kernel.git/fs/ext4/mballoc.c, branch linux-3.17.y

ext4: fix BUG_ON in mb_free_blocks()

2014-08-23T21:47:28Z

If we suffer a block allocation failure (for example due to a memory allocation failure), it's possible that we will call ext4_discard_allocated_blocks() before we've actually allocated any blocks. In that case, fe_len and fe_start in ac->ac_f_ex will still be zero, and this will result in mb_free_blocks(inode, e4b, 0, 0) triggering the BUG_ON on mb_free_blocks(): BUG_ON(last >= (sb->s_blocksize << 3)); Fix this by bailing out of ext4_discard_allocated_blocks() if fs_len is zero. Also fix a missing ext4_mb_unload_buddy() call in ext4_discard_allocated_blocks(). Google-Bug-Id: 16844242 Fixes: 86f0afd463215fc3e58020493482faa4ac3a4d69 Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org

ext4: fix ext4_discard_allocated_blocks() if we can't allocate the pa struct

2014-07-31T02:17:17Z

If there is a failure while allocating the preallocation structure, a number of blocks can end up getting marked in the in-memory buddy bitmap, and then not getting released. This can result in the following corruption getting reported by the kernel: EXT4-fs error (device sda3): ext4_mb_generate_buddy:758: group 1126, 12793 clusters in bitmap, 12729 in gd In that case, we need to release the blocks using mb_free_blocks(). Tested: fs smoke test; also demonstrated that with injected errors, the file system is no longer getting corrupted Google-Bug-Id: 16657874 Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org

ext4: fix wrong size computation in ext4_mb_normalize_request()

2014-07-28T02:26:36Z

As the member fe_len defined in struct ext4_free_extent is expressed as number of clusters, the variable "size" computation is wrong, we need to first translate fe_len to block number, then to bytes. Signed-off-by: Xiaoguang Wang Signed-off-by: Theodore Ts'o Reviewed-by: Lukas Czerner

ext4: remove metadata reservation checks

2014-07-15T10:02:38Z

Commit 27dd43854227b ("ext4: introduce reserved space") reserves 2% of the file system space to make sure metadata allocations will always succeed. Given that, tracking the reservation of metadata blocks is no longer necessary. Signed-off-by: Theodore Ts'o

ext4: clarify ext4_error message in ext4_mb_generate_buddy_error()

2014-07-05T23:15:50Z

We are spending a lot of time explaining to users what this error means. Let's try to improve the message to avoid this problem. Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org

ext4: decrement free clusters/inodes counters when block group declared bad

2014-06-26T14:11:53Z

We should decrement free clusters counter when block bitmap is marked as corrupt and free inodes counter when the allocation bitmap is marked as corrupt to avoid misunderstanding due to incorrect available size in statfs result. User can get immediately ENOSPC error from write begin without reaching for the writepages. Cc: Darrick J. Wong Reported-by: Amit Sahrawat Signed-off-by: Namjae Jeon Signed-off-by: Ashish Sangwan

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2014-06-08T20:03:35Z

Pull ext4 updates from Ted Ts'o: "Clean ups and miscellaneous bug fixes, in particular for the new collapse_range and zero_range fallocate functions. In addition, improve the scalability of adding and remove inodes from the orphan list" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits) ext4: handle symlink properly with inline_data ext4: fix wrong assert in ext4_mb_normalize_request() ext4: fix zeroing of page during writeback ext4: remove unused local variable "stored" from ext4_readdir(...) ext4: fix ZERO_RANGE test failure in data journalling ext4: reduce contention on s_orphan_lock ext4: use sbi in ext4_orphan_{add|del}() ext4: use EXT_MAX_BLOCKS in ext4_es_can_be_merged() ext4: add missing BUFFER_TRACE before ext4_journal_get_write_access ext4: remove unnecessary double parentheses ext4: do not destroy ext4_groupinfo_caches if ext4_mb_init() fails ext4: make local functions static ext4: fix block bitmap validation when bigalloc, ^flex_bg ext4: fix block bitmap initialization under sparse_super2 ext4: find the group descriptors on a 1k-block bigalloc,meta_bg filesystem ext4: avoid unneeded lookup when xattr name is invalid ext4: fix data integrity sync in ordered mode ext4: remove obsoleted check ext4: add a new spinlock i_raw_lock to protect the ext4's raw inode ext4: fix locking for O_APPEND writes ...

mm: non-atomically mark page accessed during page cache allocation where possible

