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* VFS: Export dquot_send_warningSteven Whitehouse2009-12-03
| | | | | | | | | | | Sending a message to userspace in a generic format to warn of events (e.g. quota exceeded) in the quota subsystem is a generically useful feature. This patch makes some minor changes to the send_message function from dquot.c renaming it quota_send_message, moving it to quota.c and exporting it for use by filesystems which do not use the dquot code. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Add set_xquota supportSteven Whitehouse2009-12-03
| | | | | | | This patch adds the ability to set GFS2 quota limit and warning levels via the XFS quota API. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Add get_xquota supportSteven Whitehouse2009-12-03
| | | | | | | | | | This adds support for viewing the current GFS2 quota settings via the XFS quota API. The setting of quotas will be addressed in a later patch. Fields which are not supported here are left set to zero. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Reviewed-by: Bob Peterson <rpeterso@redhat.com>
* GFS2: Clean up gfs2_adjust_quota() and do_glock()Steven Whitehouse2009-12-03
| | | | | | | | | | | | | Both of these functions contained confusing and in one case duplicate code. This patch adds a new check in do_glock() so that we report -ENOENT if we are asked to sync a quota entry which doesn't exist. Due to the previous patch this is now reported correctly to userspace. Also there are a few new comments, and I hope that the code is easier to understand now. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Remove constant argument from qd_get()Steven Whitehouse2009-12-03
| | | | | | | This function was only ever called with the "create" argument set to true, so we can remove it. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Remove constant argument from qdsb_get()Steven Whitehouse2009-12-03
| | | | | | | The "create" argument to qdsb_get() was only ever set to true, so this patch removes that argument. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Add proper error reporting to quota sync via sysfsSteven Whitehouse2009-12-03
| | | | | | For some reason, the errors were not making it to userspace. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Add get_xstate quota functionSteven Whitehouse2009-12-03
| | | | | | | This allows querying of the quota state via the XFS quota API. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Remove obsolete code in quota.cSteven Whitehouse2009-12-03
| | | | | | | There is no point in testing for GLF_DEMOTE here, we might as well always release the glock at that point. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Hook gfs2_quota_sync into VFS via gfs2_quotactl_opsSteven Whitehouse2009-12-03
| | | | | | | | | | | The plan is to add further operations to the gfs2_quotactl_ops in future patches. The sync operation is easy, so we start with that one. We plan to use the XFS quota control functions because they more closely match the GFS2 ones. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Alter arguments of gfs2_quota/statfs_syncSteven Whitehouse2009-12-03
| | | | | | | | | These two functions are altered so that gfs2_quota_sync may in future be called directly from the VFS. The GFS2 superblock changes to a VFS super block and there is an addition of an int argument which is currently ignored. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* VFS: Use GFP_NOFS in posix_acl_from_xattr()Steven Whitehouse2009-12-03
| | | | | | | GFS2 needs to call this from under a glock, so we need GFP_NOFS and I suspect that other filesystems might require this too. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Add cached ACLs supportSteven Whitehouse2009-12-03
| | | | | | | | | | The other patches in this series have been building towards being able to support cached ACLs like other filesystems. The only real difference with GFS2 is that we have to invalidate the cache when we drop a glock, but that is dealt with in earlier patches. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Clean up ACLsSteven Whitehouse2009-12-03
| | | | | | | | | To prepare for support for caching of ACLs, this cleans up the GFS2 ACL support by pushing the xattr code back into xattr.c and changing the acl_get function into one which only returns ACLs so that we can drop the caching function into it shortly. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Use gfs2_set_mode() instead of munge_mode()Steven Whitehouse2009-12-03
