linux/fs/ext4, branch v3.4.19

ext4: fix unjournaled inode bitmap modification

2012-11-05T08:50:41Z

commit ffb5387e85d528fb6d0d924abfa3fbf0fc484071 upstream. commit 119c0d4460b001e44b41dcf73dc6ee794b98bd31 changed ext4_new_inode() such that the inode bitmap was being modified outside a transaction, which could lead to corruption, and was discovered when journal_checksum found a bad checksum in the journal during log replay. Nix ran into this when using the journal_async_commit mount option, which enables journal checksumming. The ensuing journal replay failures due to the bad checksums led to filesystem corruption reported as the now infamous "Apparent serious progressive ext4 data corruption bug" [ Changed by tytso to only call ext4_journal_get_write_access() only when we're fairly certain that we're going to allocate the inode. ] I've tested this by mounting with journal_checksum and running fsstress then dropping power; I've also tested by hacking DM to create snapshots w/o first quiescing, which allows me to test journal replay repeatedly w/o actually power-cycling the box. Without the patch I hit a journal checksum error every time. With this fix it survives many iterations. Reported-by: Nix Signed-off-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: Avoid underflow in ext4_trim_fs()

2012-10-28T17:14:12Z

commit 5de35e8d5c02d271c20e18337e01bc20e6ef472e upstream. Currently if len argument in ext4_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 Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: race-condition protection for ext4_convert_unwritten_extents_endio

2012-10-28T17:14:12Z

commit dee1f973ca341c266229faa5a1a5bb268bed3531 upstream. We assumed that at the time we call ext4_convert_unwritten_extents_endio() extent in question is fully inside [map.m_lblk, map->m_len] because it was already split during submission. But this may not be true due to a race between writeback vs fallocate. If extent in question is larger than requested we will split it again. Special precautions should being done if zeroout required because [map.m_lblk, map->m_len] already contains valid data. Signed-off-by: Dmitry Monakhov Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix fdatasync() for files with only i_size changes

2012-10-12T20:38:50Z

commit b71fc079b5d8f42b2a52743c8d2f1d35d655b1c5 upstream. Code tracking when transaction needs to be committed on fdatasync(2) forgets to handle a situation when only inode's i_size is changed. Thus in such situations fdatasync(2) doesn't force transaction with new i_size to disk and that can result in wrong i_size after a crash. Fix the issue by updating inode's i_datasync_tid whenever its size is updated. Reported-by: Kristian Nielsen Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

ext4: always set i_op in ext4_mknod()

2012-10-12T20:38:49Z

commit 6a08f447facb4f9e29fcc30fb68060bb5a0d21c2 upstream. ext4_special_inode_operations have their own ifdef CONFIG_EXT4_FS_XATTR to mask those methods. And ext4_iget also always sets it, so there is an inconsistency. Signed-off-by: Bernd Schubert Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: online defrag is not supported for journaled files

2012-10-12T20:38:49Z

commit f066055a3449f0e5b0ae4f3ceab4445bead47638 upstream. Proper block swap for inodes with full journaling enabled is truly non obvious task. In order to be on a safe side let's explicitly disable it for now. Signed-off-by: Dmitry Monakhov Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: move_extent code cleanup

2012-10-12T20:38:49Z

commit 03bd8b9b896c8e940f282f540e6b4de90d666b7c upstream. - Remove usless checks, because it is too late to check that inode != NULL at the moment it was referenced several times. - Double lock routines looks very ugly and locking ordering relays on order of i_ino, but other kernel code rely on order of pointers. Let's make them simple and clean. - check that inodes belongs to the same SB as soon as possible. Signed-off-by: Dmitry Monakhov Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix crash when accessing /proc/mounts concurrently

