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* fs/super.c: add lockdep annotation to s_umountPeter Zijlstra2009-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* async: Rename _special -> _domain for clarity.Cornelia Huck2009-02-08
| | | | | | | | | 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>
* [CVE-2009-0029] System call wrappers part 11Heiko Carstens2009-01-14
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* Merge branch 'for_linus' of ↵Linus Torvalds2009-01-08
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * add releasepage hooks to block devices which can be used by file systemsTheodore Ts'o2009-01-03
| | | | | | | | | | | | | | | | | | 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>
* | async: Don't call async_synchronize_full_special() while holding sb_lockDave Kleikamp2009-01-08
| | | | | | | | | | | | | | | | | | | | | | 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>
* | async: make the final inode deletion an asynchronous eventArjan van de Ven2009-01-07
|/ | | | | | | 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>
* security: pass mount flags to security_sb_kern_mount()James Morris2008-12-19
| | | | | | | | 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>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdevLinus Torvalds2008-10-23
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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 ...
| * [PATCH] propagate mode through open_bdev_excl/close_bdev_exclAl Viro2008-10-21
| | | | | | | | | | | | | | 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>
* | [PATCH 2/2] anondev: switch to IDAAlexey Dobriyan2008-10-23
| | | | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* | [PATCH 1/2] anondev: init IDR staticallyAlexey Dobriyan2008-10-23
|/ | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
* fix soft lock up at NFS mount via per-SB LRU-list of unused dentriesKentaro Makita2008-07-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [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>
* make __put_super() staticAdrian Bunk2008-04-29
| | | | | | | | 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>
* quota: quota core changes for quotaon on remountJan Kara2008-04-28
| | | | | | | | | | | | | 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>
* [PATCH] move a bunch of declarations to fs/internal.hAl Viro2008-04-21
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] r/o bind mounts: debugging for missed callsDave Hansen2008-04-19
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] r/o bind mounts: drop write during emergency remountDave Hansen2008-04-19
| | | | | | | | | | | | | | | 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2008-03-25
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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()
| * [PATCH] restore export of do_kern_mount()Al Viro2008-03-17
| | | | | | | | | | | | | | | | | | 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>
* | fs: fix kernel-doc notation warningsRandy Dunlap2008-03-19
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* LSM/SELinux: Interfaces to allow FS to control mount optionsEric Paris2008-03-05
| | | | | | | | | | | | | | | | | | 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>
* quota: turn quotas off when remounting read-onlyJan Kara2008-02-08
| | | | | | | | | | | | Turn off quotas before filesystem is remounted read only. Otherwise quota will try to write to read-only filesystem which does no good... We could also just refuse to remount ro when quota is enabled but turning quota off is consistent with what we do on umount. Signed-off-by: Jan Kara <jack@suse.cz> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mount options: add generic_show_options()Miklos Szeredi2008-02-08
| | | | | | | | | | | | | | | | Add a new s_options field to struct super_block. Filesystems can save mount options passed to them in mount or remount. It is automatically freed when the superblock is destroyed. A new helper function, generic_show_options() is introduced, which uses this field to display the mount options in /proc/mounts. Another helper function, save_mount_options() may be used by filesystems to save the options in the super block. 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>
* Convert files to UTF-8 and some cleanupsJan Engelhardt2007-10-19
| | | | | | | | | | | | | | | | | | * Convert files to UTF-8. * Also correct some people's names (one example is Eißfeldt, which was found in a source file. Given that the author used an ß at all in a source file indicates that the real name has in fact a 'ß' and not an 'ss', which is commonly used as a substitute for 'ß' when limited to 7bit.) * Correct town names (Goettingen -> Göttingen) * Update Eberhard Mönkeberg's address (http://lkml.org/lkml/2007/1/8/313) Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Signed-off-by: Adrian Bunk <bunk@kernel.org>
* Fix misspellings of "system", "controller", "interrupt" and "necessary".Robert P. J. Day2007-10-19
| | | | | | | | Fix the various misspellings of "system", controller", "interrupt" and "[un]necessary". Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
* pid namespaces: introduce MS_KERNMOUNT flagPavel Emelyanov2007-10-19