| | | | | | | These two functions do the same thing, so lets only use one of them. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Use forget_all_cached_acls()Steven Whitehouse2009-12-03
| | | | | | Invalidate all the cached ACLs when we drop the glock. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* GFS2: Fix up system xattrsSteven Whitehouse2009-12-03
| | | | | | | | | | This code has been shamelessly stolen from XFS at the suggestion of Christoph Hellwig. I've not added support for cached ACLs so far... watch for that in a later patch, although this is designed in such a way that they should be easy to add. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Christoph Hellwig <hch@infradead.org>
* GFS2: Fix -o meta mounts for subsequent mounts (i.e. all but the first one)Steven Whitehouse2009-12-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | We have a long term plan to use the "-o meta" flag to GFS2 mounts to access the alternate root which is used to store metadata for a GFS2 filesystem. This will allow us to eventually remove support for the gfs2meta filesystem type (which is in any case just a "front end" to the gfs2 filesystem type with the meta/master root). Currently the "-o meta" option is only taken into account on the initial mount of the filesystem. Subsequent mounts of the same filesystem (i.e. on the same device) result in basically the same as bind mounting the root of the original mount. This patch changes that by using what is more or less a copy of get_sb_bdev() and extending it so that it will take into account the alternate root in all cases. The main difference is that we have to parse the mount options a bit earlier. We can then use them to select the appropriate root towards the end of the function. In addition this also fixes a bug where it was possible (but certainly not desirable) to set different ro/rw options for the meta root when mounted via the gfs2meta fs compared with the original mount. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Alexander Viro <aviro@redhat.com>
* GFS2: Fix potential race in glock codeSteven Whitehouse2009-12-03
| | | | | | | We need to be careful of the ordering between clearing the GLF_LOCK bit and scheduling the workqueue. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* CacheFiles: Update IMA counters when using dentry_openMarc Dionne2009-12-01
| | | | | | | | | | When IMA is active, using dentry_open without updating the IMA counters will result in free/open imbalance errors when fput is eventually called. Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 9p: fix build breakage introduced by FS-CacheDavid Howells2009-12-01
| | | | | | | | | | | | | | | | | | | | | While building 2.6.32-rc8-git2 for Fedora I noticed the following thinko in commit 201a15428bd54f83eccec8b7c64a04b8f9431204 ("FS-Cache: Handle pages pending storage that get evicted under OOM conditions"): fs/9p/cache.c: In function '__v9fs_fscache_release_page': fs/9p/cache.c:346: error: 'vnode' undeclared (first use in this function) fs/9p/cache.c:346: error: (Each undeclared identifier is reported only once fs/9p/cache.c:346: error: for each function it appears in.) make[2]: *** [fs/9p/cache.o] Error 1 Fix the 9P filesystem to correctly construct the argument to fscache_maybe_release_page(). Signed-off-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Xiaotian Feng <dfeng@redhat.com> [from identical patch] Signed-off-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> [from identical patch] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6Linus Torvalds2009-11-30
|\ | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: [CIFS] Fix sparse warning [CIFS] Duplicate data on appending to some Samba servers [CIFS] fix oops in cifs_lookup during net boot
| * [CIFS] Fix sparse warningSteve French2009-11-24
| | | | | | | | | | | | Also update CHANGES file Signed-off-by: Steve French <sfrench@us.ibm.com>
| * [CIFS] Duplicate data on appending to some Samba serversSteve French2009-11-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SMB writes are sent with a starting offset and length. When the server supports the newer SMB trans2 posix open (rather than using the SMB NTCreateX) a file can be opened with SMB_O_APPEND flag, and for that case Samba server assumes that the offset sent in SMBWriteX is unneeded since the write should go to the end of the file - which can cause problems if the write was cached (since the beginning part of a page could be written twice by the client mm). Jeff suggested that masking the flag on posix open on the client is easiest for the time being. Note that recent Samba server also had an unrelated problem