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2014-12-01jbd2: fix regression where we fail to initialize checksum seed when loadingDarrick J. Wong
When we're enabling journal features, we cannot use the predicate jbd2_journal_has_csum_v2or3() because we haven't yet set the sb feature flag fields! Moreover, we just finished loading the shash driver, so the test is unnecessary; calculate the seed always. Without this patch, we fail to initialize the checksum seed the first time we turn on journal_checksum, which means that all journal blocks written during that first mount are corrupt. Transactions written after the second mount will be fine, since the feature flag will be set in the journal superblock. xfstests generic/{034,321,322} are the regression tests. (This is important for 3.18.) Signed-off-by: Darrick J. Wong <darrick.wong@oracle.coM> Reported-by: Eric Whitney <enwlinux@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30jbd2: use a better hash function for the revoke tableTheodore Ts'o
The old hash function didn't work well for 64-bit block numbers, and used undefined (negative) shift right behavior. Use the generic 64-bit hash function instead. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com>
2014-09-18jbd2: simplify calling convention around __jbd2_journal_clean_checkpoint_listJan Kara
__jbd2_journal_clean_checkpoint_list() returns number of buffers it freed but noone was using the value so just stop doing that. This also allows for simplifying the calling convention for journal_clean_once_cp_list(). Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-18jbd2: avoid pointless scanning of checkpoint listsJan Kara
Yuanhan has reported that when he is running fsync(2) heavy workload creating new files over ramdisk, significant amount of time is spent in __jbd2_journal_clean_checkpoint_list() trying to clean old transactions (but they cannot be cleaned up because flusher hasn't yet checkpointed those buffers). The workload can be generated by: fs_mark -d /fs/ram0/1 -D 2 -N 2560 -n 1000000 -L 1 -S 1 -s 4096 Reduce the amount of scanning by stopping to scan the transaction list once we find a transaction that cannot be checkpointed. Note that this way of cleaning is still enough to keep freeing space in the journal after fully checkpointed transactions. Reported-and-tested-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-16jbd2: jbd2_log_wait_for_space improve error detetcionDmitry Monakhov
If EIO happens after we have dropped j_state_lock, we won't notice that the journal has been aborted. So it is reasonable to move this check after we have grabbed the j_checkpoint_mutex and re-grabbed the j_state_lock. This patch helps to prevent false positive complain after EIO. #DMESG: __jbd2_log_wait_for_space: needed 8448 blocks and only had 8386 space available __jbd2_log_wait_for_space: no way to get more journal space in ram1-8 ------------[ cut here ]------------ WARNING: CPU: 15 PID: 6739 at fs/jbd2/checkpoint.c:168 __jbd2_log_wait_for_space+0x188/0x200() Modules linked in: brd iTCO_wdt lpc_ich mfd_core igb ptp dm_mirror dm_region_hash dm_log dm_mod CPU: 15 PID: 6739 Comm: fsstress Tainted: G W 3.17.0-rc2-00429-g684de57 #139 Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011 00000000000000a8 ffff88077aaab878 ffffffff815c1a8c 00000000000000a8 0000000000000000 ffff88077aaab8b8 ffffffff8106ce8c ffff88077aaab898 ffff8807c57e6000 ffff8807c57e6028 0000000000002100 ffff8807c57e62f0 Call Trace: [<ffffffff815c1a8c>] dump_stack+0x51/0x6d [<ffffffff8106ce8c>] warn_slowpath_common+0x8c/0xc0 [<ffffffff8106ceda>] warn_slowpath_null+0x1a/0x20 [<ffffffff812419f8>] __jbd2_log_wait_for_space+0x188/0x200 [<ffffffff8123be9a>] start_this_handle+0x4da/0x7b0 [<ffffffff810990e5>] ? local_clock+0x25/0x30 [<ffffffff810aba87>] ? lockdep_init_map+0xe7/0x180 [<ffffffff8123c5bc>] jbd2__journal_start+0xdc/0x1d0 [<ffffffff811f2414>] ? __ext4_new_inode+0x7f4/0x1330 [<ffffffff81222a38>] __ext4_journal_start_sb+0xf8/0x110 [<ffffffff811f2414>] __ext4_new_inode+0x7f4/0x1330 [<ffffffff810ac359>] ? lock_release_holdtime+0x29/0x190 [<ffffffff812025bb>] ext4_create+0x8b/0x150 [<ffffffff8117fe3b>] vfs_create+0x7b/0xb0 [<ffffffff8118097b>] do_last+0x7db/0xcf0 [<ffffffff8117e31d>] ? inode_permission+0x4d/0x50 [<ffffffff811845d2>] path_openat+0x242/0x590 [<ffffffff81191a76>] ? __alloc_fd+0x36/0x140 [<ffffffff81184a6a>] do_filp_open+0x4a/0xb0 [<ffffffff81191b61>] ? __alloc_fd+0x121/0x140 [<ffffffff81172f20>] do_sys_open+0x170/0x220 [<ffffffff8117300e>] SyS_open+0x1e/0x20 [<ffffffff811715d6>] SyS_creat+0x16/0x20 [<ffffffff815c7e12>] system_call_fastpath+0x16/0x1b ---[ end trace cd71c831f82059db ]--- Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-16jbd2: free bh when descriptor block checksum failsDarrick J. Wong