| | | | | | | | | | | | | | | | | | | | This flag tells the .get_sb callback that this is a kern_mount() call so that it can trust *data pointer to be valid in-kernel one. If this flag is passed from the user process, it is cleared since the *data pointer is not a valid kernel object. Running a few steps forward - this will be needed for proc to create the superblock and store a valid pid namespace on it during the namespace creation. The reason, why the namespace cannot live without proc mount is described in the appropriate patch. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/super.c: use list_for_each_entry() instead of list_for_each()Matthias Kaehlcke2007-10-19
| | | | | | | | | | fs/super.c: use list_for_each_entry() instead of list_for_each() in sget() [akpm@linux-foundation.org: clean up some crap while we're there] Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* put declaration of put_filesystem() in fs.hMiklos Szeredi2007-10-19
| | | | | | | | | | Declarations go into headers. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Ram Pai <linuxram@us.ibm.com> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* writeback: fix periodic superblock dirty inode flushingKen Chen2007-10-17
| | | | | | | | | | | | | | | | | | | | | | | | | Current -mm tree has bucketful of bug fixes in periodic writeback path. However, we still hit a glitch where dirty pages on a given inode aren't completely flushed to the disk, and system will accumulate large amount of dirty pages beyond what dirty_expire_interval is designed for. The problem is __sync_single_inode() will move an inode to sb->s_dirty list even when there are more pending dirty pages on that inode. If there is another inode with a small number of dirty pages, we hit a case where the loop iteration in wb_kupdate() terminates prematurely because wbc.nr_to_write > 0. Thus leaving the inode that has large amount of dirty pages behind and it has to wait for another dirty_writeback_interval before we flush it again. We effectively only write out MAX_WRITEBACK_PAGES every dirty_writeback_interval. If the rate of dirtying is sufficiently high, the system will start accumulate a large number of dirty pages. So fix it by having another sb->s_more_io list on which to park the inode while we iterate through sb->s_io and to allow each dirty inode which resides on that sb to have an equal chance of flushing some amount of dirty pages. Signed-off-by: Ken Chen <kenchen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlbfs: handle empty options stringLee Schermerhorn2007-07-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I was seeing a null pointer deref in fs/super.c:vfs_kern_mount(). Some file system get_sb() handler was returning NULL mnt_sb with a non-negative return value. I also noticed a "hugetlbfs: Bad mount option:" message in the log. Turns out that hugetlbfs_parse_options() was not checking for an empty option string after call to strsep(). On failure, hugetlbfs_parse_options() returns 1. hugetlbfs_fill_super() just passed this return code back up the call stack where vfs_kern_mount() missed the error and proceeded with a NULL mnt_sb. Apparently introduced by patch: hugetlbfs-use-lib-parser-fix-docs.patch The problem was exposed by this line in my fstab: none /huge hugetlbfs defaults 0 0 It can also be demonstrated by invoking mount of hugetlbfs directly with no options or a bogus option. This patch: 1) adds the check for empty option to hugetlbfs_parse_options(), 2) enhances the error message to bracket any unrecognized option with quotes , 3) modifies hugetlbfs_parse_options() to return -EINVAL on any unrecognized option, 4) adds a BUG_ON() to vfs_kern_mount() to catch any get_sb() handler that returns a NULL mnt->mnt_sb with a return value >= 0. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Acked-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>
* add filesystem subtype supportMiklos Szeredi2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a slight problem with filesystem type representation in fuse based filesystems. From the kernel's view, there are just two filesystem types: fuse and fuseblk. From the user's view there are lots of different filesystem types. The user is not even much concerned if the filesystem is fuse based or not. So there's a conflict of interest in how this should be represented in fstab, mtab and /proc/mounts. The current scheme is to encode the real filesystem type in the mount source. So an sshfs mount looks like this: sshfs#user@server:/ /mnt/server fuse rw,nosuid,nodev,... This url-ish syntax works OK for sshfs and similar filesystems. However for block device based filesystems (ntfs-3g, zfs) it doesn't work, since the kernel expects the mount source to be a real device name. A possibly better scheme would be to encode the real type in the type field as "type.subtype". So fuse mounts would look like this: /dev/hda1 /mnt/windows fuseblk.ntfs-3g rw,... user@server:/ /mnt/server fuse.sshfs rw,nosuid,nodev,... This patch adds the necessary code to the kernel so that this can be correctly displayed in /proc/mounts. 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>
* the overdue removal of the mount/umount ueventsAdrian Bunk2007-04-27
| | | | | | | | This patch contains the overdue removal of the mount/umount uevents. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Mark struct super_operations constJosef 'Jeff' Sipek2007-02-12
| | | | | | | | | | | This patch is inspired by Arjan's "Patch series to mark struct file_operations and struct inode_operations const". Compile tested with gcc & sparse. Signed-off-by: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Revert bd_mount_mutex back to a semaphoreDavid Chinner2007-01-11