with SMB NTCreateX and append (see samba bugzilla bug number 6898) which should not affect current Linux clients (unless cifs Unix Extensions are disabled). The cifs client did not send the O_APPEND flag on posix open before 2.6.29 so the fix is unneeded on early kernels. In the future, for the non-cached case (O_DIRECT, and forcedirectio mounts) it would be possible and useful to send O_APPEND on posix open (for Windows case: FILE_APPEND_DATA but not FILE_WRITE_DATA on SMB NTCreateX) but for cached writes although the vfs sets the offset to end of file it may fragment a write across pages - so we can't send O_APPEND on open (could result in sending part of a page twice). CC: Stable <stable@kernel.org> Reviewed-by: Shirish Pargaonkar <shirishp@us.ibm.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
| * [CIFS] fix oops in cifs_lookup during net bootSteve French2009-11-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes bugzilla.kernel.org bug number 14641 Lookup called during network boot (network root filesystem for diskless workstation) has case where nd is null in lookup. This patch fixes that in cifs_lookup. (Shirish noted that 2.6.30 and 2.6.31 stable need the same check) Signed-off-by: Shirish Pargaonkar <shirishp@us.ibm.com> Acked-by: Jeff Layton <jlayton@redhat.com> Tested-by: Vladimir Stavrinov <vs@inist.ru> CC: Stable <stable@kernel.org> Signed-off-by: Steve French <sfrench@us.ibm.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2009-11-30
|\ \ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: reject O_DIRECT flag also in fuse_create
| * | fuse: reject O_DIRECT flag also in fuse_createCsaba Henk2009-11-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment in fuse_open about O_DIRECT: "VFS checks this, but only _after_ ->open()" also holds for fuse_create, however, the same kind of check was missing there. As an impact of this bug, open(newfile, O_RDWR|O_CREAT|O_DIRECT) fails, but a stub newfile will remain if the fuse server handled the implied FUSE_CREATE request appropriately. Other impact: in the above situation ima_file_free() will complain to open/free imbalance if CONFIG_IMA is set. Signed-off-by: Csaba Henk <csaba@gluster.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Harshavardhana <harsha@gluster.com> Cc: stable@kernel.org
* | | jffs2: Fix memory corruption in jffs2_read_inode_range()David Woodhouse2009-11-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In 2.6.23 kernel, commit a32ea1e1f925399e0d81ca3f7394a44a6dafa12c ("Fix read/truncate race") fixed a race in the generic code, and as a side effect, now do_generic_file_read() can ask us to readpage() past the i_size. This seems to be correctly handled by the block routines (e.g. block_read_full_page() fills the page with zeroes in case if somebody is trying to read past the last inode's block). JFFS2 doesn't handle this; it assumes that it won't be asked to read pages which don't exist -- and thus that there will be at least _one_ valid 'frag' on the page it's being asked to read. It will fill any holes with the following memset: memset(buf, 0, min(end, frag->ofs + frag->size) - offset); When the 'closest smaller match' returned by jffs2_lookup_node_frag() is actually on a previous page and ends before 'offset', that results in: memset(buf, 0, <huge unsigned negative>); Hopefully, in most cases the corruption is fatal, and quickly causing random oopses, like this: root@10.0.0.4:~/ltp-fs-20090531# ./testcases/kernel/fs/ftest/ftest01 Unable to handle kernel paging request for data at address 0x00000008 Faulting instruction address: 0xc01cd980 Oops: Kernel access of bad area, sig: 11 [#1] [...] NIP [c01cd980] rb_insert_color+0x38/0x184 LR [c0043978] enqueue_hrtimer+0x88/0xc4 Call Trace: [c6c63b60] [c004f9a8] tick_sched_timer+0xa0/0xe4 (unreliable) [c6c63b80] [c0043978] enqueue_hrtimer+0x88/0xc4 [c6c63b90] [c0043a48] __run_hrtimer+0x94/0xbc [c6c63bb0] [c0044628] hrtimer_interrupt+0x140/0x2b8 [c6c63c10] [c000f8e8] timer_interrupt+0x13c/0x254 [c6c63c30] [c001352c] ret_from_except+0x0/0x14 --- Exception: 901 at memset+0x38/0x5c LR = jffs2_read_inode_range+0x144/0x17c [c6c63cf0] [00000000] (null) (unreliable) This patch fixes the issue, plus fixes all LTP tests on NAND/UBI with JFFS2 filesystem that were failing since 2.6.23 (seems like the bug above also broke the truncation). Reported-By: Anton Vorontsov <avorontsov@ru.mvista.com> Tested-By: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscacheLinus Torvalds2009-11-30
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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 ...
