linux/fs/buffer.c, branch v4.1

page_writeback: clean up mess around cancel_dirty_page()

2015-04-14T23:49:01Z

This patch replaces cancel_dirty_page() with a helper function account_page_cleaned() which only updates counters. It's called from truncate_complete_page() and from try_to_free_buffers() (hack for ext3). Page is locked in both cases, page-lock protects against concurrent dirtiers: see commit 2d6d7f982846 ("mm: protect set_page_dirty() from ongoing truncation"). Delete_from_page_cache() shouldn't be called for dirty pages, they must be handled by caller (either written or truncated). This patch treats final dirty accounting fixup at the end of __delete_from_page_cache() as a debug check and adds WARN_ON_ONCE() around it. If something removes dirty pages without proper handling that might be a bug and unwritten data might be lost. Hugetlbfs has no dirty pages accounting, ClearPageDirty() is enough here. cancel_dirty_page() in nfs_wb_page_cancel() is redundant. This is helper for nfs_invalidate_page() and it's called only in case complete invalidation. The mess was started in v2.6.20 after commits 46d2277c796f ("Clean up and make try_to_free_buffers() not race with dirty pages") and 3e67c0987d75 ("truncate: clear page dirtiness before running try_to_free_buffers()") first was reverted right in v2.6.20 in commit ecdfc9787fe5 ("Resurrect 'try_to_free_buffers()' VM hackery"), second in v2.6.25 commit a2b345642f53 ("Fix dirty page accounting leak with ext3 data=journal"). Custom fixes were introduced between these points. NFS in v2.6.23, commit 1b3b4a1a2deb ("NFS: Fix a write request leak in nfs_invalidate_page()"). Kludge in __delete_from_page_cache() in v2.6.24, commit 3a6927906f1b ("Do dirty page accounting when removing a page from the page cache"). Since v2.6.25 all of them are redundant. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Konstantin Khlebnikov Cc: Tejun Heo Cc: Jan Kara Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: clarify rate limit suppressed buffer I/O errors

2014-10-21T19:55:11Z

When quiet_error applies rate limiting to buffer_io_error calls, what the they apply to is unclear because the name is so generic, particularly if the messages are interleaved with others: [ 1936.063572] quiet_error: 664293 callbacks suppressed [ 1936.065297] Buffer I/O error on dev sdr, logical block 257429952, lost async page write [ 1936.067814] Buffer I/O error on dev sdr, logical block 257429953, lost async page write Also, the function uses printk_ratelimit(), although printk.h includes a comment advising "Please don't use... Instead use printk_ratelimited()." Change buffer_io_error to check the BH_Quiet bit itself, drop the printk_ratelimit call, and print using printk_ratelimited. This makes the messages look like: [ 387.208839] buffer_io_error: 676394 callbacks suppressed [ 387.210693] Buffer I/O error on dev sdr, logical block 211291776, lost async page write [ 387.213432] Buffer I/O error on dev sdr, logical block 211291777, lost async page write Signed-off-by: Robert Elliott Reviewed-by: Webb Scales Signed-off-by: Jens Axboe

fs: merge I/O error prints into one line

2014-10-21T19:55:09Z

buffer.c uses two printk calls to print these messages: [67353.422338] Buffer I/O error on device sdr, logical block 212868488 [67353.422338] lost page write due to I/O error on sdr In a busy system, they may be interleaved with other prints, losing the context for the second message. Merge them into one line with one printk call so the prints are atomic. Also, differentiate between async page writes, sync page writes, and async page reads. Also, shorten "device" to "dev" to match the block layer prints: [67353.467906] blk_update_request: critical target error, dev sdr, sector 1707107328 Also, use %llu rather than %Lu. Resulting prints look like: [ 1356.437006] blk_update_request: critical target error, dev sdr, sector 1719693992 [ 1361.383522] quiet_error: 659876 callbacks suppressed [ 1361.385816] Buffer I/O error on dev sdr, logical block 256902912, lost async page write [ 1361.385819] Buffer I/O error on dev sdr, logical block 256903644, lost async page write Signed-off-by: Robert Elliott Reviewed-by: Webb Scales Signed-off-by: Jens Axboe

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

2014-10-20T16:50:11Z

Pull ext4 updates from Ted Ts'o: "A large number of cleanups and bug fixes, with some (minor) journal optimizations" [ This got sent to me before -rc1, but was stuck in my spam folder. - Linus ] * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (67 commits) ext4: check s_chksum_driver when looking for bg csum presence ext4: move error report out of atomic context in ext4_init_block_bitmap() ext4: Replace open coded mdata csum feature to helper function ext4: delete useless comments about ext4_move_extents ext4: fix reservation overflow in ext4_da_write_begin ext4: add ext4_iget_normal() which is to be used for dir tree lookups ext4: don't orphan or truncate the boot loader inode ext4: grab missed write_count for EXT4_IOC_SWAP_BOOT ext4: optimize block allocation on grow indepth ext4: get rid of code duplication ext4: fix over-defensive complaint after journal abort ext4: fix return value of ext4_do_update_inode ext4: fix mmap data corruption when blocksize < pagesize vfs: fix data corruption when blocksize < pagesize for mmaped data ext4: fold ext4_nojournal_sops into ext4_sops ext4: support freezing ext2 (nojournal) file systems ext4: fold ext4_sync_fs_nojournal() into ext4_sync_fs() ext4: don't check quota format when there are no quota files jbd2: simplify calling convention around __jbd2_journal_clean_checkpoint_list jbd2: avoid pointless scanning of checkpoint lists ...