2012-10-12T20:38:49Z

commit 50df9fd55e4271e89a7adf3b1172083dd0ca199d upstream. The crash was caused by a variable being erronously declared static in token2str(). In addition to /proc/mounts, the problem can also be easily replicated by accessing /proc/fs/ext4//options in parallel: $ cat /proc/fs/ext4//options > options.txt ... and then running the following command in two different terminals: $ while diff /proc/fs/ext4//options options.txt; do true; done This is also the cause of the following a crash while running xfstests #234, as reported in the following bug reports: https://bugs.launchpad.net/bugs/1053019 https://bugzilla.kernel.org/show_bug.cgi?id=47731 Signed-off-by: Herton Ronaldo Krzesinski Signed-off-by: "Theodore Ts'o" Cc: Brad Figg Signed-off-by: Greg Kroah-Hartman

ext4: fix potential deadlock in ext4_nonda_switch()

2012-10-12T20:38:49Z

commit 00d4e7362ed01987183e9528295de3213031309c upstream. In ext4_nonda_switch(), if the file system is getting full we used to call writeback_inodes_sb_if_idle(). The problem is that we can be holding i_mutex already, and this causes a potential deadlock when writeback_inodes_sb_if_idle() when it tries to take s_umount. (See lockdep output below). As it turns out we don't need need to hold s_umount; the fact that we are in the middle of the write(2) system call will keep the superblock pinned. Unfortunately writeback_inodes_sb() checks to make sure s_umount is taken, and the VFS uses a different mechanism for making sure the file system doesn't get unmounted out from under us. The simplest way of dealing with this is to just simply grab s_umount using a trylock, and skip kicking the writeback flusher thread in the very unlikely case that we can't take a read lock on s_umount without blocking. Also, we now check the cirteria for kicking the writeback thread before we decide to whether to fall back to non-delayed writeback, so if there are any outstanding delayed allocation writes, we try to get them resolved as soon as possible. [ INFO: possible circular locking dependency detected ] 3.6.0-rc1-00042-gce894ca #367 Not tainted ------------------------------------------------------- dd/8298 is trying to acquire lock: (&type->s_umount_key#18){++++..}, at: [] writeback_inodes_sb_if_idle+0x28/0x46 but task is already holding lock: (&sb->s_type->i_mutex_key#8){+.+...}, at: [] generic_file_aio_write+0x5f/0xd3 which lock already depends on the new lock. 2 locks held by dd/8298: #0: (sb_writers#2){.+.+.+}, at: [] generic_file_aio_write+0x56/0xd3 #1: (&sb->s_type->i_mutex_key#8){+.+...}, at: [] generic_file_aio_write+0x5f/0xd3 stack backtrace: Pid: 8298, comm: dd Not tainted 3.6.0-rc1-00042-gce894ca #367 Call Trace: [] ? console_unlock+0x345/0x372 [] print_circular_bug+0x190/0x19d [] __lock_acquire+0x86d/0xb6c [] ? mark_held_locks+0x5c/0x7b [] lock_acquire+0x66/0xb9 [] ? writeback_inodes_sb_if_idle+0x28/0x46 [] down_read+0x28/0x58 [] ? writeback_inodes_sb_if_idle+0x28/0x46 [] writeback_inodes_sb_if_idle+0x28/0x46 [] ext4_nonda_switch+0xe1/0xf4 [] ext4_da_write_begin+0x27/0x193 [] generic_file_buffered_write+0xc8/0x1bb [] __generic_file_aio_write+0x1dd/0x205 [] generic_file_aio_write+0x78/0xd3 [] ext4_file_write+0x480/0x4a6 [] ? __lock_acquire+0x41e/0xb6c [] ? sched_clock_cpu+0x11a/0x13e [] ? trace_hardirqs_off+0xb/0xd [] ? local_clock+0x37/0x4e [] do_sync_write+0x67/0x9d [] ? wait_on_retry_sync_kiocb+0x44/0x44 [] vfs_write+0x7b/0xe6 [] sys_write+0x3b/0x64 [] syscall_call+0x7/0xb Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: avoid duplicate writes of the backup bg descriptor blocks

2012-10-12T20:38:48Z

commit 2ebd1704ded88a8ae29b5f3998b13959c715c4be upstream. The resize code was needlessly writing the backup block group descriptor blocks multiple times (once per block group) during an online resize. Signed-off-by: Yongqiang Yang Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman