summaryrefslogtreecommitdiff
path: root/Documentation/filesystems
AgeCommit message (Collapse)Author
2010-01-11proc: partially revert "procfs: provide stack information for threads"KOSAKI Motohiro
Commit d899bf7b (procfs: provide stack information for threads) introduced to show stack information in /proc/{pid}/status. But it cause large performance regression. Unfortunately /proc/{pid}/status is used ps command too and ps is one of most important component. Because both to take mmap_sem and page table walk are heavily operation. If many process run, the ps performance is, [before d899bf7b] % perf stat ps >/dev/null Performance counter stats for 'ps': 4090.435806 task-clock-msecs # 0.032 CPUs 229 context-switches # 0.000 M/sec 0 CPU-migrations # 0.000 M/sec 234 page-faults # 0.000 M/sec 8587565207 cycles # 2099.425 M/sec 9866662403 instructions # 1.149 IPC 3789415411 cache-references # 926.409 M/sec 30419509 cache-misses # 7.437 M/sec 128.859521955 seconds time elapsed [after d899bf7b] % perf stat ps > /dev/null Performance counter stats for 'ps': 4305.081146 task-clock-msecs # 0.028 CPUs 480 context-switches # 0.000 M/sec 2 CPU-migrations # 0.000 M/sec 237 page-faults # 0.000 M/sec 9021211334 cycles # 2095.480 M/sec 10605887536 instructions # 1.176 IPC 3612650999 cache-references # 839.160 M/sec 23917502 cache-misses # 5.556 M/sec 152.277819582 seconds time elapsed Thus, this patch revert it. Fortunately /proc/{pid}/task/{tid}/smaps provide almost same information. we can use it. Commit d899bf7b introduced two features: 1) Add the annotattion of [thread stack: xxxx] mark to /proc/{pid}/task/{tid}/maps. 2) Add StackUsage field to /proc/{pid}/status. I only revert (2), because I haven't seen (1) cause regression. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Stefani Seibold <stefani@seibold.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: nilfs2: update mailing list address nilfs2: Storage class should be before const qualifier nilfs2: trivial coding style fix
2010-01-02nilfs2: update mailing list addressRyusuke Konishi
This replaces the list address for nilfs discussion to linux-nilfs at vger.kernel.org from users at nilfs.org. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-12-24ext4: Update documentation to correct the inode_readahead_blks option nameFang Wenqi
Per commit 240799cd, the option name for readahead should be inode_readahead_blks, not inode_readahead. Signed-off-by: Fang Wenqi <antonf@turbolinux.com.cn> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-12-23Driver core: driver_attribute parameters can often be const*Phil Carmody
Many struct driver_attribute descriptors are purely read-only structures, and there's no need to change them. Therefore make the promise not to, which will let those descriptors be put in a ro section. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-23Driver core: device_attribute parameters can often be const*Phil Carmody
Most device_attributes are const, and are begging to be put in a ro section. However, the create and remove file interfaces were failing to propagate the const promise which the only functions they call offer. Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-16Merge branch 'for-2.6.33' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* 'for-2.6.33' of git://linux-nfs.org/~bfields/linux: (42 commits) nfsd: remove pointless paths in file headers nfsd: move most of nfsfh.h to fs/nfsd nfsd: remove unused field rq_reffh nfsd: enable V4ROOT exports nfsd: make V4ROOT exports read-only nfsd: restrict filehandles accepted in V4ROOT case nfsd: allow exports of symlinks nfsd: filter readdir results in V4ROOT case nfsd: filter lookup results in V4ROOT case nfsd4: don't continue "under" mounts in V4ROOT case nfsd: introduce export flag for v4 pseudoroot nfsd: let "insecure" flag vary by pseudoflavor nfsd: new interface to advertise export features nfsd: Move private headers to source directory vfs: nfsctl.c un-used nfsd #includes lockd: Remove un-used nfsd headers #includes s390: remove un-used nfsd #includes sparc: remove un-used nfsd #includes parsic: remove un-used nfsd #includes compat.c: Remove dependence on nfsd private headers ...
2009-12-16seq_file: use proc_create() in documentationAlexey Dobriyan
Using create_proc_entry() + ->proc_fops assignment is racy because ->proc_fops will be NULL for some time, use proc_create() to avoid race. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15procfs: allow threads to rename siblings via /proc/pid/tasks/tid/commjohn stultz
Setting a thread's comm to be something unique is a very useful ability and is helpful for debugging complicated threaded applications. However currently the only way to set a thread name is for the thread to name itself via the PR_SET_NAME prctl. However, there may be situations where it would be advantageous for a thread dispatcher to be naming the threads its managing, rather then having the threads self-describe themselves. This sort of behavior is available on other systems via the pthread_setname_np() interface. This patch exports a task's comm via proc/pid/comm and proc/pid/task/tid/comm interfaces, and allows thread siblings to write to these values. [akpm@linux-foundation.org: cleanups] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Mike Fulton <fultonm@ca.ibm.com> Cc: Sean Foley <Sean_Foley@ca.ibm.com> Cc: Darren Hart <dvhltc@us.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-11Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (21 commits) ext3: PTR_ERR return of wrong pointer in setup_new_group_blocks() ext3: Fix data / filesystem corruption when write fails to copy data ext4: Support for 64-bit quota format ext3: Support for vfsv1 quota format quota: Implement quota format with 64-bit space and inode limits quota: Move definition of QFMT_OCFS2 to linux/quota.h ext2: fix comment in ext2_find_entry about return values ext3: Unify log messages in ext3 ext2: clear uptodate flag on super block I/O error ext2: Unify log messages in ext2 ext3: make "norecovery" an alias for "noload" ext3: Don't update the superblock in ext3_statfs() ext3: journal all modifications in ext3_xattr_set_handle ext2: Explicitly assign values to on-disk enum of filetypes quota: Fix WARN_ON in lookup_one_len const: struct quota_format_ops ubifs: remove manual O_SYNC handling afs: remove manual O_SYNC handling kill wait_on_page_writeback_range vfs: Implement proper O_SYNC semantics ...
2009-12-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: (49 commits) nilfs2: separate wait function from nilfs_segctor_write nilfs2: add iterator for segment buffers nilfs2: hide nilfs_write_info struct in segment buffer code nilfs2: relocate io status variables to segment buffer nilfs2: do not return io error for bio allocation failure nilfs2: use list_splice_tail or list_splice_tail_init nilfs2: replace mark_inode_dirty as nilfs_mark_inode_dirty nilfs2: delete mark_inode_dirty in nilfs_delete_entry nilfs2: delete mark_inode_dirty in nilfs_commit_chunk nilfs2: change return type of nilfs_commit_chunk nilfs2: split nilfs_unlink as nilfs_do_unlink and nilfs_unlink nilfs2: delete redundant mark_inode_dirty nilfs2: expand inode_inc_link_count and inode_dec_link_count nilfs2: delete mark_inode_dirty from nilfs_set_link nilfs2: delete mark_inode_dirty in nilfs_new_inode nilfs2: add norecovery mount option nilfs2: add helper to get if volume is in a valid state nilfs2: move recovery completion into load_nilfs function nilfs2: apply readahead for recovery on mount nilfs2: clean up get/put function of a segment usage ...
2009-12-10Merge 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: (47 commits) ext4: Fix potential fiemap deadlock (mmap_sem vs. i_data_sem) ext4: Do not override ext2 or ext3 if built they are built as modules jbd2: Export jbd2_log_start_commit to fix ext4 build ext4: Fix insufficient checks in EXT4_IOC_MOVE_EXT ext4: Wait for proper transaction commit on fsync ext4: fix incorrect block reservation on quota transfer. ext4: quota macros cleanup ext4: ext4_get_reserved_space() must return bytes instead of blocks ext4: remove blocks from inode prealloc list on failure ext4: wait for log to commit when umounting ext4: Avoid data / filesystem corruption when write fails to copy data ext4: Use ext4 file system driver for ext2/ext3 file system mounts ext4: Return the PTR_ERR of the correct pointer in setup_new_group_blocks() jbd2: Add ENOMEM checking in and for jbd2_journal_write_metadata_buffer() ext4: remove unused parameter wbc from __ext4_journalled_writepage() ext4: remove encountered_congestion trace ext4: move_extent_per_page() cleanup ext4: initialize moved_len before calling ext4_move_extents() ext4: Fix double-free of blocks with EXT4_IOC_MOVE_EXT ext4: use ext4_data_block_valid() in ext4_free_blocks() ...
2009-12-10ext3: make "norecovery" an alias for "noload"Eric Sandeen
Users on the list recently complained about differences across filesystems w.r.t. how to mount without a journal replay. In the discussion it was noted that xfs's "norecovery" option is perhaps more descriptively accurate than "noload," so let's make that an alias for ext3. Also show this status in /proc/mounts Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
2009-12-10kill wait_on_page_writeback_rangeChristoph Hellwig
All callers really want the more logical filemap_fdatawait_range interface, so convert them to use it and merge wait_on_page_writeback_range into filemap_fdatawait_range. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2009-12-10trivial: some small fixes in exofs documentationThadeu Lima de Souza Cascardo
Add exofs.txt to filesystems Documentation index and fix some typos, identation and grammar. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-09Doc: better explanation of procs_runningLuis Garces-Erice
the description in Documentation/filesystems/proc.txt of the procs_running entry in /proc/stat is confusing (according to that description, it looks as if procs_running could only be a number between 0 and the number of CPUs). Changed it to a more accurate description in the patch attached. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-05Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (35 commits) sched, cputime: Introduce thread_group_times() sched, cputime: Cleanups related to task_times() Revert "sched, x86: Optimize branch hint in __switch_to()" sched: Fix isolcpus boot option sched: Revert 498657a478c60be092208422fefa9c7b248729c2 sched, time: Define nsecs_to_jiffies() sched: Remove task_{u,s,g}time() sched: Introduce task_times() to replace task_{u,s}time() pair sched: Limit the number of scheduler debug messages sched.c: Call debug_show_all_locks() when dumping all tasks sched, x86: Optimize branch hint in __switch_to() sched: Optimize branch hint in context_switch() sched: Optimize branch hint in pick_next_task_fair() sched_feat_write(): Update ppos instead of file->f_pos sched: Sched_rt_periodic_timer vs cpu hotplug sched, kvm: Fix race condition involving sched_in_preempt_notifers sched: More generic WAKE_AFFINE vs select_idle_sibling() sched: Cleanup select_task_rq_fair() sched: Fix granularity of task_u/stime() sched: Fix/add missing update_rq_clock() calls ...
2009-11-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscacheLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscache: (31 commits) FS-Cache: Provide nop fscache_stat_d() if CONFIG_FSCACHE_STATS=n SLOW_WORK: Fix GFS2 to #include <linux/module.h> before using THIS_MODULE SLOW_WORK: Fix CIFS to pass THIS_MODULE to slow_work_register_user() CacheFiles: Don't log lookup/create failing with ENOBUFS CacheFiles: Catch an overly long wait for an old active object CacheFiles: Better showing of debugging information in active object problems CacheFiles: Mark parent directory locks as I_MUTEX_PARENT to keep lockdep happy CacheFiles: Handle truncate unlocking the page we're reading CacheFiles: Don't write a full page if there's only a partial page to cache FS-Cache: Actually requeue an object when requested FS-Cache: Start processing an object's operations on that object's death FS-Cache: Make sure FSCACHE_COOKIE_LOOKING_UP cleared on lookup failure FS-Cache: Add a retirement stat counter FS-Cache: Handle pages pending storage that get evicted under OOM conditions FS-Cache: Handle read request vs lookup, creation or other cache failure FS-Cache: Don't delete pending pages from the page-store tracking tree FS-Cache: Fix lock misorder in fscache_write_op() FS-Cache: The object-available state can't rely on the cookie to be available FS-Cache: Permit cache retrieval ops to be interrupted in the initial wait phase FS-Cache: Use radix tree preload correctly in tracking of pages to be stored ...
2009-11-26Merge branch 'sched/urgent' into sched/coreIngo Molnar
Merge reason: Pick up fixes that did not make it into .32.0 Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-23Merge commit 'v2.6.32-rc8' into HEADJ. Bruce Fields
2009-11-19Merge branch 'upstream-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2 * 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: ocfs2: Trivial cleanup of jbd compatibility layer removal ocfs2: Refresh documentation ocfs2: return f_fsid info in ocfs2_statfs() ocfs2: duplicate inline data properly during reflink. ocfs2: Move ocfs2_complete_reflink to the right place. ocfs2: Return -EINVAL when a device is not ocfs2.
2009-11-20nilfs2: add norecovery mount optionRyusuke Konishi
This adds "norecovery" mount option which disables temporal write access to read-only mounts or snapshots during mount/recovery. Without this option, write access will be even performed for those types of mounts; the temporal write access is needed to mount root file system read-only after an unclean shutdown. This option will be helpful when user wants to prevent any write access to the device. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Eric Sandeen <sandeen@redhat.com>
2009-11-20nilfs2: Using nobarrier option instead of barrier=offJiro SEKIBA
Since most of fs using nofoobar style option, modified barrier=off option as nobarrier. Signed-off-by: Jiro SEKIBA <jir@unicus.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
2009-11-19ext4: make "norecovery" an alias for "noload"Eric Sandeen
Users on the linux-ext4 list recently complained about differences across filesystems w.r.t. how to mount without a journal replay. In the discussion it was noted that xfs's "norecovery" option is perhaps more descriptively accurate than "noload," so let's make that an alias for ext4. Also show this status in /proc/mounts Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-11-19ext4: make trim/discard optional (and off by default)Eric Sandeen
It is anticipated that when sb_issue_discard starts doing real work on trim-capable devices, we may see issues. Make this mount-time optional, and default it to off until we know that things are working out OK. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-11-19CacheFiles: Catch an overly long wait for an old active objectDavid Howells
Catch an overly long wait for an old, dying active object when we want to replace it with a new one. The probability is that all the slow-work threads are hogged, and the delete can't get a look in. What we do instead is: (1) if there's nothing in the slow work queue, we sleep until either the dying object has finished dying or there is something in the slow work queue behind which we can queue our object. (2) if there is something in the slow work queue, we return ETIMEDOUT to fscache_lookup_object(), which then puts us back on the slow work queue, presumably behind the deletion that we're blocked by. We are then deferred for a while until we work our way back through the queue - without blocking a slow-work thread unnecessarily. A backtrace similar to the following may appear in the log without this patch: INFO: task kslowd004:5711 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kslowd004 D 0000000000000000 0 5711 2 0x00000080 ffff88000340bb80 0000000000000046 ffff88002550d000 0000000000000000 ffff88002550d000 0000000000000007 ffff88000340bfd8 ffff88002550d2a8 000000000000ddf0 00000000000118c0 00000000000118c0 ffff88002550d2a8 Call Trace: [<ffffffff81058e21>] ? trace_hardirqs_on+0xd/0xf [<ffffffffa011c4d8>] ? cachefiles_wait_bit+0x0/0xd [cachefiles] [<ffffffffa011c4e1>] cachefiles_wait_bit+0x9/0xd [cachefiles] [<ffffffff81353153>] __wait_on_bit+0x43/0x76 [<ffffffff8111ae39>] ? ext3_xattr_get+0x1ec/0x270 [<ffffffff813531ef>] out_of_line_wait_on_bit+0x69/0x74 [<ffffffffa011c4d8>] ? cachefiles_wait_bit+0x0/0xd [cachefiles] [<ffffffff8104c125>] ? wake_bit_function+0x0/0x2e [<ffffffffa011bc79>] cachefiles_mark_object_active+0x203/0x23b [cachefiles] [<ffffffffa011c209>] cachefiles_walk_to_object+0x558/0x827 [cachefiles] [<ffffffffa011a429>] cachefiles_lookup_object+0xac/0x12a [cachefiles] [<ffffffffa00aa1e9>] fscache_lookup_object+0x1c7/0x214 [fscache] [<ffffffffa00aafc5>] fscache_object_state_machine+0xa5/0x52d [fscache] [<ffffffffa00ab4ac>] fscache_object_slow_work_execute+0x5f/0xa0 [fscache] [<ffffffff81082093>] slow_work_execute+0x18f/0x2d1 [<ffffffff8108239a>] slow_work_thread+0x1c5/0x308 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810821d5>] ? slow_work_thread+0x0/0x308 [<ffffffff8104be91>] kthread+0x7a/0x82 [<ffffffff8100beda>] child_rip+0xa/0x20 [<ffffffff8100b87c>] ? restore_args+0x0/0x30 [<ffffffff8104be17>] ? kthread+0x0/0x82 [<ffffffff8100bed0>] ? child_rip+0x0/0x20 1 lock held by kslowd004/5711: #0: (&sb->s_type->i_mutex_key#7/1){+.+.+.}, at: [<ffffffffa011be64>] cachefiles_walk_to_object+0x1b3/0x827 [cachefiles] Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19FS-Cache: Start processing an object's operations on that object's deathDavid Howells
Start processing an object's operations when that object moves into the DYING state as the object cannot be destroyed until all its outstanding operations have completed. Furthermore, make sure that read and allocation operations handle being woken up on a dead object. Such events are recorded in the Allocs.abt and Retrvls.abt statistics as viewable through /proc/fs/fscache/stats. The code for waiting for object activation for the read and allocation operations is also extracted into its own function as it is much the same in all cases, differing only in the stats incremented. Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19FS-Cache: Handle pages pending storage that get evicted under OOM conditionsDavid Howells
