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2012-11-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-26Merge branch 'akpm' (Fixes from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "8 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (8 patches) futex: avoid wake_futex() for a PI futex_q watchdog: using u64 in get_sample_period() writeback: put unused inodes to LRU after writeback completion mm: vmscan: check for fatal signals iff the process was throttled Revert "mm: remove __GFP_NO_KSWAPD" proc: check vma->vm_file before dereferencing UAPI: strip the _UAPI prefix from header guards during header installation include/linux/bug.h: fix sparse warning related to BUILD_BUG_ON_INVALID
2012-11-26Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull ext3 regression fix from Jan Kara: "Fix an ext3 regression introduced during 3.7 merge window. It leads to deadlock if you stress the filesystem in the right way (luckily only if blocksize < pagesize)." * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: jbd: Fix lock ordering bug in journal_unmap_buffer()
2012-11-26writeback: put unused inodes to LRU after writeback completionJan Kara
Commit 169ebd90131b ("writeback: Avoid iput() from flusher thread") removed iget-iput pair from inode writeback. As a side effect, inodes that are dirty during iput_final() call won't be ever added to inode LRU (iput_final() doesn't add dirty inodes to LRU and later when the inode is cleaned there's noone to add the inode there). Thus inodes are effectively unreclaimable until someone looks them up again. The practical effect of this bug is limited by the fact that inodes are pinned by a dentry for long enough that the inode gets cleaned. But still the bug can have nasty consequences leading up to OOM conditions under certain circumstances. Following can easily reproduce the problem: for (( i = 0; i < 1000; i++ )); do mkdir $i for (( j = 0; j < 1000; j++ )); do touch $i/$j echo 2 > /proc/sys/vm/drop_caches done done then one needs to run 'sync; ls -lR' to make inodes reclaimable again. We fix the issue by inserting unused clean inodes into the LRU after writeback finishes in inode_sync_complete(). Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: <stable@vger.kernel.org> [3.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-26proc: check vma->vm_file before dereferencingStanislav Kinsbursky
Commit 7b540d0646ce ("proc_map_files_readdir(): don't bother with grabbing files") switched proc_map_files_readdir() to use @f_mode directly instead of grabbing @file reference, but same time the test for @vm_file presence was lost leading to nil dereference. The patch brings the test back. The all proc_map_files feature is CONFIG_CHECKPOINT_RESTORE wrapped (which is set to 'n' by default) so the bug doesn't affect regular kernels. The regression is 3.7-rc1 only as far as I can tell. [gorcunov@openvz.org: provided changelog] Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/wireless/iwlwifi/pcie/tx.c Minor iwlwifi conflict in TX queue disabling between 'net', which removed a bogus warning, and 'net-next' which added some status register poking code. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-23Merge tag 'for-linus-20121123' of git://git.infradead.org/mtd-2.6Linus Torvalds
Pull MTD fixes from David Woodhouse: "The most important part of this is that it fixes a regression in Samsung NAND chip detection, introduced by some rework which went into 3.7. The initial fix wasn't quite complete, so it's in two parts. In fact the first part is committed twice (Artem committed his own copy of the same patch) and I've merged Artem's tree into mine which already had that fix. I'd have recommitted that to make it somewhat cleaner, but figured by this point in the release cycle it was better to merge *exactly* the commits which have been in linux-next. If I'd recommitted, I'd also omit the sparse warning fix. But it's there, and it's harmless — just marking one function as 'static' in onenand code. This also includes a couple more fixes for stable: an AB-BA deadlock in JFFS2, and an invalid range check in slram." * tag 'for-linus-20121123' of git://git.infradead.org/mtd-2.6: mtd: nand: fix Samsung SLC detection regression mtd: nand: fix Samsung SLC NAND identification regression jffs2: Fix lock acquisition order bug in jffs2_write_begin mtd: onenand: Make flexonenand_set_boundary static mtd: slram: invalid checking of absolute end address mtd: ofpart: Fix incorrect NULL check in parse_ofoldpart_partitions() mtd: nand: fix Samsung SLC NAND identification regression
2012-11-23jbd: Fix lock ordering bug in journal_unmap_buffer()Jan Kara
Commit 09e05d48 introduced a wait for transaction commit into journal_unmap_buffer() in the case we are truncating a buffer undergoing commit in the page stradding i_size on a filesystem with blocksize < pagesize. Sadly we forgot to drop buffer lock before waiting for transaction commit and thus deadlock is possible when kjournald wants to lock the buffer. Fix the problem by dropping the buffer lock before waiting for transaction commit. Since we are still holding page lock (and that is OK), buffer cannot disappear under us. CC: stable@vger.kernel.org # Wherever commit 09e05d48 was taken Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-20Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull reiserfs and ext3 fixes from Jan Kara: "Fixes of reiserfs deadlocks when quotas are enabled (locking there was completely busted by BKL conversion) and also one small ext3 fix in the trim interface." * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: ext3: Avoid underflow of in ext3_trim_fs() reiserfs: Move quota calls out of write lock reiserfs: Protect reiserfs_quota_write() with write lock reiserfs: Protect reiserfs_quota_on() with write lock reiserfs: Fix lock ordering during remount
2012-11-19ext3: Avoid underflow of in ext3_trim_fs()Lukas Czerner
Currently if len argument in ext3_trim_fs() is smaller than one block, the 'end' variable underflow. Avoid that by returning EINVAL if len is smaller than file system block. Also remove useless unlikely(). Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-19reiserfs: Move quota calls out of write lockJan Kara
Calls into highlevel quota code cannot happen under the write lock. These calls take dqio_mutex which ranks above write lock. So drop write lock before calling back into quota code. CC: stable@vger.kernel.org # >= 3.0 Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-19reiserfs: Protect reiserfs_quota_write() with write lockJan Kara
Calls into reiserfs journalling code and reiserfs_get_block() need to be protected with write lock. We remove write lock around calls to high level quota code in the next patch so these paths would suddently become unprotected. CC: stable@vger.kernel.org # >= 3.0 Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-19reiserfs: Protect reiserfs_quota_on() with write lockJan Kara
In reiserfs_quota_on() we do quite some work - for example unpacking tail of a quota file. Thus we have to hold write lock until a moment we call back into the quota code. CC: stable@vger.kernel.org # >= 3.0 Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-19reiserfs: Fix lock ordering during remountJan Kara
When remounting reiserfs dquot_suspend() or dquot_resume() can be called. These functions take dqonoff_mutex which ranks above write lock so we have to drop it before calling into quota code. CC: stable@vger.kernel.org # >= 3.0 Signed-off-by: Jan Kara <jack@suse.cz>
2012-11-18sysctl: Pass useful parameters to sysctl permissionsEric W. Biederman
- Current is implicitly avaiable so passing current->nsproxy isn't useful. - The ctl_table_header is needed to find how the sysctl table is connected to the rest of sysctl. - ctl_table_root is avaiable in the ctl_table_header so no need to it. With these changes it becomes possible to write a version of net_sysctl_permission that takes into account the network namespace of the sysctl table, an important feature in extending the user namespace. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-18fanotify: fix FAN_Q_OVERFLOW case of fanotify_read()Al Viro
If the FAN_Q_OVERFLOW bit set in event->mask, the fanotify event metadata will not contain a valid file descriptor, but copy_event_to_user() didn't check for that, and unconditionally does a fd_install() on the file descriptor. Which in turn will cause a BUG_ON() in __fd_install(). Introduced by commit 352e3b249284 ("fanotify: sanitize failure exits in copy_event_to_user()") Mea culpa - missed that path ;-/ Reported-by: Alex Shi <lkml.alex@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-18Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc VFS fixes from Al Viro: "Remove a bogus BUG_ON() that can trigger spuriously + alpha bits of do_mount() constification I'd missed during the merge window." This pull request came in a week ago, I missed it for some reason. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: kill bogus BUG_ON() in do_close_on_exec() missing const in alpha callers of do_mount()
2012-11-18Merge tag 'for-linus-v3.7-rc7' of git://oss.sgi.com/xfs/xfsLinus Torvalds
Pull xfs bugfixes from Ben Myers: - fix attr tree double split corruption - fix broken error handling in xfs_vm_writepage - drop buffer io reference when a bad bio is built * tag 'for-linus-v3.7-rc7' of git://oss.sgi.com/xfs/xfs: xfs: drop buffer io reference when a bad bio is built xfs: fix broken error handling in xfs_vm_writepage xfs: fix attr tree double split corruption
2012-11-17xfs: drop buffer io reference when a bad bio is builtDave Chinner
Error handling in xfs_buf_ioapply_map() does not handle IO reference counts correctly. We increment the b_io_remaining count before building the bio, but then fail to decrement it in the failure case. This leads to the buffer never running IO completion and releasing the reference that the IO holds, so at unmount we can leak the buffer. This leak is captured by this assert failure during unmount: XFS: Assertion failed: atomic_read(&pag->pag_ref) == 0, file: fs/xfs/xfs_mount.c, line: 273 This is not a new bug - the b_io_remaining accounting has had this problem for a long, long time - it's just very hard to get a zero length bio being built by this code... Further, the buffer IO error can be overwritten on a multi-segment buffer by subsequent bio completions for partial sections of the buffer. Hence we should only set the buffer error status if the buffer is not already carrying an error status. This ensures that a partial IO error on a multi-segment buffer will not be lost. This part of the problem is a regression, however. cc: <stable@vger.kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-17xfs: fix broken error handling in xfs_vm_writepageDave Chinner
When we shut down the filesystem, it might first be detected in writeback when we are allocating a inode size transaction. This happens after we have moved all the pages into the writeback state and unlocked them. Unfortunately, if we fail to set up the transaction we then abort writeback and try to invalidate the current page. This then triggers are BUG() in block_invalidatepage() because we are trying to invalidate an unlocked page. Fixing this is a bit of a chicken and egg problem - we can't allocate the transaction until we've clustered all the pages into the IO and we know the size of it (i.e. whether the last block of the IO is beyond the current EOF or not). However, we don't want to hold pages locked for long periods of time, especially while we lock other pages to cluster them into the write. To fix this, we need to make a clear delineation in writeback where errors can only be handled by IO completion processing. That is, once we have marked a page for writeback and unlocked it, we have to report errors via IO completion because we've already started the IO. We may not have submitted any IO, but we've changed the page state to indicate that it is under IO so we must now use the IO completion path to report errors. To do this, add an error field to xfs_submit_ioend() to pass it the error that occurred during the building on the ioend chain. When this is non-zero, mark each ioend with the error and call xfs_finish_ioend() directly rather than building bios. This will immediately push the ioends through completion processing with the error that has occurred. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-17xfs: fix attr tree double split corruptionDave Chinner
In certain circumstances, a double split of an attribute tree is needed to insert or replace an attribute. In rare situations, this can go wrong, leaving the attribute tree corrupted. In this case, the attr being replaced is the last attr in a leaf node, and the replacement is larger so doesn't fit in the same leaf node. When we have the initial condition of a node format attribute btree with two leaves at index 1 and 2. Call them L1 and L2. The leaf L1 is completely full, there is not a single byte of free space in it. L2 is mostly empty. The attribute being replaced - call it X - is the last attribute in L1. The way an attribute replace is executed is that the replacement attribute - call it Y - is first inserted into the tree, but has an INCOMPLETE flag set on it so that list traversals ignore it. Once this transaction is committed, a second transaction it run to atomically mark Y as COMPLETE and X as INCOMPLETE, so that a traversal will now find Y and skip X. Once that transaction is committed, attribute X is then removed. So, the initial condition is: +--------+ +--------+ | L1 | | L2 | | fwd: 2 |---->| fwd: 0 | | bwd: 0 |<----| bwd: 1 | | fsp: 0 | | fsp: N | |--------| |--------| | attr A | | attr 1 | |--------| |--------| | attr B | | attr 2 | |--------| |--------| .......... .......... |--------| |--------| | attr X | | attr n | +--------+ +--------+ So now we go to replace X, and see that L1:fsp = 0 - it is full so we can't insert Y in the same leaf. So we record the the location of attribute X so we can track it for later use, then we split L1 into L1 and L3 and reblance across the two leafs. We end with: +--------+ +--------+ +--------+ | L1 | | L3 | | L2 | | fwd: 3 |---->| fwd: 2 |---->| fwd: 0 | | bwd: 0 |<----| bwd: 1 |<----| bwd: 3 | | fsp: M | | fsp: J | | fsp: N | |--------| |--------| |--------| | attr A | | attr X | | attr 1 | |--------| +--------+ |--------| | attr B | | attr 2 | |--------| |--------| .......... .......... |--------| |--------| | attr W | | attr n | +--------+ +--------+ And we track that the original attribute is now at L3:0. We then try to insert Y into L1 again, and find that there isn't enough room because the new attribute is larger than the old one. Hence we have to split again to make room for Y. We end up with this: +--------+ +--------+ +--------+ +--------+ | L1 | | L4 | | L3 | | L2 | | fwd: 4 |---->| fwd: 3 |---->| fwd: 2 |---->| fwd: 0 | | bwd: 0 |<----| bwd: 1 |<----| bwd: 4 |<----| bwd: 3 | | fsp: M | | fsp: J | | fsp: J | | fsp: N | |--------| |--------| |--------| |--------| | attr A | | attr Y | | attr X | | attr 1 | |--------| + INCOMP + +--------+ |--------| | attr B | +--------+ | attr 2 | |--------| |--------| .......... .......... |--------| |--------| | attr W | | attr n | +--------+ +--------+ And now we have the new (incomplete) attribute @ L4:0, and the original attribute at L3:0. At this point, the first transaction is committed, and we move to the flipping of the flags. This is where we are supposed to end up with this: +--------+ +--------+ +--------+ +--------+ | L1 | | L4 | | L3 | | L2 | | fwd: 4 |---->| fwd: 3 |---->| fwd: 2 |---->| fwd: 0 | | bwd: 0 |<----| bwd: 1 |<----| bwd: 4 |<----| bwd: 3 | | fsp: M | | fsp: J | | fsp: J | | fsp: N | |--------| |--------| |--------| |--------| | attr A | | attr Y | | attr X | | attr 1 | |--------| +--------+ + INCOMP + |--------| | attr B | +--------+ | attr 2 | |--------| |--------| .......... .......... |--------| |--------| | attr W | | attr n | +--------+ +--------+ But that doesn't happen properly - the attribute tracking indexes are not pointing to the right locations. What we end up with is both the old attribute to be removed pointing at L4:0 and the new attribute at L4:1. On a debug kernel, this assert fails like so: XFS: Assertion failed: args->index2 < be16_to_cpu(leaf2->hdr.count), file: fs/xfs/xfs_attr_leaf.c, line: 2725 because the new attribute location does not exist. On a production kernel, this goes unnoticed and the code proceeds ahead merrily and removes L4 because it thinks that is the block that is no longer needed. This leaves the hash index node pointing to entries L1, L4 and L2, but only blocks L1, L3 and L2 to exist. Further, the leaf level sibling list is L1 <-> L4 <-> L2, but L4 is now free space, and so everything is busted. This corruption is caused by the removal of the old attribute triggering a join - it joins everything correctly but then frees the wrong block. xfs_repair will report something like: bad sibling back pointer for block 4 in attribute fork for inode 131 problem with attribute contents in inode 131 would clear attr fork bad nblocks 8 for inode 131, would reset to 3 bad anextents 4 for inode 131, would reset to 0 The problem lies in the assignment of the old/new blocks for tracking purposes when the double leaf split occurs. The first split tries to place the new attribute inside the current leaf (i.e. "inleaf == true") and moves the old attribute (X) to the new block. This sets up the old block/index to L1:X, and newly allocated block to L3:0. It then moves attr X to the new block and tries to insert attr Y at the old index. That fails, so it splits again. With the second split, the rebalance ends up placing the new attr in the second new block - L4:0 - and this is where the code goes wrong. What is does is it sets both the new and old block index to the second new block. Hence it inserts attr Y at the right place (L4:0) but overwrites the current location of the attr to replace that is held in the new block index (currently L3:0). It over writes it with L4:1 - the index we later assert fail on. Hopefully this table will show this in a foramt that is a bit easier to understand: Split old attr index new attr index vanilla patched vanilla patched before 1st L1:26 L1:26 N/A N/A after 1st L3:0 L3:0 L1:26 L1:26 after 2nd L4:0 L3:0 L4:1 L4:0 ^^^^ ^^^^ wrong wrong The fix is surprisingly simple, for all this analysis - just stop the rebalance on the out-of leaf case from overwriting the new attr index - it's already correct for the double split case. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-16mm, oom: reintroduce /proc/pid/oom_adjDavid Rientjes
This is mostly a revert of 01dc52ebdf47 ("oom: remove deprecated oom_adj") from Davidlohr Bueso. It reintroduces /proc/pid/oom_adj for backwards compatibility with earlier kernels. It simply scales the value linearly when /proc/pid/oom_score_adj is written. The major difference is that its scheduled removal is no longer included in Documentation/feature-removal-schedule.txt. We do warn users with a single printk, though, to suggest the more powerful and supported /proc/pid/oom_score_adj interface. Reported-by: Artem S. Tashkinov <t.artem@lycos.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-15Merge tag 'upstream-3.7-rc6' of git://git.infradead.org/linux-ubifsLinus Torvalds
Pull UBIFS fixes from Artem Bityutskiy: "Two patches which fix a problem reported by several people in the past, but only fixed now because no one gave enough material for debugging. Anyway, these fix the problem that sometimes after a power cut the file-system is not mountable with the following symptom: grab_empty_leb: could not find an empty LEB The fixes make the file-system mountable again." * tag 'upstream-3.7-rc6' of git://git.infradead.org/linux-ubifs: UBIFS: fix mounting problems after power cuts UBIFS: introduce categorized lprops counter
2012-11-14pstore: Fix NULL pointer dereference in console writesColin Ian King
Passing a NULL id causes a NULL pointer deference in writers such as erst_writer and efi_pstore_write because they expect to update this id. Pass a dummy id instead. This avoids a cascade of oopses caused when the initial pstore_console_write passes a null which in turn causes writes to the console causing further oopses in subsequent pstore_console_write calls. Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
2012-11-12kill bogus BUG_ON() in do_close_on_exec()Al Viro
It can be legitimately triggered via procfs access. Now, at least 2 of 3 of get_files_struct() callers in procfs are useless, but when and if we get rid of those we can always add WARN_ON() here. BUG_ON() at that spot is simply wrong. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-10Merge branch 'for-linus' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull cifs fixes from Jeff Layton. * 'for-linus' of git://git.samba.org/sfrench/cifs-2.6: cifs: Do not lookup hashed negative dentry in cifs_atomic_open cifs: fix potential buffer overrun in cifs.idmap handling code
2012-11-09jffs2: Fix lock acquisition order bug in jffs2_write_beginThomas Betker