Free the buffer head if the journal descriptor block fails checksum verification. This is the jbd2 port of the e2fsprogs patch "e2fsck: free bh on csum verify error in do_one_pass". Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Cc: stable@vger.kernel.org
2014-09-11jbd2: fix journal checksum feature flag handlingDarrick J. Wong
Clear all three journal checksum feature flags before turning on whichever journal checksum options we want. Rearrange the error checking so that newer flags get complained about first. Reported-by: TR Reardon <thomas_reardon@hotmail.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-04jbd/jbd2: use non-movable memory for the jbd superblockGioh Kim
Sicne the jbd/jbd2 superblock is not released until the file system is unmounted, allocate the buffer cache from the non-moveable area to allow page migration and CMA allocations to more easily succeed. Signed-off-by: Gioh Kim <gioh.kim@lge.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2014-09-04jbd2: optimize jbd2_log_do_checkpoint() a bitJan Kara
When we discover written out buffer in transaction checkpoint list we don't have to recheck validity of a transaction. Either this is the last buffer in a transaction - and then we are done - or this isn't and then we can just take another buffer from the checkpoint list without dropping j_list_lock. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-04jbd2: don't call get_bh() before calling __jbd2_journal_remove_checkpoint()Theodore Ts'o
The __jbd2_journal_remove_checkpoint() doesn't require an elevated b_count; indeed, until the jh structure gets released by the call to jbd2_journal_put_journal_head(), the bh's b_count is elevated by virtue of the existence of the jh structure. Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01jbd2: fold __wait_cp_io into jbd2_log_do_checkpoint()Theodore Ts'o
__wait_cp_io() is only called by jbd2_log_do_checkpoint(). Fold it in to make it a bit easier to understand. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-09-01jbd2: fold __process_buffer() into jbd2_log_do_checkpoint()Theodore Ts'o
__process_buffer() is only called by jbd2_log_do_checkpoint(), and it had a very complex locking protocol where it would be called with the j_list_lock, and sometimes exit with the lock held (if the return code was 0), or release the lock. This was confusing both to humans and to smatch (which erronously complained that the lock was taken twice). Folding __process_buffer() to the caller allows us to simplify the control flow, making the resulting function easier to read and reason about, and dropping the compiled size of fs/jbd2/checkpoint.c by 150 bytes (over 4% of the text size). Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2014-08-28jbd2: fix descriptor block size handling errors with journal_csumDarrick J. Wong
It turns out that there are some serious problems with the on-disk format of journal checksum v2. The foremost is that the function to calculate descriptor tag size returns sizes that are too big. This causes alignment issues on some architectures and is compounded by the fact that some parts of jbd2 use the structure size (incorrectly) to determine the presence of a 64bit journal instead of checking the feature flags. Therefore, introduce journal checksum v3, which enlarges the descriptor block tag format to allow for full 32-bit checksums of journal blocks, fix the journal tag function to return the correct sizes, and fix the jbd2 recovery code to use feature flags to determine 64bitness. Add a few function helpers so we don't have to open-code quite so many pieces. Switching to a 16-byte block size was found to increase journal size overhead by a maximum of 0.1%, to convert a 32-bit journal with no checksumming to a 32-bit journal with checksum v3 enabled. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reported-by: TR Reardon <thomas_reardon@hotmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2014-08-28jbd2: fix infinite loop when recovering corrupt journal blocksDarrick J. Wong
When recovering the journal, don't fall into an infinite loop if we encounter a corrupt journal block. Instead, just skip the block and return an error, which fails the mount and thus forces the user to run a full filesystem fsck. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2014-07-16sched: Remove proliferation of wait_on_bit() action functionsNeilBrown
The current "wait_on_bit" interface requires an 'action' function to be provided which does the actual waiting. There are over 20 such functions, many of them identical. Most cases can be satisfied by one of just two functions, one which uses io_schedule() and one which just uses schedule(). So: Rename wait_on_bit and wait_on_bit_lock to wait_on_bit_action and wait_on_bit_lock_action to make it explicit that they need an action function. Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io which are *not* given an action function but implicitly use a standard one. The decision to error-out if a signal is pending is now made based on the 'mode' argument rather than being encoded in the action function. All instances of the old wait_on_bit and wait_on_bit_lock which can use the new version have been changed accordingly and their action functions have been discarded. wait_on_bit{_lock} does not return any specific error code in the event of a signal so the caller must check for non-zero and interpolate their own error code as appropriate. The wait_on_bit() call in __fscache_wait_on_invalidate() was ambiguous as it specified TASK_UNINTERRUPTIBLE but used fscache_wait_bit_interruptible as an action function. David Howells confirms this should be uniformly "uninterruptible" The main remaining user of wait_on_bit{,_lock}_action is NFS which needs to use a freezer-aware schedule() call. A comment in fs/gfs2/glock.c notes that having multiple 'action' functions is useful as they display differently in the 'wchan' field of 'ps'. (and /proc/$PID/wchan). As the new bit_wait{,_io} functions are tagged "__sched", they will not show up at all, but something higher in the stack. So the distinction will still be visible, only with different function names (gds2_glock_wait versus gfs2_glock_dq_wait in the gfs2/glock.c case). Since first version of this patch (against 3.15) two new action functions appeared, on in NFS and one in CIFS. CIFS also now uses an action function that makes the same freezer aware schedule call as NFS. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: David Howells <dhowells@redhat.com> (fscache, keys) Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2) Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steve French <sfrench@samba.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-07-05ext4: disable synchronous transaction batching if max_batch_time==0Eric Sandeen
The mount manpage says of the max_batch_time option, This optimization can be turned off entirely by setting max_batch_time to 0. But the code doesn't do that. So fix the code to do that. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2014-04-18arch: Mass conversion of smp_mb__*()Peter Zijlstra
Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-03-12jbd2: improve error messages for inconsistent journal headsTheodore Ts'o
Fix up error messages printed when the transaction pointers in a journal head are inconsistent. This improves the error messages which are printed when running xfstests generic/068 in data=journal mode. See the bug report at: https://bugzilla.kernel.org/show_bug.cgi?id=60786 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-09jbd2: minimize region locked by j_list_lock in jbd2_journal_forget()Theodore Ts'o
It's not needed until we start trying to modifying fields in the journal_head which are protected by j_list_lock. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-09jbd2: minimize region locked by j_list_lock in journal_get_create_access()Theodore Ts'o
It's not needed until we start trying to modifying fields in the journal_head which are protected by j_list_lock. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-09jbd2: check jh->b_transaction without taking j_list_lockTheodore Ts'o
jh->b_transaction is adequately protected for reading by the jbd_lock_bh_state(bh), so we don't need to take j_list_lock in __journal_try_to_free_buffer(). Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-08jbd2: add transaction to checkpoint list earlierTheodore Ts'o
We don't otherwise need j_list_lock during the rest of commit phase #7, so add the transaction to the checkpoint list at the very end of commit phase #6. This allows us to drop j_list_lock earlier, which is a good thing since it is a super hot lock. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-08jbd2: calculate statistics without holding j_state_lock and j_list_lockTheodore Ts'o
The two hottest locks, and thus the biggest scalability bottlenecks, in the jbd2 layer, are the j_list_lock and j_state_lock. This has inspired some people to do some truly unnatural things[1]. [1] https://www.usenix.org/system/files/conference/fast14/fast14-paper_kang.pdf We don't need to be holding both j_state_lock and j_list_lock while calculating the journal statistics, so move those calculations to the very end of jbd2_journal_commit_transaction. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-08jbd2: don't hold j_state_lock while calling wake_up()Theodore Ts'o
The j_state_lock is one of the hottest locks in the jbd2 layer and thus one of its scalability bottlenecks. We don't need to be holding the j_state_lock while we are calling wake_up(&journal->j_wait_commit), so release the lock a little bit earlier. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-03-08jbd2: don't unplug after writing revoke recordsTheodore Ts'o
During commit process, keep the block device plugged after we are done writing the revoke records, until we are finished writing the rest of the commit records in the journal. This will allow most of the journal blocks to be written in a single I/O operation, instead of separating the the revoke blocks from the rest of the journal blocks. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-02-17jbd2: mark file-local functions as staticRashika Kheria
Mark functions as static in jbd2/journal.c because they are not used outside this file. This eliminates the following warning in jbd2/journal.c: fs/jbd2/journal.c:125:5: warning: no previous prototype for ‘jbd2_verify_csum_type’ [-Wmissing-prototypes] fs/jbd2/journal.c:146:5: warning: no previous prototype for ‘jbd2_superblock_csum_verify’ [-Wmissing-prototypes] fs/jbd2/journal.c:154:6: warning: no previous prototype for ‘jbd2_superblock_csum_set’ [-Wmissing-prototypes] Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
2014-02-17jbd2: fix use after free in jbd2_journal_start_reserved()Dan Carpenter
If start_this_handle() fails then it leads to a use after free of "handle". Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2013-12-08jbd2: rename obsoleted msg JBD->JBD2Dmitry Monakhov
Rename performed via: perl -pi -e 's/JBD:/JBD2:/g' fs/jbd2/*.c Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2013-12-08jbd2: revise KERN_EMERG error messagesJan Kara
Some of KERN_EMERG printk messages do not really deserve this log level and the one in log_wait_commit() is even rather useless (the journal has been previously aborted and *that* is where we should have been complaining). So make some messages just KERN_ERR and remove the useless message. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-12-08jbd2: don't BUG but return ENOSPC if a handle runs out of spaceTheodore Ts'o
If a handle runs out of space, we currently stop the kernel with a BUG in jbd2_journal_dirty_metadata(). This makes it hard to figure out what might be going on. So return an error of ENOSPC, so we can let the file system layer figure out what is going on, to make it more likely we can get useful debugging information). This should make it easier to debug problems such as the one which was reported by: https://bugzilla.kernel.org/show_bug.cgi?id=44731 The only two callers of this function are ext4_handle_dirty_metadata() and ocfs2_journal_dirty(). The ocfs2 function will trigger a BUG_ON(), which means there will be no change in behavior. The ext4 function will call ext4_error_inode() which will print the useful debugging information and then handle the situation using ext4's error handling mechanisms (i.e., which might mean halting the kernel or remounting the file system read-only). Also, since both file systems already call WARN_ON(), drop the WARN_ON from jbd2_journal_dirty_metadata() to avoid two stack traces from being displayed. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: ocfs2-devel@oss.oracle.com Acked-by: Joel Becker <jlbec@evilplan.org>
2013-08-28jbd2: Fix endian mixing problems in the checksumming codeDarrick J. Wong
In the jbd2 checksumming code, explicitly declare separate variables with endianness information so that we don't get confused and screw things up again. Also fixes sparse warnings. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-01jbd2: invalidate handle if jbd2_journal_restart() failsTheodore Ts'o
If jbd2_journal_restart() fails the handle will have been disconnected from the current transaction. In this situation, the handle must not be used for for any jbd2 function other than jbd2_journal_stop(). Enforce this with by treating a handle which has a NULL transaction pointer as an aborted handle, and issue a kernel warning if jbd2_journal_extent(), jbd2_journal_get_write_access(), jbd2_journal_dirty_metadata(), etc. is called with an invalid handle. This commit also fixes a bug where jbd2_journal_stop() would trip over a kernel jbd2 assertion check when trying to free an invalid handle. Also move the responsibility of setting current->journal_info to start_this_handle(), simplifying the three users of this function. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reported-by: Younger Liu <younger.liu@huawei.com> Cc: Jan Kara <jack@suse.cz>
2013-07-01jbd2: fix theoretical race in jbd2__journal_restartTheodore Ts'o
Once we decrement transaction->t_updates, if this is the last handle holding the transaction from closing, and once we release the t_handle_lock spinlock, it's possible for the transaction to commit and be released. In practice with normal kernels, this probably won't happen, since the commit happens in a separate kernel thread and it's unlikely this could all happen within the space of a few CPU cycles. On the other hand, with a real-time kernel, this could potentially happen, so save the tid found in transaction->t_tid before we release t_handle_lock. It would require an insane configuration, such as one where the jbd2 thread was set to a very high real-time priority, perhaps because a high priority real-time thread is trying to read or write to a file system. But some people who use real-time kernels have been known to do insane things, including controlling laser-wielding industrial robots. :-) Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2013-07-01jbd2: move superblock checksum calculation to jbd2_write_superblock()Theodore Ts'o
Some of the functions which modify the jbd2 superblock were not updating the checksum before calling jbd2_write_superblock(). Move the call to jbd2_superblock_csum_set() to jbd2_write_superblock(), so that the checksum is calculated consistently. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: stable@vger.kernel.org
2013-06-12jbd2: remove debug dependency on debug_fs and update Kconfig help textPaul Gortmaker
Commit b6e96d0067d8 ("jbd2: use module parameters instead of debugfs for jbd_debug") removed any need for a dependency on DEBUG_FS. It also moved the /sys variables out from underneath the typical debugfs mount point. Delete the dependency and update the /sys path to where the debug settings are currently. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-12jbd2: use a single printk for jbd_debug()Paul Gortmaker
Since the jbd_debug() is implemented with two separate printk() calls, it can lead to corrupted and misleading debug output like the following (see lines marked with "*"): [ 290.339362] (fs/jbd2/journal.c, 203): kjournald2: kjournald2 wakes [ 290.339365] (fs/jbd2/journal.c, 155): kjournald2: commit_sequence=42103, commit_request=42104 [ 290.339369] (fs/jbd2/journal.c, 158): kjournald2: OK, requests differ [* 290.339376] (fs/jbd2/journal.c, 648): jbd2_log_wait_commit: [* 290.339379] (fs/jbd2/commit.c, 370): jbd2_journal_commit_transaction: JBD2: want 42104, j_commit_sequence=42103 [* 290.339382] JBD2: starting commit of transaction 42104 [ 290.339410] (fs/jbd2/revoke.c, 566): jbd2_journal_write_revoke_records: Wrote 0 revoke records [ 290.376555] (fs/jbd2/commit.c, 1088): jbd2_journal_commit_transaction: JBD2: commit 42104 complete, head 42079 i.e. the debug output from log_wait_commit and journal_commit_transaction have become interleaved. The output should have been: (fs/jbd2/journal.c, 648): jbd2_log_wait_commit: JBD2: want 42104, j_commit_sequence=42103 (fs/jbd2/commit.c, 370): jbd2_journal_commit_transaction: JBD2: starting commit of transaction 42104 It is expected that this is not easy to replicate -- I was only able to cause it on preempt-rt kernels, and even then only under heavy I/O load. Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Suggested-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-12jbd2: fix duplicate debug label for phase 2Paul Gortmaker