2014-06-04T23:54:10Z

aops->write_begin may allocate a new page and make it visible only to have mark_page_accessed called almost immediately after. Once the page is visible the atomic operations are necessary which is noticable overhead when writing to an in-memory filesystem like tmpfs but should also be noticable with fast storage. The objective of the patch is to initialse the accessed information with non-atomic operations before the page is visible. The bulk of filesystems directly or indirectly use grab_cache_page_write_begin or find_or_create_page for the initial allocation of a page cache page. This patch adds an init_page_accessed() helper which behaves like the first call to mark_page_accessed() but may called before the page is visible and can be done non-atomically. The primary APIs of concern in this care are the following and are used by most filesystems. find_get_page find_lock_page find_or_create_page grab_cache_page_nowait grab_cache_page_write_begin All of them are very similar in detail to the patch creates a core helper pagecache_get_page() which takes a flags parameter that affects its behavior such as whether the page should be marked accessed or not. Then old API is preserved but is basically a thin wrapper around this core function. Each of the filesystems are then updated to avoid calling mark_page_accessed when it is known that the VM interfaces have already done the job. There is a slight snag in that the timing of the mark_page_accessed() has now changed so in rare cases it's possible a page gets to the end of the LRU as PageReferenced where as previously it might have been repromoted. This is expected to be rare but it's worth the filesystem people thinking about it in case they see a problem with the timing change. It is also the case that some filesystems may be marking pages accessed that previously did not but it makes sense that filesystems have consistent behaviour in this regard. The test case used to evaulate this is a simple dd of a large file done multiple times with the file deleted on each iterations. The size of the file is 1/10th physical memory to avoid dirty page balancing. In the async case it will be possible that the workload completes without even hitting the disk and will have variable results but highlight the impact of mark_page_accessed for async IO. The sync results are expected to be more stable. The exception is tmpfs where the normal case is for the "IO" to not hit the disk. The test machine was single socket and UMA to avoid any scheduling or NUMA artifacts. Throughput and wall times are presented for sync IO, only wall times are shown for async as the granularity reported by dd and the variability is unsuitable for comparison. As async results were variable do to writback timings, I'm only reporting the maximum figures. The sync results were stable enough to make the mean and stddev uninteresting. The performance results are reported based on a run with no profiling. Profile data is based on a separate run with oprofile running. async dd 3.15.0-rc3 3.15.0-rc3 vanilla accessed-v2 ext3 Max elapsed 13.9900 ( 0.00%) 11.5900 ( 17.16%) tmpfs Max elapsed 0.5100 ( 0.00%) 0.4900 ( 3.92%) btrfs Max elapsed 12.8100 ( 0.00%) 12.7800 ( 0.23%) ext4 Max elapsed 18.6000 ( 0.00%) 13.3400 ( 28.28%) xfs Max elapsed 12.5600 ( 0.00%) 2.0900 ( 83.36%) The XFS figure is a bit strange as it managed to avoid a worst case by sheer luck but the average figures looked reasonable. samples percentage ext3 86107 0.9783 vmlinux-3.15.0-rc4-vanilla mark_page_accessed ext3 23833 0.2710 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed ext3 5036 0.0573 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed ext4 64566 0.8961 vmlinux-3.15.0-rc4-vanilla mark_page_accessed ext4 5322 0.0713 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed ext4 2869 0.0384 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed xfs 62126 1.7675 vmlinux-3.15.0-rc4-vanilla mark_page_accessed xfs 1904 0.0554 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed xfs 103 0.0030 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed btrfs 10655 0.1338 vmlinux-3.15.0-rc4-vanilla mark_page_accessed btrfs 2020 0.0273 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed btrfs 587 0.0079 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed tmpfs 59562 3.2628 vmlinux-3.15.0-rc4-vanilla mark_page_accessed tmpfs 1210 0.0696 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed tmpfs 94 0.0054 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed [akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer] Signed-off-by: Mel Gorman Cc: Johannes Weiner Cc: Vlastimil Babka Cc: Jan Kara Cc: Michal Hocko Cc: Hugh Dickins Cc: Dave Hansen Cc: Theodore Ts'o Cc: "Paul E. McKenney" Cc: Oleg Nesterov Cc: Rik van Riel Cc: Peter Zijlstra Tested-by: Prabhakar Lad Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ext4: fix wrong assert in ext4_mb_normalize_request()

2014-05-27T16:48:56Z

The variable "size" is expressed as number of blocks and not as number of clusters, this could trigger a kernel panic when using ext4 with the size of a cluster different from the size of a block. Cc: stable@vger.kernel.org Signed-off-by: Maurizio Lombardi Signed-off-by: Theodore Ts'o

ext4: add missing BUFFER_TRACE before ext4_journal_get_write_access

2014-05-13T02:06:43Z

Make them more consistently Signed-off-by: xieliang Signed-off-by: "Theodore Ts'o"