| | | | | | | | | | | | | Revert bd_mount_mutex back to a semaphore so that xfs_freeze -f /mnt/newtest; xfs_freeze -u /mnt/newtest works safely and doesn't produce lockdep warnings. (XFS unlocks the semaphore from a different task, by design. The mutex code warns about this) Signed-off-by: Dave Chinner <dgc@sgi.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VFS: change struct file to use struct pathJosef "Jeff" Sipek2006-12-08
| | | | | | | | | | | | | This patch changes struct file to use struct path instead of having independent pointers to struct dentry and struct vfsmount, and converts all users of f_{dentry,vfsmnt} in fs/ to use f_path.{dentry,mnt}. Additionally, it adds two #define's to make the transition easier for users of the f_dentry and f_vfsmnt. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] severing fs.h, radix-tree.h -> sched.hAl Viro2006-12-04
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] VFS: Destroy the dentries contributed by a superblock on unmountingDavid Howells2006-10-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The attached patch destroys all the dentries attached to a superblock in one go by: (1) Destroying the tree rooted at s_root. (2) Destroying every entry in the anon list, one at a time. (3) Each entry in the anon list has its subtree consumed from the leaves inwards. This reduces the amount of work generic_shutdown_super() does, and avoids iterating through the dentry_unused list. Note that locking is almost entirely absent in the shrink_dcache_for_umount*() functions added by this patch. This is because: (1) at the point the filesystem calls generic_shutdown_super(), it is not permitted to further touch the superblock's set of dentries, and nor may it remove aliases from inodes; (2) the dcache memory shrinker now skips dentries that are being unmounted; and (3) the superblock no longer has any external references through which the VFS can reach it. Given these points, the only locking we need to do is when we remove dentries from the unused list and the name hashes, which we do a directory's worth at a time. We also don't need to guard against reference counts going to zero unexpectedly and removing bits of the tree we're working on as nothing else can call dput(). A cut down version of dentry_iput() has been folded into shrink_dcache_for_umount_subtree() function. Apart from not needing to unlock things, it also doesn't need to check for inotify watches. In this version of the patch, the complaint about a dentry still being in use has been expanded from a single BUG_ON() and now gives much more information. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: NeilBrown <neilb@suse.de> Acked-by: Ian Kent <raven@themaw.net> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] BLOCK: Make it possible to disable the block layer [try #6]David Howells2006-09-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make it possible to disable the block layer. Not all embedded devices require it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require the block layer to be present. This patch does the following: (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev support. (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls an item that uses the block layer. This includes: (*) Block I/O tracing. (*) Disk partition code. (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS. (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the block layer to do scheduling. Some drivers that use SCSI facilities - such as USB storage - end up disabled indirectly from this. (*) Various block-based device drivers, such as IDE and the old CDROM drivers. (*) MTD blockdev handling and FTL. (*) JFFS - which uses set_bdev_super(), something it could avoid doing by taking a leaf out of JFFS2's book. (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is, however, still used in places, and so is still available. (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and parts of linux/fs.h. (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK. (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK. (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK is not enabled. (*) fs/no-block.c is created to hold out-of-line stubs and things that are required when CONFIG_BLOCK is not set: (*) Default blockdev file operations (to give error ENODEV on opening). (*) Makes some /proc changes: (*) /proc/devices does not list any blockdevs. (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK. (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK. (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if given command other than Q_SYNC or if a special device is specified. (*) In init/do_mounts.c, no reference is made to the blockdev routines if CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2. (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return error ENOSYS by way of cond_syscall if so). (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if CONFIG_BLOCK is not set, since they can't then happen. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* [PATCH] BLOCK: Move functions out of buffer code [try #6]David Howells2006-09-30
