mode through swsusp_close() [PATCH] propagate mode through open_bdev_excl/close_bdev_excl [PATCH] pass fmode_t to blkdev_put() [PATCH] kill the unused bsize on the send side of /dev/loop [PATCH] trim file propagation in block/compat_ioctl.c [PATCH] end of methods switch: remove the old ones [PATCH] switch sr [PATCH] switch sd [PATCH] switch ide-scsi [PATCH] switch tape_block [PATCH] switch dcssblk [PATCH] switch dasd [PATCH] switch mtd_blkdevs [PATCH] switch mmc ...
2008-10-23[PATCH 2/2] anondev: switch to IDAAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-23[PATCH 1/2] anondev: init IDR staticallyAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-21[PATCH] propagate mode through open_bdev_excl/close_bdev_exclAl Viro
replace open_bdev_excl/close_bdev_excl with variants taking fmode_t. superblock gets the value used to mount it stored in sb->s_mode Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-24fix soft lock up at NFS mount via per-SB LRU-list of unused dentriesKentaro Makita
[Summary] Split LRU-list of unused dentries to one per superblock to avoid soft lock up during NFS mounts and remounting of any filesystem. Previously I posted here: http://lkml.org/lkml/2008/3/5/590 [Descriptions] - background dentry_unused is a list of dentries which are not referenced. dentry_unused grows up when references on directories or files are released. This list can be very long if there is huge free memory. - the problem When shrink_dcache_sb() is called, it scans all dentry_unused linearly under spin_lock(), and if dentry->d_sb is differnt from given superblock, scan next dentry. This scan costs very much if there are many entries, and very ineffective if there are many superblocks. IOW, When we need to shrink unused dentries on one dentry, but scans unused dentries on all superblocks in the system. For example, we scan 500 dentries to unmount a filesystem, but scans 1,000,000 or more unused dentries on other superblocks. In our case , At mounting NFS*, shrink_dcache_sb() is called to shrink unused dentries on NFS, but scans 100,000,000 unused dentries on superblocks in the system such as local ext3 filesystems. I hear NFS mounting took 1 min on some system in use. * : NFS uses virtual filesystem in rpc layer, so NFS is affected by this problem. 100,000,000 is possible number on large systems. Per-superblock LRU of unused dentried can reduce the cost in reasonable manner. - How to fix I found this problem is solved by David Chinner's "Per-superblock unused dentry LRU lists V3"(1), so I rebase it and add some fix to reclaim with fairness, which is in Andrew Morton's comments(2). 1) http://lkml.org/lkml/2006/5/25/318 2) http://lkml.org/lkml/2006/5/25/320 Split LRU-list of unused dentries to each superblocks. Then, NFS mounting will check dentries under a superblock instead of all. But this spliting will break LRU of dentry-unused. So, I've attempted to make reclaim unused dentrins with fairness by calculate number of dentries to scan on this sb based on following way number of dentries to scan on this sb = count * (number of dentries on this sb / number of dentries in the machine) - ToDo - I have to measuring performance number and do stress tests. - When unmount occurs during prune_dcache(), scanning on same superblock, It is unable to reach next superblock because it is gone away. We restart scannig superblock from first one, it causes unfairness of reclaim unused dentries on first superblock. But I think this happens very rarely. - Test Results Result on 6GB boxes with excessive unused dentries. Without patch: $ cat /proc/sys/fs/dentry-state 10181835 10180203 45 0 0 0 # mount -t nfs 10.124.60.70:/work/kernel-src nfs real 0m1.830s user 0m0.001s sys 0m1.653s With this patch: $ cat /proc/sys/fs/dentry-state 10236610 10234751 45 0 0 0 # mount -t nfs 10.124.60.70:/work/kernel-src nfs real 0m0.106s user 0m0.002s sys 0m0.032s [akpm@linux-foundation.org: fix comments] Signed-off-by: Kentaro Makita <k-makita@np.css.fujitsu.com> Cc: Neil Brown <neilb@suse.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: David Chinner <dgc@sgi.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29make __put_super() staticAdrian Bunk
Make the needlessly global __put_super() static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28quota: quota core changes for quotaon on remountJan Kara
Currently, we just turn quotas off on remount of filesystem to read-only state. The patch below adds necessary framework so that we can turn quotas off on remount RO but we are able to automatically reenable them again when filesystem is remounted to RW state. All we need to do is to keep references to inodes of quota files when remounting RO and using these references to reenable quotas when remounting RW. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-21[PATCH] move a bunch of declarations to fs/internal.hAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19[PATCH] r/o bind mounts: debugging for missed callsDave Hansen