Currently we see this output: $git grep phase fs/jbd2 fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 1\n"); fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 2\n"); fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 2\n"); fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 3\n"); fs/jbd2/commit.c: jbd_debug(3, "JBD2: commit phase 4\n"); [...] There is clearly a duplicate label for phase 2, and they are both active (i.e. not in #if ... #else block). Rename them to be "2a" and "2b" so the debug output is unambiguous. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-12jbd2: drop checkpoint mutex when waiting in __jbd2_log_wait_for_space()Paul Gortmaker
While trying to debug an an issue under extreme I/O loading on preempt-rt kernels, the following backtrace was observed via SysRQ output: rm D ffff8802203afbc0 4600 4878 4748 0x00000000 ffff8802217bfb78 0000000000000082 ffff88021fc2bb80 ffff88021fc2bb80 ffff88021fc2bb80 ffff8802217bffd8 ffff8802217bffd8 ffff8802217bffd8 ffff88021f1d4c80 ffff88021fc2bb80 ffff8802217bfb88 ffff88022437b000 Call Trace: [<ffffffff8172dc34>] schedule+0x24/0x70 [<ffffffff81225b5d>] jbd2_log_wait_commit+0xbd/0x140 [<ffffffff81060390>] ? __init_waitqueue_head+0x50/0x50 [<ffffffff81223635>] jbd2_log_do_checkpoint+0xf5/0x520 [<ffffffff81223b09>] __jbd2_log_wait_for_space+0xa9/0x1f0 [<ffffffff8121dc40>] start_this_handle.isra.10+0x2e0/0x530 [<ffffffff81060390>] ? __init_waitqueue_head+0x50/0x50 [<ffffffff8121e0a3>] jbd2__journal_start+0xc3/0x110 [<ffffffff811de7ce>] ? ext4_rmdir+0x6e/0x230 [<ffffffff8121e0fe>] jbd2_journal_start+0xe/0x10 [<ffffffff811f308b>] ext4_journal_start_sb+0x5b/0x160 [<ffffffff811de7ce>] ext4_rmdir+0x6e/0x230 [<ffffffff811435c5>] vfs_rmdir+0xd5/0x140 [<ffffffff8114370f>] do_rmdir+0xdf/0x120 [<ffffffff8105c6b4>] ? task_work_run+0x44/0x80 [<ffffffff81002889>] ? do_notify_resume+0x89/0x100 [<ffffffff817361ae>] ? int_signal+0x12/0x17 [<ffffffff81145d85>] sys_unlinkat+0x25/0x40 [<ffffffff81735f22>] system_call_fastpath+0x16/0x1b What is interesting here, is that we call log_wait_commit, from within wait_for_space, but we are still holding the checkpoint_mutex as it surrounds mostly the whole of wait_for_space. And then, as we are waiting, journal_commit_transaction can run, and if the JBD2_FLUSHED bit is set, then we will also try to take the same checkpoint_mutex. It seems that we need to drop the checkpoint_mutex while sitting in jbd2_log_wait_commit, if we want to guarantee that progress can be made by jbd2_journal_commit_transaction(). There does not seem to be anything preempt-rt specific about this, other then perhaps increasing the odds of it happening. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-12jbd2: relocate assert after state lock in journal_commit_transaction()Paul Gortmaker
The state lock is taken after we are doing an assert on the state value, not before. So we might in fact be doing an assert on a transient value. Ensure the state check is within the scope of the state lock being taken. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-12jbd2: optimize jbd2_journal_force_commitDmitry Monakhov
Current implementation of jbd2_journal_force_commit() is suboptimal because result in empty and useless commits. But callers just want to force and wait any unfinished commits. We already have jbd2_journal_force_commit_nested() which does exactly what we want, except we are guaranteed that we do not hold journal transaction open. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04jbd2: transaction reservation supportJan Kara
In some cases we cannot start a transaction because of locking constraints and passing started transaction into those places is not handy either because we could block transaction commit for too long. Transaction reservation is designed to solve these issues. It reserves a handle with given number of credits in the journal and the handle can be later attached to the running transaction without blocking on commit or checkpointing. Reserved handles do not block transaction commit in any way, they only reduce maximum size of the running transaction (because we have to always be prepared to accomodate request for attaching reserved handle). Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04jbd2: remove unused waitqueuesJan Kara