| | | | | | | | | | | | | | | | | | | | | | | | | Move some functions out of the buffering code that aren't strictly buffering specific. This is a precursor to being able to disable the block layer. (*) Moved some stuff out of fs/buffer.c: (*) The file sync and general sync stuff moved to fs/sync.c. (*) The superblock sync stuff moved to fs/super.c. (*) do_invalidatepage() moved to mm/truncate.c. (*) try_to_release_page() moved to mm/filemap.c. (*) Moved some related declarations between header files: (*) declarations for do_invalidatepage() and try_to_release_page() moved to linux/mm.h. (*) __set_page_dirty_buffers() moved to linux/buffer_head.h. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* [PATCH] fs: add lock annotation to grab_superJosh Triplett2006-09-29
| | | | | | | | | | | grab_super gets called with sb_lock held, and releases it. Add a lock annotation to this function so that sparse can check callers for lock pairing, and so that sparse will not complain about this function since it intentionally uses the lock in this manner. Signed-off-by: Josh Triplett <josh@freedesktop.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] add missing desctiption in super.cHenrik Kretzschmar2006-09-06
| | | | | | | | Adds kernel-doc for alloc_super() type in fs/super.c. Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: annotate sb ->s_umountArjan van de Ven2006-07-03
| | | | | | | | | | | | | The s_umount rwsem needs to be classified as per-superblock since it's perfectly legit to keep multiple of those recursively in the VFS locking rules. Has no effect on non-lockdep kernels. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lockdep: annotate ->s_lockIngo Molnar2006-07-03
| | | | | | | | | | | Teach special (per-filesystem) locking code to the lock validator. Minimal effect on non-lockdep kernels: one extra parameter to alloc_super(). Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Merge branch 'master' of /home/trondmy/kernel/linux-2.6/Trond Myklebust2006-06-24
|\ | | | | | | | | | | | | | | | | | | Conflicts: fs/nfs/inode.c fs/super.c Fix conflicts between patch 'NFS: Split fs/nfs/inode.c' and patch 'VFS: Permit filesystem to override root dentry on mount'
| * [PATCH] VFS: Permit filesystem to perform statfs with a known root dentryDavid Howells2006-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Give the statfs superblock operation a dentry pointer rather than a superblock pointer. This complements the get_sb() patch. That reduced the significance of sb->s_root, allowing NFS to place a fake root there. However, NFS does require a dentry to use as a target for the statfs operation. This permits the root in the vfsmount to be used instead. linux/mount.h has been added where necessary to make allyesconfig build successfully. Interest has also been expressed for use with the FUSE and XFS filesystems. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| * [PATCH] VFS: Permit filesystem to override root dentry on mountDavid Howells2006-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| * [PATCH] Fix dcache race during umountNeilBrown2006-06-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The race is that the shrink_dcache_memory shrinker could get called while a filesystem is being unmounted, and could try to prune a dentry belonging to that filesystem. If it does, then it will call in to iput on the inode while the dentry is no longer able to be found by the umounting process. If iput takes a while, generic_shutdown_super could get all the way though shrink_dcache_parent and shrink_dcache_anon and invalidate_inodes without ever waiting on this particular inode. Eventually the superblock gets freed anyway and if the iput tried to touch it (which some filesystems certainly do), it will lose. The promised "Self-destruct in 5 seconds" doesn't lead to a nice day. The race is closed by holding s_umount while calling prune_one_dentry on someone else's dentry. As a down_read_trylock is used, shrink_dcache_memory will no longer try to prune the dentry of a filesystem that is being unmounted, and unmount will not be able to start until any such active prune_one_dentry completes. This requires that prune_dcache *knows* which filesystem (if any) it is doing the prune on behalf of so that it can be careful of other filesystems. shrink_dcache_memory isn't called it on behalf of any filesystem, and so is careful of everything. shrink_dcache_anon is now passed a super_block rather than the s_anon list out of the superblock, so it can get the s_anon list itself, and can pass the superblock down to prune_dcache. If prune_dcache finds a dentry that it cannot free, it leaves it where it is (at the tail of the list) and exits, on the assumption that some other thread will be removing that dentry soon. To try to make sure that some work gets done, a limited number of dnetries which are untouchable are skipped over while choosing the dentry to work on. I believe this race was first found by Kirill Korotaev. Cc: Jan Blunck <jblunck@suse.de> Acked-by: Kirill Korotaev <dev@openvz.org> Cc: Olaf Hering <olh@suse.de> Acked-by: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Balbir Singh <balbir@in.ibm.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | VFS: Unexport do_kern_mount() and clean up simple_pin_fs()Trond Myklebust2006-06-09
| | | | | | | | | | | | | | Replace all module uses with the new vfs_kern_mount() interface, and fix up simple_pin_fs(). Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
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