jffs2_write_begin() first acquires the page lock, then f->sem. This causes an AB-BA deadlock with jffs2_garbage_collect_live(), which first acquires f->sem, then the page lock: jffs2_garbage_collect_live mutex_lock(&f->sem) (A) jffs2_garbage_collect_dnode jffs2_gc_fetch_page read_cache_page_async do_read_cache_page lock_page(page) (B) jffs2_write_begin grab_cache_page_write_begin find_lock_page lock_page(page) (B) mutex_lock(&f->sem) (A) We fix this by restructuring jffs2_write_begin() to take f->sem before the page lock. However, we make sure that f->sem is not held when calling jffs2_reserve_space(), as this is not permitted by the locking rules. The deadlock above was observed multiple times on an SoC with a dual ARMv7 (Cortex-A9), running the long-term 3.4.11 kernel; it occurred when using scp to copy files from a host system to the ARM target system. The fix was heavily tested on the same target system. Cc: stable@vger.kernel.org Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com> Acked-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
2012-11-09Merge branch 'akpm' (Fixes from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "Five fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (5 patches) h8300: add missing L1_CACHE_SHIFT mm: bugfix: set current->reclaim_state to NULL while returning from kswapd() fanotify: fix missing break revert "epoll: support for disabling items, and a self-test app" checkpatch: improve network block comment style checking
2012-11-09Merge tag 'for-linus-v3.7-rc5' of git://oss.sgi.com/xfs/xfsLinus Torvalds
Pull xfs bugfixes from Ben Myers: - fix for large transactions spanning multiple iclog buffers - zero the allocation_args structure on the stack before using it to determine whether to use a worker for allocation - move allocation stack switch to xfs_bmapi_allocate in order to prevent deadlock on AGF buffers - growfs no longer reads in garbage for new secondary superblocks - silence a build warning - ensure that invalid buffers never get written to disk while on free list - don't vmap inode cluster buffers during free - fix buffer shutdown reference count mismatch - fix reading of wrapped log data * tag 'for-linus-v3.7-rc5' of git://oss.sgi.com/xfs/xfs: xfs: fix reading of wrapped log data xfs: fix buffer shudown reference count mismatch xfs: don't vmap inode cluster buffers during free xfs: invalidate allocbt blocks moved to the free list xfs: silence uninitialised f.file warning. xfs: growfs: don't read garbage for new secondary superblocks xfs: move allocation stack switch up to xfs_bmapi_allocate xfs: introduce XFS_BMAPI_STACK_SWITCH xfs: zero allocation_args on the kernel stack xfs: only update the last_sync_lsn when a transaction completes
2012-11-09fanotify: fix missing breakEric Paris
Anders Blomdell noted in 2010 that Fanotify lost events and provided a test case. Eric Paris confirmed it was a bug and posted a fix to the list https://groups.google.com/forum/?fromgroups=#!topic/linux.kernel/RrJfTfyW2BE but never applied it. Repeated attempts over time to actually get him to apply it have never had a reply from anyone who has raised it So apply it anyway Signed-off-by: Alan Cox <alan@linux.intel.com> Reported-by: Anders Blomdell <anders.blomdell@control.lth.se> Cc: Eric Paris <eparis@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-09revert "epoll: support for disabling items, and a self-test app"Andrew Morton
Revert commit 03a7beb55b9f ("epoll: support for disabling items, and a self-test app") pending resolution of the issues identified by Michael Kerrisk, copied below. We'll revisit this for 3.8. : I've taken a look at this patch as it currently stands in 3.7-rc1, and : done a bit of testing. (By the way, the test program : tools/testing/selftests/epoll/test_epoll.c does not compile...) : : There are one or two places where the behavior seems a little strange, : so I have a question or two at the end of this mail. But other than : that, I want to check my understanding so that the interface can be : correctly documented. : : Just to go though my understanding, the problem is the following : scenario in a multithreaded application: : : 1. Multiple threads are performing epoll_wait() operations, : and maintaining a user-space cache that contains information : corresponding to each file descriptor being monitored by : epoll_wait(). : : 2. At some point, a thread wants to delete (EPOLL_CTL_DEL) : a file descriptor from the epoll interest list, and : delete the corresponding record from the user-space cache. : : 3. The problem with (2) is that some other thread may have : previously done an epoll_wait() that retrieved information : about the fd in question, and may be in the middle of using : information in the cache that relates to that fd. Thus, : there is a potential race. : : 4. The race can't solved purely in user space, because doing : so would require applying a mutex across the epoll_wait() : call, which would of course blow thread concurrency. : : Right? : : Your solution is the EPOLL_CTL_DISABLE operation. I want to : confirm my understanding about how to use this flag, since : the description that has accompanied the patches so far : has been a bit sparse : : 0. In the scenario you're concerned about, deleting a file : descriptor means (safely) doing the following: : (a) Deleting the file descriptor from the epoll interest list : using EPOLL_CTL_DEL : (b) Deleting the corresponding record in the user-space cache : : 1. It's only meaningful to use this EPOLL_CTL_DISABLE in : conjunction with EPOLLONESHOT. : : 2. Using EPOLL_CTL_DISABLE without using