Handle netfs pages that the vmscan algorithm wants to evict from the pagecache under OOM conditions, but that are waiting for write to the cache. Under these conditions, vmscan calls the releasepage() function of the netfs, asking if a page can be discarded. The problem is typified by the following trace of a stuck process: kslowd005 D 0000000000000000 0 4253 2 0x00000080 ffff88001b14f370 0000000000000046 ffff880020d0d000 0000000000000007 0000000000000006 0000000000000001 ffff88001b14ffd8 ffff880020d0d2a8 000000000000ddf0 00000000000118c0 00000000000118c0 ffff880020d0d2a8 Call Trace: [<ffffffffa00782d8>] __fscache_wait_on_page_write+0x8b/0xa7 [fscache] [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffffa0078240>] ? __fscache_check_page_write+0x63/0x70 [fscache] [<ffffffffa00b671d>] nfs_fscache_release_page+0x4e/0xc4 [nfs] [<ffffffffa00927f0>] nfs_release_page+0x3c/0x41 [nfs] [<ffffffff810885d3>] try_to_release_page+0x32/0x3b [<ffffffff81093203>] shrink_page_list+0x316/0x4ac [<ffffffff8109372b>] shrink_inactive_list+0x392/0x67c [<ffffffff813532fa>] ? __mutex_unlock_slowpath+0x100/0x10b [<ffffffff81058df0>] ? trace_hardirqs_on_caller+0x10c/0x130 [<ffffffff8135330e>] ? mutex_unlock+0x9/0xb [<ffffffff81093aa2>] shrink_list+0x8d/0x8f [<ffffffff81093d1c>] shrink_zone+0x278/0x33c [<ffffffff81052d6c>] ? ktime_get_ts+0xad/0xba [<ffffffff81094b13>] try_to_free_pages+0x22e/0x392 [<ffffffff81091e24>] ? isolate_pages_global+0x0/0x212 [<ffffffff8108e743>] __alloc_pages_nodemask+0x3dc/0x5cf [<ffffffff81089529>] grab_cache_page_write_begin+0x65/0xaa [<ffffffff8110f8c0>] ext3_write_begin+0x78/0x1eb [<ffffffff81089ec5>] generic_file_buffered_write+0x109/0x28c [<ffffffff8103cb69>] ? current_fs_time+0x22/0x29 [<ffffffff8108a509>] __generic_file_aio_write+0x350/0x385 [<ffffffff8108a588>] ? generic_file_aio_write+0x4a/0xae [<ffffffff8108a59e>] generic_file_aio_write+0x60/0xae [<ffffffff810b2e82>] do_sync_write+0xe3/0x120 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810b18e1>] ? __dentry_open+0x1a5/0x2b8 [<ffffffff810b1a76>] ? dentry_open+0x82/0x89 [<ffffffffa00e693c>] cachefiles_write_page+0x298/0x335 [cachefiles] [<ffffffffa0077147>] fscache_write_op+0x178/0x2c2 [fscache] [<ffffffffa0075656>] fscache_op_execute+0x7a/0xd1 [fscache] [<ffffffff81082093>] slow_work_execute+0x18f/0x2d1 [<ffffffff8108239a>] slow_work_thread+0x1c5/0x308 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810821d5>] ? slow_work_thread+0x0/0x308 [<ffffffff8104be91>] kthread+0x7a/0x82 [<ffffffff8100beda>] child_rip+0xa/0x20 [<ffffffff8100b87c>] ? restore_args+0x0/0x30 [<ffffffff8102ef83>] ? tg_shares_up+0x171/0x227 [<ffffffff8104be17>] ? kthread+0x0/0x82 [<ffffffff8100bed0>] ? child_rip+0x0/0x20 In the above backtrace, the following is happening: (1) A page storage operation is being executed by a slow-work thread (fscache_write_op()). (2) FS-Cache farms the operation out to the cache to perform (cachefiles_write_page()). (3) CacheFiles is then calling Ext3 to perform the actual write, using Ext3's standard write (do_sync_write()) under KERNEL_DS directly from the netfs page. (4) However, for Ext3 to perform the write, it must allocate some memory, in particular, it must allocate at least one page cache page into which it can copy the data from the netfs page. (5) Under OOM conditions, the memory allocator can't immediately come up with a page, so it uses vmscan to find something to discard (try_to_free_pages()). (6) vmscan finds a clean netfs page it might be able to discard (possibly the one it's trying to write out). (7) The netfs is called to throw the page away (nfs_release_page()) - but it's called with __GFP_WAIT, so the netfs decides to wait for the store to complete (__fscache_wait_on_page_write()). (8) This blocks a slow-work processing thread - possibly against itself. The system ends up stuck because it can't write out any netfs pages to the cache without allocating more memory. To avoid this, we make FS-Cache cancel some writes that aren't in the middle of actually being performed. This means that some data won't make it into the cache this time. To support this, a new FS-Cache function is added fscache_maybe_release_page() that replaces what the netfs releasepage() functions used to do with respect to the cache. The decisions fscache_maybe_release_page() makes are counted and displayed through /proc/fs/fscache/stats on a line labelled "VmScan". There are four counters provided: "nos=N" - pages that weren't pending storage; "gon=N" - pages that were pending storage when we first looked, but weren't by the time we got the object lock; "bsy=N" - pages that we ignored as they were actively being written when we looked; and "can=N" - pages that we cancelled the storage of. What I'd really like to do is alter the behaviour of the cancellation heuristics, depending on how necessary it is to expel pages. If there are plenty of other pages that aren't waiting to be written to the cache that could be ejected first, then it would be nice to hold up on immediate cancellation of cache writes - but I don't see a way of doing that. Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19FS-Cache: Handle read request vs lookup, creation or other cache failureDavid Howells