j_wait_logspace and j_wait_checkpoint are unused. Remove them. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04jbd2: fix race in t_outstanding_credits update in jbd2_journal_extend()Jan Kara
jbd2_journal_extend() first checked whether transaction can accept extending handle with more credits and then added credits to t_outstanding_credits. This can race with start_this_handle() adding another handle to a transaction and thus overbooking a transaction. Make jbd2_journal_extend() use atomic_add_return() to close the race. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04jbd2: cleanup needed free block estimates when starting a transactionJan Kara
__jbd2_log_space_left() and jbd_space_needed() were kind of odd. jbd_space_needed() accounted also credits needed for currently committing transaction while it didn't account for credits needed for control blocks. __jbd2_log_space_left() then accounted for control blocks as a fraction of free space. Since results of these two functions are always only compared against each other, this works correct but is somewhat strange. Move the estimates so that jbd_space_needed() returns number of blocks needed for a transaction including control blocks and __jbd2_log_space_left() returns free space in the journal (with the committing transaction already subtracted). Rename functions to jbd2_log_space_left() and jbd2_space_needed() while we are changing them. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04jbd2: remove outdated commentJan Kara
The comment about credit estimates isn't true anymore. We do what the comment describes now. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04jbd2: refine waiting for shadow buffersJan Kara
Currently when we add a buffer to a transaction, we wait until the buffer is removed from BJ_Shadow list (so that we prevent any changes to the buffer that is just written to the journal). This can take unnecessarily long as a lot happens between the time the buffer is submitted to the journal and the time when we remove the buffer from BJ_Shadow list. (e.g. We wait for all data buffers in the transaction, we issue a cache flush, etc.) Also this creates a dependency of do_get_write_access() on transaction commit (namely waiting for data IO to complete) which we want to avoid when implementing transaction reservation. So we modify commit code to set new BH_Shadow flag when temporary shadowing buffer is created and we clear that flag once IO on that buffer is complete. This allows do_get_write_access() to wait only for BH_Shadow bit and thus removes the dependency on data IO completion. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04jbd2: remove journal_head from descriptor buffersJan Kara
Similarly as for metadata buffers, also log descriptor buffers don't really need the journal head. So strip it and remove BJ_LogCtl list. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-06-04jbd2: don't create journal_head for temporary journal buffersJan Kara
When writing metadata to the journal, we create temporary buffer heads for that task. We also attach journal heads to these buffer heads but the only purpose of the journal heads is to keep buffers linked in transaction's BJ_IO list. We remove the need for journal heads by reusing buffer_head's b_assoc_buffers list for that purpose. Also since BJ_IO list is just a temporary list for transaction commit, we use a private list in jbd2_journal_commit_transaction() for that thus removing BJ_IO list from transaction completely. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-05-28jbd2: fix block tag checksum verification brokennessDarrick J. Wong
Al Viro complained of a ton of bogosity with regards to the jbd2 block tag header checksum. This one checksum is 16 bits, so cut off the upper 16 bits and treat it as a 16-bit value and don't mess around with be32* conversions. Fortunately metadata checksumming is still "experimental" and not in a shipping e2fsprogs, so there should be few users affected by this. Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2013-05-28jbd2: use kmem_cache_zalloc for allocating journal headZheng Liu
This commit tries to use kmem_cache_zalloc instead of kmem_cache_alloc/ memset when a new journal head is alloctated. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Cc: "Theodore Ts'o" <tytso@mit.edu>