linux/fs, branch v3.2.35

jbd: Fix lock ordering bug in journal_unmap_buffer()

2012-12-06T11:20:35Z

commit 25389bb207987b5774182f763b9fb65ff08761c8 upstream. 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. Signed-off-by: Jan Kara Signed-off-by: Ben Hutchings

reiserfs: Move quota calls out of write lock

2012-12-06T11:20:28Z

commit 7af11686933726e99af22901d622f9e161404e6b upstream. 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. Signed-off-by: Jan Kara Signed-off-by: Ben Hutchings

reiserfs: Protect reiserfs_quota_write() with write lock

2012-12-06T11:20:27Z

commit 361d94a338a3fd0cee6a4ea32bbc427ba228e628 upstream. 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. Signed-off-by: Jan Kara Signed-off-by: Ben Hutchings

reiserfs: Protect reiserfs_quota_on() with write lock

2012-12-06T11:20:27Z

commit b9e06ef2e8706fe669b51f4364e3aeed58639eb2 upstream. 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. Signed-off-by: Jan Kara [bwh: Backported to 3.2: there is no distinction between USRQUOTA and GRPQUOTA mount options here] Signed-off-by: Ben Hutchings

reiserfs: Fix lock ordering during remount

2012-12-06T11:20:27Z

commit 3bb3e1fc47aca554e7e2cc4deeddc24750987ac2 upstream. 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. Signed-off-by: Jan Kara [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

xfs: drop buffer io reference when a bad bio is built

2012-12-06T11:20:25Z

commit d69043c42d8c6414fa28ad18d99973aa6c1c2e24 upstream. 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. Signed-off-by: Dave Chinner Reviewed-by: Mark Tinguely Signed-off-by: Ben Myers Signed-off-by: Ben Hutchings

jffs2: Fix lock acquisition order bug in jffs2_write_begin

2012-12-06T11:20:22Z

commit 5ffd3412ae5536a4c57469cb8ea31887121dcb2e upstream. 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. Signed-off-by: Thomas Betker Acked-by: Joakim Tjernlund Signed-off-by: Artem Bityutskiy [bwh: Backported to 3.2: - Adjust context - Use D1(printk(KERN_DEBUG ...)) instead of jffs2_dbg(1, ...)] Signed-off-by: Ben Hutchings

GFS2: Test bufdata with buffer locked and gfs2_log_lock held

2012-12-06T11:20:17Z

commit 96e5d1d3adf56f1c7eeb07258f6a1a0a7ae9c489 upstream. 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 Signed-off-by: Steven Whitehouse [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

UBIFS: fix mounting problems after power cuts

2012-12-06T11:20:01Z

commit a28ad42a4a0c6f302f488f26488b8b37c9b30024 upstream. This is a bugfix for a problem with the following symptoms: 1. A power cut happens 2. After reboot, we try to mount UBIFS 3. Mount fails with "No space left on device" error message UBIFS complains like this: UBIFS error (pid 28225): grab_empty_leb: could not find an empty LEB The root cause of this problem is that when we mount, not all LEBs are categorized. Only those which were read are. However, the 'ubifs_find_free_leb_for_idx()' function assumes that all LEBs were categorized and 'c->freeable_cnt' is valid, which is a false assumption. This patch fixes the problem by teaching 'ubifs_find_free_leb_for_idx()' to always fall back to LPT scanning if no freeable LEBs were found. This problem was reported by few people in the past, but Brent Taylor was able to reproduce it and send me a flash image which cannot be mounted, which made it easy to hunt the bug. Kudos to Brent. Reported-by: Brent Taylor Signed-off-by: Artem Bityutskiy Signed-off-by: Ben Hutchings

UBIFS: introduce categorized lprops counter

2012-12-06T11:20:01Z

commit 98a1eebda3cb2a84ecf1f219bb3a95769033d1bf upstream. This commit is a preparation for a subsequent bugfix. We introduce a counter for categorized lprops. Signed-off-by: Artem Bityutskiy Signed-off-by: Ben Hutchings