EPOLLONESHOT in : conjunction is a logical error. : : 3. The correct way to code multithreaded applications using : EPOLL_CTL_DISABLE and EPOLLONESHOT is as follows: : : a. All EPOLL_CTL_ADD and EPOLL_CTL_MOD operations should : should EPOLLONESHOT. : : b. When a thread wants to delete a file descriptor, it : should do the following: : : [1] Call epoll_ctl(EPOLL_CTL_DISABLE) : [2] If the return status from epoll_ctl(EPOLL_CTL_DISABLE) : was zero, then the file descriptor can be safely : deleted by the thread that made this call. : [3] If the epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY, : then the descriptor is in use. In this case, the calling : thread should set a flag in the user-space cache to : indicate that the thread that is using the descriptor : should perform the deletion operation. : : Is all of the above correct? : : The implementation depends on checking on whether : (events & ~EP_PRIVATE_BITS) == 0 : This replies on the fact that EPOLL_CTL_AD and EPOLL_CTL_MOD always : set EPOLLHUP and EPOLLERR in the 'events' mask, and EPOLLONESHOT : causes those flags (as well as all others in ~EP_PRIVATE_BITS) to be : cleared. : : A corollary to the previous paragraph is that using EPOLL_CTL_DISABLE : is only useful in conjunction with EPOLLONESHOT. However, as things : stand, one can use EPOLL_CTL_DISABLE on a file descriptor that does : not have EPOLLONESHOT set in 'events' This results in the following : (slightly surprising) behavior: : : (a) The first call to epoll_ctl(EPOLL_CTL_DISABLE) returns 0 : (the indicator that the file descriptor can be safely deleted). : (b) The next call to epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY. : : This doesn't seem particularly useful, and in fact is probably an : indication that the user made a logic error: they should only be using : epoll_ctl(EPOLL_CTL_DISABLE) on a file descriptor for which : EPOLLONESHOT was set in 'events'. If that is correct, then would it : not make sense to return an error to user space for this case? Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Paton J. Lewis" <palewis@adobe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-11-08xfs: fix reading of wrapped log dataDave Chinner
Commit 4439647 ("xfs: reset buffer pointers before freeing them") in 3.0-rc1 introduced a regression when recovering log buffers that wrapped around the end of log. The second part of the log buffer at the start of the physical log was being read into the header buffer rather than the data buffer, and hence recovery was seeing garbage in the data buffer when it got to the region of the log buffer that was incorrectly read. Cc: <stable@vger.kernel.org> # 3.0.x, 3.2.x, 3.4.x 3.6.x Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: fix buffer shudown reference count mismatchDave Chinner
When we shut down the filesystem, we have to unpin and free all the buffers currently active in the CIL. To do this we unpin and remove them in one operation as a result of a failed iclogbuf write. For buffers, we do this removal via a simultated IO completion of after marking the buffer stale. At the time we do this, we have two references to the buffer - the active LRU reference and the buf log item. The LRU reference is removed by marking the buffer stale, and the active CIL reference is by the xfs_buf_iodone() callback that is run by xfs_buf_do_callbacks() during ioend processing (via the bp->b_iodone callback). However, ioend processing requires one more reference - that of the IO that it is completing. We don't have this reference, so we free the buffer prematurely and use it after it is freed. For buffers marked with XBF_ASYNC, this leads to assert failures in xfs_buf_rele() on debug kernels because the b_hold count is zero. Fix this by making sure we take the necessary IO reference before starting IO completion processing on the stale buffer, and set the XBF_ASYNC flag to ensure that IO completion processing removes all the active references from the buffer to ensure it is fully torn down. Cc: <stable@vger.kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: don't vmap inode cluster buffers during freeDave Chinner
Inode buffers do not need to be mapped as inodes are read or written directly from/to the pages underlying the buffer. This fixes a regression introduced by commit 611c994 ("xfs: make XBF_MAPPED the default behaviour"). Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: invalidate allocbt blocks moved to the free listDave Chinner
When we free a block from the alloc btree tree, we move it to the freelist held in the AGFL and mark it busy in the busy extent tree. This typically happens when we merge btree blocks. Once the transaction is committed and checkpointed, the block can remain on the free list for an indefinite amount of time. Now, this isn't the end of the world at this point - if the free list is shortened, the buffer is invalidated in the transaction that moves it back to free space. If the buffer is allocated as metadata from the free list, then all the modifications getted logged, and we have no issues, either. And if it gets allocated as userdata direct from the freelist, it gets invalidated and so will never get written. However, during the time it sits on the free list, pressure on the log can cause the AIL to be pushed and the buffer that covers the block gets pushed for write. IOWs, we end up writing a freed metadata block to disk. Again, this isn't the end of the world because we know from the above we are only writing to free space. The problem, however, is for validation callbacks. If the block was on old btree root block, then the level of the block is going to be higher than the current tree root, and so will fail validation. There may be other inconsistencies in the block as well, and currently we don't care because the block is in free space. Shutting down the filesystem because a freed block doesn't pass write validation, OTOH, is rather unfriendly. So, make sure we always invalidate buffers as they move from the free space trees to the free list so that we guarantee they never get written to disk while on the free list. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Phil White <pwhite@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: silence uninitialised f.file warning.Dave Chinner
Uninitialised variable build warning introduced by 2903ff0 ("switch simple cases of fget_light to fdget"), gcc is not smart enough to work out that the variable is not used uninitialised, and the commit removed the initialisation at declaration that the old variable had. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: growfs: don't read garbage for new secondary superblocksDave Chinner
When updating new secondary superblocks in a growfs operation, the superblock buffer is read from the newly grown region of the underlying device. This is not guaranteed to be zero, so violates the underlying assumption that the unused parts of superblocks are zero filled. Get a new buffer for these secondary superblocks to ensure that the unused regions are zero filled correctly. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: move allocation stack switch up to xfs_bmapi_allocateDave Chinner
Switching stacks are xfs_alloc_vextent can cause deadlocks when we run out of worker threads on the allocation workqueue. This can occur because xfs_bmap_btalloc can make multiple calls to xfs_alloc_vextent() and even if xfs_alloc_vextent() fails it can return with the AGF locked in the current allocation transaction. If we then need to make another allocation, and all the allocation worker contexts are exhausted because the are blocked waiting for the AGF lock, holder of the AGF cannot get it's xfs-alloc_vextent work completed to release the AGF. Hence allocation effectively deadlocks. To avoid this, move the stack switch one layer up to xfs_bmapi_allocate() so that all of the allocation attempts in a single switched stack transaction occur in a single worker context. This avoids the problem of an allocation being blocked waiting for a worker thread whilst holding the AGF. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: introduce XFS_BMAPI_STACK_SWITCHDave Chinner
Certain allocation paths through xfs_bmapi_write() are in situations where we have limited stack available. These are almost always in the buffered IO writeback path when convertion delayed allocation extents to real extents. The current stack switch occurs for userdata allocations, which means we also do stack switches for preallocation, direct IO and unwritten extent conversion, even those these call chains have never been implicated in a stack overrun. Hence, let's target just the single stack overun offended for stack switches. To do that, introduce a XFS_BMAPI_STACK_SWITCH flag that the caller can pass xfs_bmapi_write() to indicate it should switch stacks if it needs to do allocation. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: zero allocation_args on the kernel stackMark Tinguely
Zero the kernel stack space that makes up the xfs_alloc_arg structures. Signed-off-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: only update the last_sync_lsn when a transaction completesDave Chinner
The log write code stamps each iclog with the current tail LSN in the iclog header so that recovery knows where to find the tail of thelog once it has found the head. Normally this is taken from the first item on the AIL - the log item that corresponds to the oldest active item in the log. The problem is that when the AIL is empty, the tail lsn is dervied from the the l_last_sync_lsn, which is the LSN of the last iclog to be written to the log. In most cases this doesn't happen, because the AIL is rarely empty on an active filesystem. However, when it does, it opens up an interesting case when the transaction being committed to the iclog spans multiple iclogs. That is, the first iclog is stamped with the l_last_sync_lsn, and IO is issued. Then the next iclog is setup, the changes copied into the iclog (takes some time), and then the l_last_sync_lsn is stamped into the header and IO is issued. This is still the same transaction, so the tail lsn of both iclogs must be the same for log recovery to find the entire transaction to be able to replay it. The problem arises in that the iclog buffer IO completion updates the l_last_sync_lsn with it's own LSN. Therefore, If the first iclog completes it's IO before the second iclog is filled and has the tail lsn stamped in it, it will stamp the LSN of the first iclog into it's tail lsn field. If the system fails at this point, log recovery will not see a complete transaction, so the transaction will no be replayed. The fix is simple - the l_last_sync_lsn is updated when a iclog buffer IO completes, and this is incorrect. The l_last_sync_lsn shoul dbe updated when a transaction is completed by a iclog buffer IO. That is, only iclog buffers that have transaction commit callbacks attached to them should update the l_last_sync_lsn. This means that the last_sync_lsn will only move forward when a commit record it written, not in the middle of a large transaction that is rolling through multiple iclog buffers. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixesLinus Torvalds