fs: check bh blocknr earlier when searching lru

2014-10-14T00:18:26Z

It's very common for the buffer heads in the lru to have different block numbers. By comparing the blocknr before the bdev and size we can reduce the cost of searching in the very common case where all the entries have the same bdev and size. In quick hot cache cycle counting tests on a single fs workstation this cut the cost of a miss by about 20%. A diff of the disassembly shows the reordering of the bdev and blocknr comparisons. This is in such a tiny loop that skipping one comparison is a meaningful portion of the total work being done: 1628: 83 c1 01 add $0x1,%ecx 162b: 83 f9 08 cmp $0x8,%ecx 162e: 74 60 je 1690 <__find_get_block+0xa0> 1630: 89 c8 mov %ecx,%eax 1632: 65 4c 8b 04 c5 00 00 mov %gs:0x0(,%rax,8),%r8 1639: 00 00 163b: 4d 85 c0 test %r8,%r8 163e: 4c 89 c3 mov %r8,%rbx 1641: 74 e5 je 1628 <__find_get_block+0x38> - 1643: 4d 3b 68 30 cmp 0x30(%r8),%r13 + 1643: 4d 3b 68 18 cmp 0x18(%r8),%r13 1647: 75 df jne 1628 <__find_get_block+0x38> - 1649: 4d 3b 60 18 cmp 0x18(%r8),%r12 + 1649: 4d 3b 60 30 cmp 0x30(%r8),%r12 164d: 75 d9 jne 1628 <__find_get_block+0x38> 164f: 49 39 50 20 cmp %rdx,0x20(%r8) 1653: 75 d3 jne 1628 <__find_get_block+0x38> Signed-off-by: Zach Brown Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2014-10-13T09:28:42Z

Pull vfs updates from Al Viro: "The big thing in this pile is Eric's unmount-on-rmdir series; we finally have everything we need for that. The final piece of prereqs is delayed mntput() - now filesystem shutdown always happens on shallow stack. Other than that, we have several new primitives for iov_iter (Matt Wilcox, culled from his XIP-related series) pushing the conversion to ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c cleanups and fixes (including the external name refcounting, which gives consistent behaviour of d_move() wrt procfs symlinks for long and short names alike) and assorted cleanups and fixes all over the place. This is just the first pile; there's a lot of stuff from various people that ought to go in this window. Starting with unionmount/overlayfs mess... ;-/" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits) fs/file_table.c: Update alloc_file() comment vfs: Deduplicate code shared by xattr system calls operating on paths reiserfs: remove pointless forward declaration of struct nameidata don't need that forward declaration of struct nameidata in dcache.h anymore take dname_external() into fs/dcache.c let path_init() failures treated the same way as subsequent link_path_walk() fix misuses of f_count() in ppp and netlink ncpfs: use list_for_each_entry() for d_subdirs walk vfs: move getname() from callers to do_mount() gfs2_atomic_open(): skip lookups on hashed dentry [infiniband] remove pointless assignments gadgetfs: saner API for gadgetfs_create_file() f_fs: saner API for ffs_sb_create_file() jfs: don't hash direct inode [s390] remove pointless assignment of ->f_op in vmlogrdr ->open() ecryptfs: ->f_op is never NULL android: ->f_op is never NULL nouveau: __iomem misannotations missing annotation in fs/file.c fs: namespace: suppress 'may be used uninitialized' warnings ...

fs/buffer.c: increase the buffer-head per-CPU LRU size

2014-10-10T02:26:02Z

Increase the buffer-head per-CPU LRU size to allow efficient filesystem operations that access many blocks for each transaction. For example, creating a file in a large ext4 directory with quota enabled will access multiple buffer heads and will overflow the LRU at the default 8-block LRU size: * parent directory inode table block (ctime, nlinks for subdirs) * new inode bitmap * inode table block * 2 quota blocks * directory leaf block (not reused, but pollutes one cache entry) * 2 levels htree blocks (only one is reused, other pollutes cache) * 2 levels indirect/index blocks (only one is reused) The buffer-head per-CPU LRU size is raised to 16, as it shows in metadata performance benchmarks up to 10% gain for create, 4% for lookup and 7% for destroy. Signed-off-by: Liang Zhen Signed-off-by: Andreas Dilger Signed-off-by: Sebastien Buisson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vfs: guard end of device for mpage interface

2014-10-10T02:25:53Z

Add guard_bio_eod() check for mpage code in order to allow us to do IO even on the odd last sectors of a device, even if the block size is some multiple of the physical sector size. Using mpage_readpages() for block device requires this guard check. Signed-off-by: Akinobu Mita Cc: Jens Axboe Cc: Alexander Viro Cc: Jeff Moyer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

vfs: make guard_bh_eod() more generic

2014-10-10T02:25:53Z

This patchset implements readpages() operation for block device by using mpage_readpages() which can create multipage BIOs instead of BIOs for each page and reduce system CPU time consumption. This patch (of 3): guard_bh_eod() is used in submit_bh() to allow us to do IO even on the odd last sectors of a device, even if the block size is some multiple of the physical sector size. This makes guard_bh_eod() more generic and renames it guard_bio_eod() so that we can use it without struct buffer_head argument. The reason for this change is that using mpage_readpages() for block device requires to add this guard check in mpage code. Signed-off-by: Akinobu Mita Cc: Jens Axboe Cc: Alexander Viro Cc: Jeff Moyer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs: make cont_expand_zero interruptible

2014-10-09T06:39:03Z

This patch makes it possible to kill a process looping in cont_expand_zero. A process may spend a lot of time in this function, so it is desirable to be able to kill it. It happened to me that I wanted to copy a piece data from the disk to a file. By mistake, I used the "seek" parameter to dd instead of "skip". Due to the "seek" parameter, dd attempted to extend the file and became stuck doing so - the only possibility was to reset the machine or wait many hours until the filesystem runs out of space and cont_expand_zero fails. We need this patch to be able to terminate the process. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Al Viro