There have been a few oopses caused by 'struct file's with NULL f_vfsmnts. There was also a set of potentially missed mnt_want_write()s from dentry_open() calls. This patch provides a very simple debugging framework to catch these kinds of bugs. It will WARN_ON() them, but should stop us from having any oopses or mnt_writer count imbalances. I'm quite convinced that this is a good thing because it found bugs in the stuff I was working on as soon as I wrote it. [hch: made it conditional on a debug option. But it's still a little bit too ugly] [hch: merged forced remount r/o fix from Dave and akpm's fix for the fix] Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-19[PATCH] r/o bind mounts: drop write during emergency remountDave Hansen
The emergency remount code forcibly removes FMODE_WRITE from filps. The r/o bind mount code notices that this was done without a proper mnt_drop_write() and properly gives a warning. This patch does a mnt_drop_write() to keep everything balanced. Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-03-25Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: [PATCH] get stack footprint of pathname resolution back to relative sanity [PATCH] double iput() on failure exit in hugetlb [PATCH] double dput() on failure exit in tiny-shmem [PATCH] fix up new filp allocators [PATCH] check for null vfsmount in dentry_open() [PATCH] reiserfs: eliminate private use of struct file in xattr [PATCH] sanitize hppfs hppfs pass vfsmount to dentry_open() [PATCH] restore export of do_kern_mount()
2008-03-19fs: fix kernel-doc notation warningsRandy Dunlap
Fix kernel-doc notation warnings in fs/. Warning(mmotm-2008-0314-1449//fs/super.c:560): missing initial short description on line: * mark_files_ro Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line: * lease_get_mtime Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line: * lease_get_mtime Warning(mmotm-2008-0314-1449//fs/namei.c:1368): missing initial short description on line: * lookup_one_len: filesystem helper to lookup single pathname component Warning(mmotm-2008-0314-1449//fs/buffer.c:3221): missing initial short description on line: * bh_uptodate_or_lock: Test whether the buffer is uptodate Warning(mmotm-2008-0314-1449//fs/buffer.c:3240): missing initial short description on line: * bh_submit_read: Submit a locked buffer for reading Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:30): missing initial short description on line: * writeback_acquire: attempt to get exclusive writeback access to a device Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:47): missing initial short description on line: * writeback_in_progress: determine whether there is writeback in progress Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:58): missing initial short description on line: * writeback_release: relinquish exclusive writeback access against a device. Warning(mmotm-2008-0314-1449//include/linux/jbd.h:351): contents before sections Warning(mmotm-2008-0314-1449//include/linux/jbd.h:561): contents before sections Warning(mmotm-2008-0314-1449//fs/jbd/transaction.c:1935): missing initial short description on line: * void journal_invalidatepage() Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-17[PATCH] restore export of do_kern_mount()Al Viro
vfs_kern_mount() requires having a reference to fs type, which makes it impossible for module to create procfs, etc. private mount. Open-coding is not an option, since e.g. put_filesystem() is _not_ exported, and for a good reason. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-03-06LSM/SELinux: Interfaces to allow FS to control mount optionsEric Paris
Introduce new LSM interfaces to allow an FS to deal with their own mount options. This includes a new string parsing function exported from the LSM that an FS can use to get a security data blob and a new security data blob. This is particularly useful for an FS which uses binary mount data, like NFS, which does not pass strings into the vfs to be handled by the loaded LSM. Also fix a BUG() in both SELinux and SMACK when dealing with binary mount data. If the binary mount data is less than one page the copy_page() in security_sb_copy_data() can cause an illegal page fault and boom. Remove all NFSisms from the SELinux code since they were broken by past NFS changes. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>