Pull gfs2 fixes from Steven Whitehouse: "Here are a number of GFS2 bug fixes. There are three from Andy Price which fix various issues spotted by automated code analysis. There are two from Lukas Czerner fixing my mistaken assumptions as to how FITRIM should work. Finally Ben Marzinski has fixed a bug relating to mmap and atime and also a bug relating to a locking issue in the transaction code." * git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixes: GFS2: Test bufdata with buffer locked and gfs2_log_lock held GFS2: Don't call file_accessed() with a shared glock GFS2: Fix FITRIM argument handling GFS2: Require user to provide argument for FITRIM GFS2: Clean up some unused assignments GFS2: Fix possible null pointer deref in gfs2_rs_alloc GFS2: Fix an unchecked error from gfs2_rs_alloc
2012-11-07GFS2: Test bufdata with buffer locked and gfs2_log_lock heldBenjamin Marzinski
In gfs2_trans_add_bh(), gfs2 was testing if a there was a bd attached to the buffer without having the gfs2_log_lock held. It was then assuming it would stay attached for the rest of the function. However, without either the log lock being held of the buffer locked, __gfs2_ail_flush() could detach bd at any time. This patch moves the locking before the test. If there isn't a bd already attached, gfs2 can safely allocate one and attach it before locking. There is no way that the newly allocated bd could be on the ail list, and thus no way for __gfs2_ail_flush() to detach it. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07GFS2: Don't call file_accessed() with a shared glockBenjamin Marzinski
file_accessed() was being called by gfs2_mmap() with a shared glock. If it needed to update the atime, it was crashing because it dirtied the inode in gfs2_dirty_inode() without holding an exclusive lock. gfs2_dirty_inode() checked if the caller was already holding a glock, but it didn't make sure that the glock was in the exclusive state. Now, instead of calling file_accessed() while holding the shared lock in gfs2_mmap(), file_accessed() is called after grabbing and releasing the glock to update the inode. If file_accessed() needs to update the atime, it will grab an exclusive lock in gfs2_dirty_inode(). gfs2_dirty_inode() now also checks to make sure that if the calling process has already locked the glock, it has an exclusive lock. Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07GFS2: Fix FITRIM argument handlingLukas Czerner
Currently implementation in gfs2 uses FITRIM arguments as it were in file system blocks units which is wrong. The FITRIM arguments (fstrim_range.start, fstrim_range.len and fstrim_range.minlen) are actually in bytes. Moreover, check for start argument beyond the end of file system, len argument being smaller than file system block and minlen argument being bigger than biggest resource group were missing. This commit converts the code to convert FITRIM argument to file system blocks and also adds appropriate checks mentioned above. All the problems were recognised by xfstests 251 and 260. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07GFS2: Require user to provide argument for FITRIMLukas Czerner
When the fstrim_range argument is not provided by user in FITRIM ioctl we should just return EFAULT and not promoting bad behaviour by filling the structure in kernel. Let the user deal with it. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07GFS2: Clean up some unused assignmentsAndrew Price
Cleans up two cases where variables were assigned values but then never used again. Signed-off-by: Andrew Price <anprice@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07GFS2: Fix possible null pointer deref in gfs2_rs_allocAndrew Price
Despite the return value from kmem_cache_zalloc() being checked, the error wasn't being returned until after a possible null pointer dereference. This patch returns the error immediately, allowing the removal of the error variable. Signed-off-by: Andrew Price <anprice@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-07GFS2: Fix an unchecked error from gfs2_rs_allocAndrew Price
Check the return value of gfs2_rs_alloc(ip) and avoid a possible null pointer dereference. Signed-off-by: Andrew Price <anprice@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-11-05cifs: Do not lookup hashed negative dentry in cifs_atomic_openSachin Prabhu
We do not need to lookup a hashed negative directory since we have already revalidated it before and have found it to be fine. This also prevents a crash in cifs_lookup() when it attempts to rehash the already hashed negative lookup dentry. The patch has been tested using the reproducer at https://bugzilla.redhat.com/show_bug.cgi?id=867344#c28 Cc: <stable@kernel.org> # 3.6.x Reported-by: Vit Zahradka <vit.zahradka@tiscali.cz> Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>