user/sven/linux.git/include/linux/jbd2.h, branch v3.4.67

jbd2: fix race between jbd2_journal_remove_checkpoint and ->j_commit_callback

2013-05-08T02:51:57Z

commit 794446c6946513c684d448205fbd76fa35f38b72 upstream. The following race is possible: [kjournald2] other_task jbd2_journal_commit_transaction() j_state = T_FINISHED; spin_unlock(&journal->j_list_lock); ->jbd2_journal_remove_checkpoint() ->jbd2_journal_free_transaction(); ->kmem_cache_free(transaction) ->j_commit_callback(journal, transaction); -> USE_AFTER_FREE WARNING: at lib/list_debug.c:62 __list_del_entry+0x1c0/0x250() Hardware name: list_del corruption. prev->next should be ffff88019a4ec198, but was 6b6b6b6b6b6b6b6b Modules linked in: cpufreq_ondemand acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode sg xhci_hcd button sd_mod crc_t10dif aesni_intel ablk_helper cryptd lrw aes_x86_64 xts gf128mul ahci libahci pata_acpi ata_generic dm_mirror dm_region_hash dm_log dm_mod Pid: 16400, comm: jbd2/dm-1-8 Tainted: G W 3.8.0-rc3+ #107 Call Trace: [] warn_slowpath_common+0xad/0xf0 [] warn_slowpath_fmt+0x46/0x50 [] ? ext4_journal_commit_callback+0x99/0xc0 [] __list_del_entry+0x1c0/0x250 [] ext4_journal_commit_callback+0x6f/0xc0 [] jbd2_journal_commit_transaction+0x23a6/0x2570 [] ? try_to_del_timer_sync+0x82/0xa0 [] ? del_timer_sync+0x91/0x1e0 [] kjournald2+0x19f/0x6a0 [] ? wake_up_bit+0x40/0x40 [] ? bit_spin_lock+0x80/0x80 [] kthread+0x10e/0x120 [] ? __init_kthread_worker+0x70/0x70 [] ret_from_fork+0x7c/0xb0 [] ? __init_kthread_worker+0x70/0x70 In order to demonstrace this issue one should mount ext4 with mount -o discard option on SSD disk. This makes callback longer and race window becomes wider. In order to fix this we should mark transaction as finished only after callbacks have completed Signed-off-by: Dmitry Monakhov Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: make sure the journal sb is written in ext4_clear_journal_err()

2012-08-26T22:00:42Z

commit d796c52ef0b71a988364f6109aeb63d79c5b116b upstream. After we transfer set the EXT4_ERROR_FS bit in the file system superblock, it's not enough to call jbd2_journal_clear_err() to clear the error indication from journal superblock --- we need to call jbd2_journal_update_sb_errno() as well. Otherwise, when the root file system is mounted read-only, the journal is replayed, and the error indicator is transferred to the superblock --- but the s_errno field in the jbd2 superblock is left set (since although we cleared it in memory, we never flushed it out to disk). This can end up confusing e2fsck. We should make e2fsck more robust in this case, but the kernel shouldn't be leaving things in this confused state, either. Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

jbd2: cleanup journal tail after transaction commit

2012-03-14T02:45:38Z

Normally, we have to issue a cache flush before we can update journal tail in journal superblock, effectively wiping out old transactions from the journal. So use the fact that during transaction commit we issue cache flush anyway and opportunistically push journal tail as far as we can. Since update of journal superblock is still costly (we have to use WRITE_FUA), we update log tail only if we can free significant amount of space. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o"

jbd2: issue cache flush after checkpointing even with internal journal

2012-03-14T02:22:54Z

When we reach jbd2_cleanup_journal_tail(), there is no guarantee that checkpointed buffers are on a stable storage - especially if buffers were written out by jbd2_log_do_checkpoint(), they are likely to be only in disk's caches. Thus when we update journal superblock effectively removing old transaction from journal, this write of superblock can get to stable storage before those checkpointed buffers which can result in filesystem corruption after a crash. Thus we must unconditionally issue a cache flush before we update journal superblock in these cases. A similar problem can also occur if journal superblock is written only in disk's caches, other transaction starts reusing space of the transaction cleaned from the log and power failure happens. Subsequent journal replay would still try to replay the old transaction but some of it's blocks may be already overwritten by the new transaction. For this reason we must use WRITE_FUA when updating log tail and we must first write new log tail to disk and update in-memory information only after that. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o"

jbd2: split updating of journal superblock and marking journal empty

2012-03-13T19:41:04Z

There are three case of updating journal superblock. In the first case, we want to mark journal as empty (setting s_sequence to 0), in the second case we want to update log tail, in the third case we want to update s_errno. Split these cases into separate functions. It makes the code slightly more straightforward and later patches will make the distinction even more important. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o"

jbd2: allocate transaction from separate slab cache

2012-02-20T22:53:02Z

There is normally only a handful of these active at any one time, but putting them in a separate slab cache makes debugging memory corruption problems easier. Manish Katiyar also wanted this make it easier to test memory failure scenarios in the jbd2 layer. Cc: Manish Katiyar Signed-off-by: Yongqiang Yang Signed-off-by: "Theodore Ts'o"

jbd2: clear revoked flag on buffers before a new transaction started

2011-12-28T22:46:46Z

Currently, we clear revoked flag only when a block is reused. However, this can tigger a false journal error. Consider a situation when a block is used as a meta block and is deleted(revoked) in ordered mode, then the block is allocated as a data block to a file. At this moment, user changes the file's journal mode from ordered to journaled and truncates the file. The block will be considered re-revoked by journal because it has revoked flag still pending from the last transaction and an assertion triggers. We fix the problem by keeping the revoked status more uptodate - we clear revoked flag when switching revoke tables to reflect there is no revoked buffers in current transaction any more. Signed-off-by: Yongqiang Yang Signed-off-by: "Theodore Ts'o"

jdb/jbd2: factor out common functions from the jbd[2] header files

2011-10-27T08:38:18Z

The state bits and the lock functions of jbd and jbd2 are identical. Share them. Signed-off-by: Thomas Gleixner Signed-off-by: "Theodore Ts'o"

jbd2: use gfp_t instead of int

2011-09-04T14:20:14Z

This silences some Sparse warnings: fs/jbd2/transaction.c:135:69: warning: incorrect type in argument 2 (different base types) fs/jbd2/transaction.c:135:69: expected restricted gfp_t [usertype] flags fs/jbd2/transaction.c:135:69: got int [signed] gfp_mask Signed-off-by: Dan Carpenter Signed-off-by: "Theodore Ts'o"

jbd2: remove jbd2_dev_to_name() from jbd2 tracepoints

2011-07-11T02:05:08Z

Using function calls in TP_printk causes perf heartburn, so print the MAJOR/MINOR device numbers instead. Signed-off-by: "Theodore Ts'o"