FS-Cache doesn't correctly handle the netfs requesting a read from the cache on an object that failed or was withdrawn by the cache. A trace similar to the following might be seen: CacheFiles: Lookup failed error -105 [exe ] unexpected submission OP165afe [OBJ6cac OBJECT_LC_DYING] [exe ] objstate=OBJECT_LC_DYING [OBJECT_LC_DYING] [exe ] objflags=0 [exe ] objevent=9 [fffffffffffffffb] [exe ] ops=0 inp=0 exc=0 Pid: 6970, comm: exe Not tainted 2.6.32-rc6-cachefs #50 Call Trace: [<ffffffffa0076477>] fscache_submit_op+0x3ff/0x45a [fscache] [<ffffffffa0077997>] __fscache_read_or_alloc_pages+0x187/0x3c4 [fscache] [<ffffffffa00b6480>] ? nfs_readpage_from_fscache_complete+0x0/0x66 [nfs] [<ffffffffa00b6388>] __nfs_readpages_from_fscache+0x7e/0x176 [nfs] [<ffffffff8108e483>] ? __alloc_pages_nodemask+0x11c/0x5cf [<ffffffffa009d796>] nfs_readpages+0x114/0x1d7 [nfs] [<ffffffff81090314>] __do_page_cache_readahead+0x15f/0x1ec [<ffffffff81090228>] ? __do_page_cache_readahead+0x73/0x1ec [<ffffffff810903bd>] ra_submit+0x1c/0x20 [<ffffffff810906bb>] ondemand_readahead+0x227/0x23a [<ffffffff81090762>] page_cache_sync_readahead+0x17/0x19 [<ffffffff8108a99e>] generic_file_aio_read+0x236/0x5a0 [<ffffffffa00937bd>] nfs_file_read+0xe4/0xf3 [nfs] [<ffffffff810b2fa2>] do_sync_read+0xe3/0x120 [<ffffffff81354cc3>] ? _spin_unlock_irq+0x2b/0x31 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff811848e5>] ? selinux_file_permission+0x5d/0x10f [<ffffffff81352bdb>] ? thread_return+0x3e/0x101 [<ffffffff8117d7b0>] ? security_file_permission+0x11/0x13 [<ffffffff810b3b06>] vfs_read+0xaa/0x16f [<ffffffff81058df0>] ? trace_hardirqs_on_caller+0x10c/0x130 [<ffffffff810b3c84>] sys_read+0x45/0x6c [<ffffffff8100ae2b>] system_call_fastpath+0x16/0x1b The object state might also be OBJECT_DYING or OBJECT_WITHDRAWING. This should be handled by simply rejecting the new operation with ENOBUFS. There's no need to log an error for it. Events of this type now appear in the stats file under Ops:rej. Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19FS-Cache: Fix lock misorder in fscache_write_op()David Howells
FS-Cache has two structs internally for keeping track of the internal state of a cached file: the fscache_cookie struct, which represents the netfs's state, and fscache_object struct, which represents the cache's state. Each has a pointer that points to the other (when both are in existence), and each has a spinlock for pointer maintenance. Since netfs operations approach these structures from the cookie side, they get the cookie lock first, then the object lock. Cache operations, on the other hand, approach from the object side, and get the object lock first. It is not then permitted for a cache operation to get the cookie lock whilst it is holding the object lock lest deadlock occur; instead, it must do one of two things: (1) increment the cookie usage counter, drop the object lock and then get both locks in order, or (2) simply hold the object lock as certain parts of the cookie may not be altered whilst the object lock is held. It is also not permitted to follow either pointer without holding the lock at the end you start with. To break the pointers between the cookie and the object, both locks must be held. fscache_write_op(), however, violates the locking rules: It attempts to get the cookie lock without (a) checking that the cookie pointer is a valid pointer, and (b) holding the object lock to protect the cookie pointer whilst it follows it. This is so that it can access the pending page store tree without interference from __fscache_write_page(). This is fixed by splitting the cookie lock, such that the page store tracking tree is protected by its own lock, and checking that the cookie pointer is non-NULL before we attempt to follow it whilst holding the object lock. The new lock is subordinate to both the cookie lock and the object lock, and so should be taken after those. Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19FS-Cache: Permit cache retrieval ops to be interrupted in the initial wait phaseDavid Howells
Permit the operations to retrieve data from the cache or to allocate space in the cache for future writes to be interrupted whilst they're waiting for permission for the operation to proceed. Typically this wait occurs whilst the cache object is being looked up on disk in the background. If an interruption occurs, and the operation has not yet been given the go-ahead to run, the operation is dequeued and cancelled, and control returns to the read operation of the netfs routine with none of the requested pages having been read or in any way marked as known by the cache. This means that the initial wait is done interruptibly rather than uninterruptibly. In addition, extra stats values are made available to show the number of ops cancelled and the number of cache space allocations interrupted. Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19FS-Cache: Add counters for entry/exit to/from cache operation functionsDavid Howells
Count entries to and exits from cache operation table functions. Maintain these as a single counter that's added to or removed from as appropriate. Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19FS-Cache: Allow the current state of all objects to be dumpedDavid Howells
Allow the current state of all fscache objects to be dumped by doing: cat /proc/fs/fscache/objects By default, all objects and all fields will be shown. This can be restricted by adding a suitable key to one of the caller's keyrings (such as the session keyring): keyctl add user fscache:objlist "<restrictions>" @s The <restrictions> are: K Show hexdump of object key (don't show if not given) A Show hexdump of object aux data (don't show if not given) And paired restrictions: C Show objects that have a cookie c Show objects that don't have a cookie B Show objects that are busy b Show objects that aren't busy W Show objects that have pending writes w Show objects that don't have pending writes R Show objects that have outstanding reads r Show objects that don't have outstanding reads S Show objects that have slow work queued s Show objects that don't have slow work queued If neither side of a restriction pair is given, then both are implied. For example: keyctl add user fscache:objlist KB @s shows objects that are busy, and lists their object keys, but does not dump their auxiliary data. It also implies "CcWwRrSs", but as 'B' is given, 'b' is not implied. Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-13ocfs2: Refresh documentationSunil Mushran
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-11-06nfs: move more to Documentation/filesystems/nfsJ. Bruce Fields
Oops: I missed two files in the first commit that created this directory. Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-11-02Revert "ext4: Remove journal_checksum mount option and enable it by default"Linus Torvalds
This reverts commit d0646f7b636d067d715fab52a2ba9c6f0f46b0d7, as requested by Eric Sandeen. It can basically cause an ext4 filesystem to miss recovery (and thus get mounted with errors) if the journal checksum does not match. Quoth Eric: "My hand-wavy hunch about what is happening is that we're finding a bad checksum on the last partially-written transaction, which is not surprising, but if we have a wrapped log and we're doing the initial scan for head/tail, and we abort scanning on that bad checksum, then we are essentially running an unrecovered filesystem. But that's hand-wavy and I need to go look at the code. We lived without journal checksums on by default until now, and at this point they're doing more harm than good, so we should revert the default-changing commit until we can fix it and do some good power-fail testing with the fixes in place." See http://bugzilla.kernel.org/show_bug.cgi?id=14354 for all the gory details. Requested-by: Eric Sandeen <sandeen@redhat.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Alexey Fisher <bug-track@fisher-privat.net> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Mathias Burén <mathias.buren@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-27nfs: new subdir Documentation/filesystems/nfsJ. Bruce Fields
We're adding enough nfs documentation that it may as well have its own subdirectory. Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-10-27Merge commit 'v2.6.32-rc5' into for-2.6.33J. Bruce Fields
2009-10-25sched, cpuacct: Fix niced guest time accountingRyota Ozaki
CPU time of a guest is always accounted in 'user' time without concern for the nice value of its counterpart process although the guest is scheduled under the nice value. This patch fixes the defect and accounts cpu time of a niced guest in 'nice' time as same as a niced process. And also the patch adds 'guest_nice' to cpuacct. The value provides niced guest cpu time which is like 'nice' to 'user'. The original discussions can be found here: http://www.mail-archive.com/kvm@vger.kernel.org/msg23982.html http://www.mail-archive.com/kvm@vger.kernel.org/msg23860.html Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com> Acked-by: Avi Kivity <avi@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1256314810-7897-1-git-send-email-ozaki.ryota@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-13ext3: Update documentation about ext3 quota mount optionsJan Kara
Signed-off-by: Jan Kara <jack@suse.cz>
2009-09-30Merge 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: ext4: Fix time encoding with extra epoch bits ext4: Add a stub for mpage_da_data in the trace header jbd2: Use tracepoints for history file ext4: Use tracepoints for mb_history trace file ext4, jbd2: Drop unneeded printks at mount and unmount time ext4: Handle nested ext4_journal_start/stop calls without a journal ext4: Make sure ext4_dirty_inode() updates the inode in no journal mode ext4: Avoid updating the inode table bh twice in no journal mode ext4: EXT4_IOC_MOVE_EXT: Check for different original and donor inodes first ext4: async direct IO for holes and fallocate support ext4: Use end_io callback to avoid direct I/O fallback to buffered I/O ext4: Split uninitialized extents for direct I/O ext4: release reserved quota when block reservation for delalloc retry ext4: Adjust ext4_da_writepages() to write out larger contiguous chunks ext4: Fix hueristic which avoids group preallocation for closed files ext4: Use ext4_msg() for ext4_da_writepage() errors ext4: Update documentation about quota mount options
2009-09-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6: fat: Check s_dirt in fat_sync_fs() vfat: change the default from shortname=lower to shortname=mixed fat/nls: Fix handling of utf8 invalid char
2009-09-30ext4: Use tracepoints for mb_history trace fileTheodore Ts'o
The /proc/fs/ext4/<dev>/mb_history was maintained manually, and had a number of problems: it required a largish amount of memory to be allocated for each ext4 filesystem, and the s_mb_history_lock introduced a CPU contention problem. By ripping out the mb_history code and replacing it with ftrace tracepoints, and we get more functionality: timestamps, event filtering, the ability to correlate mballoc history with other ext4 tracepoints, etc. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-28nfsd41: use sv_max_mesg for forechannel max sizesAndy Adamson
ca_maxresponsesize and ca_maxrequest size include the RPC header. sv_max_mesg is sv_max_payolad plus a page for overhead and is used in svc_init_buffer to allocate server buffer space for both the request and reply. Note that this means we can service an RPC compound that requires ca_maxrequestsize (MAXWRITE) or ca_max_responsesize (MAXREAD) but that we do not support an RPC compound that requires both ca_maxrequestsize and ca_maxresponsesize. Signed-off-by: Andy Adamson <andros@netapp.com> [bfields@citi.umich.edu: more documentation updates] Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-09-28nfsd: fix Documentation typoJ. Bruce Fields
Caught by Benny, thanks! Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-09-29ext4: Update documentation about quota mount optionsJan Kara
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-24Merge branch 'hwpoison' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits) HWPOISON: Enable error_remove_page on btrfs HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs HWPOISON: Add madvise() based injector for hardware poisoned pages v4 HWPOISON: Enable error_remove_page for NFS HWPOISON: Enable .remove_error_page for migration aware file systems HWPOISON: The high level memory error handler in the VM v7 HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process HWPOISON: shmem: call set_page_dirty() with locked page HWPOISON: Define a new error_remove_page address space op for async truncation HWPOISON: Add invalidate_inode_page HWPOISON: Refactor truncate to allow direct truncating of page v2 HWPOISON: check and isolate corrupted free pages v2 HWPOISON: Handle hardware poisoned pages in try_to_unmap HWPOISON: Use bitmask/action code for try_to_unmap behaviour HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2 HWPOISON: Add poison check to page fault handling HWPOISON: Add basic support for poisoned pages in fault handler v3 HWPOISON: Add new SIGBUS error codes for hardware poison signals HWPOISON: Add support for poison swap entries v2 HWPOISON: Export some rmap vma locking to outside world ...
2009-09-24doc/filesystems: more mount cleanupsPeng Tao
Documentation/filesystems/sharedsubtree.txt needs updating because the mount command in util-linux package is well aware of shared subtree features now. The patch also fixes two typos in sharedsubtree.txt. Signed-off-by: Peng Tao <bergwolf@gmail.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24doc/filesystems: remove smount programRandy Dunlap
mount(8) handles shared subtrees just fine, so remove the smount program from Documentation/filesystems/sharedsubtree.txt. Fix annoying "Lets" -> "Let's". Insert space between '#' prompt and "mount" command. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Miklos Szeredi <miklos@szeredi.hu> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-239p: Update documentation to add fscache related bitsAbhishek Kulkarni
Update the documentation to describe FS-Cache related caching parameters. This patch also updates the pointers to 9p-related papers and adds pointer to the Wiki. Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>