| * | FS-Cache: Provide nop fscache_stat_d() if CONFIG_FSCACHE_STATS=nDavid Howells2009-11-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide nop fscache_stat_d() macro if CONFIG_FSCACHE_STATS=n lest errors like the following occur: fs/fscache/cache.c: In function 'fscache_withdraw_cache': fs/fscache/cache.c:386: error: implicit declaration of function 'fscache_stat_d' fs/fscache/cache.c:386: error: 'fscache_n_cop_sync_cache' undeclared (first use in this function) fs/fscache/cache.c:386: error: (Each undeclared identifier is reported only once fs/fscache/cache.c:386: error: for each function it appears in.) fs/fscache/cache.c:392: error: 'fscache_n_cop_dissociate_pages' undeclared (first use in this function) Signed-off-by: David Howells <dhowells@redhat.com>
| * | SLOW_WORK: Fix GFS2 to #include <linux/module.h> before using THIS_MODULEDavid Howells2009-11-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GFS2 has been altered to pass THIS_MODULE to slow_work_register_user(), but hasn't been altered to #include <linux/module.h> to provide it, resulting in the following error: fs/gfs2/recovery.c:596: error: 'THIS_MODULE' undeclared here (not in a function) Add the missing #include. Signed-off-by: David Howells <dhowells@redhat.com>
| * | SLOW_WORK: Fix CIFS to pass THIS_MODULE to slow_work_register_user()David Howells2009-11-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of the patch: SLOW_WORK: Wait for outstanding work items belonging to a module to clear Wait for outstanding slow work items belonging to a module to clear when unregistering that module as a user of the facility. This prevents the put_ref code of a work item from being taken away before it returns. slow_work_register_user() takes a module pointer as an argument. CIFS must now pass THIS_MODULE as that argument, lest the following error be observed: fs/cifs/cifsfs.c: In function 'init_cifs': fs/cifs/cifsfs.c:1040: error: too few arguments to function 'slow_work_register_user' Signed-off-by: David Howells <dhowells@redhat.com>
| * | CacheFiles: Don't log lookup/create failing with ENOBUFSDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't log the CacheFiles lookup/create object routined failing with ENOBUFS as under high memory load or high cache load they can do this quite a lot. This error simply means that the requested object cannot be created on disk due to lack of space, or due to failure of the backing filesystem to find sufficient resources. Signed-off-by: David Howells <dhowells@redhat.com>
| * | CacheFiles: Catch an overly long wait for an old active objectDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | CacheFiles: Better showing of debugging information in active object problemsDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Show more debugging information if cachefiles_mark_object_active() is asked to activate an active object. This may happen, for instance, if the netfs tries to register an object with the same key multiple times. The code is changed to (a) get the appropriate object lock to protect the cookie pointer whilst we dereference it, and (b) get and display the cookie key if available. Signed-off-by: David Howells <dhowells@redhat.com>
| * | CacheFiles: Mark parent directory locks as I_MUTEX_PARENT to keep lockdep happyDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mark parent directory locks as I_MUTEX_PARENT in the callers of cachefiles_bury_object() so that lockdep doesn't complain when that invokes vfs_unlink(): ============================================= [ INFO: possible recursive locking detected ] 2.6.32-rc6-cachefs #47 --------------------------------------------- kslowd002/3089 is trying to acquire lock: (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffff810bbf72>] vfs_unlink+0x8b/0x128 but task is already holding lock: (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffffa00e4e61>] cachefiles_walk_to_object+0x1b0/0x831 [cachefiles] other info that might help us debug this: 1 lock held by kslowd002/3089: #0: (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffffa00e4e61>] cachefiles_walk_to_object+0x1b0/0x831 [cachefiles] stack backtrace: Pid: 3089, comm: kslowd002 Not tainted 2.6.32-rc6-cachefs #47 Call Trace: [<ffffffff8105ad7b>] __lock_acquire+0x1649/0x16e3 [<ffffffff8118170e>] ? inode_has_perm+0x5f/0x61 [<ffffffff8105ae6c>] lock_acquire+0x57/0x6d [<ffffffff810bbf72>] ? vfs_unlink+0x8b/0x128 [<ffffffff81353ac3>] mutex_lock_nested+0x54/0x292 [<ffffffff810bbf72>] ? vfs_unlink+0x8b/0x128 [<ffffffff8118179e>] ? selinux_inode_permission+0x8e/0x90 [<ffffffff8117e271>] ? security_inode_permission+0x1c/0x1e [<ffffffff810bb4fb>] ? inode_permission+0x99/0xa5 [<ffffffff810bbf72>] vfs_unlink+0x8b/0x128 [<ffffffff810adb19>] ? kfree+0xed/0xf9 [<ffffffffa00e3f00>] cachefiles_bury_object+0xb6/0x420 [cachefiles] [<ffffffff81058e21>] ? trace_hardirqs_on+0xd/0xf [<ffffffffa00e7e24>] ? cachefiles_check_object_xattr+0x233/0x293 [cachefiles] [<ffffffffa00e51b0>] cachefiles_walk_to_object+0x4ff/0x831 [cachefiles] [<ffffffff81032238>] ? finish_task_switch+0x0/0xb2 [<ffffffffa00e3429>] cachefiles_lookup_object+0xac/0x12a [cachefiles] [<ffffffffa00741e9>] fscache_lookup_object+0x1c7/0x214 [fscache] [<ffffffffa0074fc5>] fscache_object_state_machine+0xa5/0x52d [fscache] [<ffffffffa00754ac>] 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 Signed-off-by: Daivd Howells <dhowells@redhat.com>
| * | CacheFiles: Handle truncate unlocking the page we're readingDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handle truncate unlocking the page we're attempting to read from the backing device before the read has completed. This was causing reports like the following to occur: Pid: 4765, comm: kslowd Not tainted 2.6.30.1 #1 Call Trace: [<ffffffffa0331d7a>] ? cachefiles_read_waiter+0xd9/0x147 [cachefiles] [<ffffffff804b74bd>] ? __wait_on_bit+0x60/0x6f [<ffffffff8022bbbb>] ? __wake_up_common+0x3f/0x71 [<ffffffff8022cc32>] ? __wake_up+0x30/0x44 [<ffffffff8024a41f>] ? __wake_up_bit+0x28/0x2d [<ffffffffa003a793>] ? ext3_truncate+0x4d7/0x8ed [ext3] [<ffffffff80281f90>] ? pagevec_lookup+0x17/0x1f [<ffffffff8028c2ff>] ? unmap_mapping_range+0x59/0x1ff [<ffffffff8022cc32>] ? __wake_up+0x30/0x44 [<ffffffff8028e286>] ? vmtruncate+0xc2/0xe2 [<ffffffff802b82cf>] ? inode_setattr+0x22/0x10a [<ffffffffa003baa5>] ? ext3_setattr+0x17b/0x1e6 [ext3] [<ffffffff802b853d>] ? notify_change+0x186/0x2c9 [<ffffffffa032d9de>] ? cachefiles_attr_changed+0x133/0x1cd [cachefiles] [<ffffffffa032df7f>] ? cachefiles_lookup_object+0xcf/0x12a [cachefiles] [<ffffffffa0318165>] ? fscache_lookup_object+0x110/0x122 [fscache] [<ffffffffa03188c3>] ? fscache_object_slow_work_execute+0x590/0x6bc [fscache] [<ffffffff80278f82>] ? slow_work_thread+0x285/0x43a [<ffffffff8024a446>] ? autoremove_wake_function+0x0/0x2e [<ffffffff80278cfd>] ? slow_work_thread+0x0/0x43a [<ffffffff8024a317>] ? kthread+0x54/0x81 [<ffffffff8020c93a>] ? child_rip+0xa/0x20 [<ffffffff8024a2c3>] ? kthread+0x0/0x81 [<ffffffff8020c930>] ? child_rip+0x0/0x20 CacheFiles: I/O Error: Readpage failed on backing file 200000000000810 FS-Cache: Cache cachefiles stopped due to I/O error Reported-by: Christian Kujau <lists@nerdbynature.de> Reported-by: Takashi Iwai <tiwai@suse.de> Reported-by: Duc Le Minh <duclm.vn@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
| * | CacheFiles: Don't write a full page if there's only a partial page to cacheDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cachefiles_write_page() writes a full page to the backing file for the last page of the netfs file, even if the netfs file's last page is only a partial page. This causes the EOF on the backing file to be extended beyond the EOF of the netfs, and thus the backing file will be truncated by cachefiles_attr_changed() called from cachefiles_lookup_object(). So we need to limit the write we make to the backing file on that last page such that it doesn't push the EOF too far. Also, if a backing file that has a partial page at the end is expanded, we discard the partial page and refetch it on the basis that we then have a hole in the file with invalid data, and should the power go out... A better way to deal with this could be to record a note that the partial page contains invalid data until the correct data is written into it. This isn't a problem for netfs's that discard the whole backing file if the file size changes (such as NFS). Signed-off-by: David Howells <dhowells@redhat.com>
| * | FS-Cache: Actually requeue an object when requestedDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | FS-Cache objects have an FSCACHE_OBJECT_EV_REQUEUE event that can theoretically be raised to ask the state machine to requeue the object for further processing before the work function returns to the slow-work facility. However, fscache_object_work_execute() was clearing that bit before checking the event mask to see whether the object has any pending events that require it to be requeued immediately. Instead, the bit should be cleared after the check and enqueue. Signed-off-by: David Howells <dhowells@redhat.com>
| * | FS-Cache: Start processing an object's operations on that object's deathDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | FS-Cache: Make sure FSCACHE_COOKIE_LOOKING_UP cleared on lookup failureDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We must make sure that FSCACHE_COOKIE_LOOKING_UP is cleared on lookup failure (if an object reaches the LC_DYING state), and we should clear it before clearing FSCACHE_COOKIE_CREATING. If this doesn't happen then fscache_wait_for_deferred_lookup() may hold allocation and retrieval operations indefinitely until they're interrupted by signals - which in turn pins the dying object until they go away. Signed-off-by: David Howells <dhowells@redhat.com>
| * | FS-Cache: Add a retirement stat counterDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | Add a stat counter to count retirement events rather than ordinary release events (the retire argument to fscache_relinquish_cookie()). Signed-off-by: David Howells <dhowells@redhat.com>
| * | FS-Cache: Handle pages pending storage that get evicted under OOM conditionsDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | FS-Cache: Handle read request vs lookup, creation or other cache failureDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | FS-Cache: Don't delete pending pages from the page-store tracking treeDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | Don't delete pending pages from the page-store tracking tree, but rather send them for another write as they've presumably been updated. Signed-off-by: David Howells <dhowells@redhat.com>
| * | FS-Cache: Fix lock misorder in fscache_write_op()David Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | FS-Cache: The object-available state can't rely on the cookie to be availableDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The object-available state in the object processing state machine (as processed by fscache_object_available()) can't rely on the cookie to be available because the FSCACHE_COOKIE_CREATING bit may have been cleared by fscache_obtained_object() prior to the object being put into the FSCACHE_OBJECT_AVAILABLE state. Clearing the FSCACHE_COOKIE_CREATING bit on a cookie permits __fscache_relinquish_cookie() to proceed and detach the cookie from the object. To deal with this, we don't dereference object->cookie in fscache_object_available() if the object has already been detached. In addition, a couple of assertions are added into fscache_drop_object() to make sure the object is unbound from the cookie before it gets there. Signed-off-by: David Howells <dhowells@redhat.com>
| * | FS-Cache: Permit cache retrieval ops to be interrupted in the initial wait phaseDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | FS-Cache: Use radix tree preload correctly in tracking of pages to be storedDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __fscache_write_page() attempts to load the radix tree preallocation pool for the CPU it is on before calling radix_tree_insert(), as the insertion must be done inside a pair of spinlocks. Use of the preallocation pool, however, is contingent on the radix tree being initialised without __GFP_WAIT specified. __fscache_acquire_cookie() was passing GFP_NOFS to INIT_RADIX_TREE() - but that includes __GFP_WAIT. The solution is to AND out __GFP_WAIT. Additionally, the banner comment to radix_tree_preload() is altered to make note of this prerequisite. Possibly there should be a WARN_ON() too. Without this fix, I have seen the following recursive deadlock caused by radix_tree_insert() attempting to allocate memory inside the spinlocked region, which resulted in FS-Cache being called back into to release memory - which required the spinlock already held. ============================================= [ INFO: possible recursive locking detected ] 2.6.32-rc6-cachefs #24 --------------------------------------------- nfsiod/7916 is trying to acquire lock: (&cookie->lock){+.+.-.}, at: [<ffffffffa0076872>] __fscache_uncache_page+0xdb/0x160 [fscache] but task is already holding lock: (&cookie->lock){+.+.-.}, at: [<ffffffffa0076acc>] __fscache_write_page+0x15c/0x3f3 [fscache] other info that might help us debug this: 5 locks held by nfsiod/7916: #0: (nfsiod){+.+.+.}, at: [<ffffffff81048290>] worker_thread+0x19a/0x2e2 #1: (&task->u.tk_work#2){+.+.+.}, at: [<ffffffff81048290>] worker_thread+0x19a/0x2e2 #2: (&cookie->lock){+.+.-.}, at: [<ffffffffa0076acc>] __fscache_write_page+0x15c/0x3f3 [fscache] #3: (&object->lock#2){+.+.-.}, at: [<ffffffffa0076b07>] __fscache_write_page+0x197/0x3f3 [fscache] #4: (&cookie->stores_lock){+.+...}, at: [<ffffffffa0076b0f>] __fscache_write_page+0x19f/0x3f3 [fscache] stack backtrace: Pid: 7916, comm: nfsiod Not tainted 2.6.32-rc6-cachefs #24 Call Trace: [<ffffffff8105ac7f>] __lock_acquire+0x1649/0x16e3 [<ffffffff81059ded>] ? __lock_acquire+0x7b7/0x16e3 [<ffffffff8100e27d>] ? dump_trace+0x248/0x257 [<ffffffff8105ad70>] lock_acquire+0x57/0x6d [<ffffffffa0076872>] ? __fscache_uncache_page+0xdb/0x160 [fscache] [<ffffffff8135467c>] _spin_lock+0x2c/0x3b [<ffffffffa0076872>] ? __fscache_uncache_page+0xdb/0x160 [fscache] [<ffffffffa0076872>] __fscache_uncache_page+0xdb/0x160 [fscache] [<ffffffffa0077eb7>] ? __fscache_check_page_write+0x0/0x71 [fscache] [<ffffffffa00b4755>] nfs_fscache_release_page+0x86/0xc4 [nfs] [<ffffffffa00907f0>] nfs_release_page+0x3c/0x41 [nfs] [<ffffffff81087ffb>] try_to_release_page+0x32/0x3b [<ffffffff81092c2b>] shrink_page_list+0x316/0x4ac [<ffffffff81058a9b>] ? mark_held_locks+0x52/0x70 [<ffffffff8135451b>] ? _spin_unlock_irq+0x2b/0x31 [<ffffffff81093153>] shrink_inactive_list+0x392/0x67c [<ffffffff81058a9b>] ? mark_held_locks+0x52/0x70 [<ffffffff810934ca>] shrink_list+0x8d/0x8f [<ffffffff81093744>] shrink_zone+0x278/0x33c [<ffffffff81052c70>] ? ktime_get_ts+0xad/0xba [<ffffffff8109453b>] try_to_free_pages+0x22e/0x392 [<ffffffff8109184c>] ? isolate_pages_global+0x0/0x212 [<ffffffff8108e16b>] __alloc_pages_nodemask+0x3dc/0x5cf [<ffffffff810ae24a>] cache_alloc_refill+0x34d/0x6c1 [<ffffffff811bcf74>] ? radix_tree_node_alloc+0x52/0x5c [<ffffffff810ae929>] kmem_cache_alloc+0xb2/0x118 [<ffffffff811bcf74>] radix_tree_node_alloc+0x52/0x5c [<ffffffff811bcfd5>] radix_tree_insert+0x57/0x19c [<ffffffffa0076b53>] __fscache_write_page+0x1e3/0x3f3 [fscache] [<ffffffffa00b4248>] __nfs_readpage_to_fscache+0x58/0x11e [nfs] [<ffffffffa009bb77>] nfs_readpage_release+0x34/0x9b [nfs] [<ffffffffa009c0d9>] nfs_readpage_release_full+0x32/0x4b [nfs] [<ffffffffa0006cff>] rpc_release_calldata+0x12/0x14 [sunrpc] [<ffffffffa0006e2d>] rpc_free_task+0x59/0x61 [sunrpc] [<ffffffffa0006f03>] rpc_async_release+0x10/0x12 [sunrpc] [<ffffffff810482e5>] worker_thread+0x1ef/0x2e2 [<ffffffff81048290>] ? worker_thread+0x19a/0x2e2 [<ffffffff81352433>] ? thread_return+0x3e/0x101 [<ffffffffa0006ef3>] ? rpc_async_release+0x0/0x12 [sunrpc] [<ffffffff8104bff5>] ? autoremove_wake_function+0x0/0x34 [<ffffffff81058d25>] ? trace_hardirqs_on+0xd/0xf [<ffffffff810480f6>] ? worker_thread+0x0/0x2e2 [<ffffffff8104bd21>] kthread+0x7a/0x82 [<ffffffff8100beda>] child_rip+0xa/0x20 [<ffffffff8100b87c>] ? restore_args+0x0/0x30 [<ffffffff8104c2b9>] ? add_wait_queue+0x15/0x44 [<ffffffff8104bca7>] ? kthread+0x0/0x82 [<ffffffff8100bed0>] ? child_rip+0x0/0x20 Signed-off-by: David Howells <dhowells@redhat.com>
| * | FS-Cache: Clear netfs pointers in cookie after detaching object, not beforeDavid Howells2009-11-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clear the pointers from the fscache_cookie struct to netfs private data after clearing the pointer to the cookie from the fscache_object struct and releasing the object lock, rather than before. This allows the netfs private data pointers to be relied on simply by holding the object lock, rather than having to hold the cookie lock. This is makes things simpler as the cookie lock has to be taken before the object lock, but sometimes the object pointer is all that the code has. Signed-off-by: David Howells <dhowells@redhat.com>