kernel.git/fs/nilfs2/inode.c, branch linux-3.17.y

nilfs2: fix data loss with mmap()

2014-09-26T15:10:34Z

This bug leads to reproducible silent data loss, despite the use of msync(), sync() and a clean unmount of the file system. It is easily reproducible with the following script: ----------------[BEGIN SCRIPT]-------------------- mkfs.nilfs2 -f /dev/sdb mount /dev/sdb /mnt dd if=/dev/zero bs=1M count=30 of=/mnt/testfile umount /mnt mount /dev/sdb /mnt CHECKSUM_BEFORE="$(md5sum /mnt/testfile)" /root/mmaptest/mmaptest /mnt/testfile 30 10 5 sync CHECKSUM_AFTER="$(md5sum /mnt/testfile)" umount /mnt mount /dev/sdb /mnt CHECKSUM_AFTER_REMOUNT="$(md5sum /mnt/testfile)" umount /mnt echo "BEFORE MMAP:\t$CHECKSUM_BEFORE" echo "AFTER MMAP:\t$CHECKSUM_AFTER" echo "AFTER REMOUNT:\t$CHECKSUM_AFTER_REMOUNT" ----------------[END SCRIPT]-------------------- The mmaptest tool looks something like this (very simplified, with error checking removed): ----------------[BEGIN mmaptest]-------------------- data = mmap(NULL, file_size - file_offset, PROT_READ | PROT_WRITE, MAP_SHARED, fd, file_offset); for (i = 0; i < write_count; ++i) { memcpy(data + i * 4096, buf, sizeof(buf)); msync(data, file_size - file_offset, MS_SYNC)) } ----------------[END mmaptest]-------------------- The output of the script looks something like this: BEFORE MMAP: 281ed1d5ae50e8419f9b978aab16de83 /mnt/testfile AFTER MMAP: 6604a1c31f10780331a6850371b3a313 /mnt/testfile AFTER REMOUNT: 281ed1d5ae50e8419f9b978aab16de83 /mnt/testfile So it is clear, that the changes done using mmap() do not survive a remount. This can be reproduced a 100% of the time. The problem was introduced in commit 136e8770cd5d ("nilfs2: fix issue of nilfs_set_page_dirty() for page at EOF boundary"). If the page was read with mpage_readpage() or mpage_readpages() for example, then it has no buffers attached to it. In that case page_has_buffers(page) in nilfs_set_page_dirty() will be false. Therefore nilfs_set_file_dirty() is never called and the pages are never collected and never written to disk. This patch fixes the problem by also calling nilfs_set_file_dirty() if the page has no buffers attached to it. [akpm@linux-foundation.org: s/PAGE_SHIFT/PAGE_CACHE_SHIFT/] Signed-off-by: Andreas Rohner Tested-by: Andreas Rohner Signed-off-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

switch {__,}blockdev_direct_IO() to iov_iter

2014-05-06T21:32:46Z

Signed-off-by: Al Viro

get rid of pointless iov_length() in ->direct_IO()

2014-05-06T21:32:45Z

all callers have iov_length(iter->iov, iter->nr_segs) == iov_iter_count(iter) Signed-off-by: Al Viro

pass iov_iter to ->direct_IO()

2014-05-06T21:32:44Z

unmodified, for now Signed-off-by: Al Viro

mm + fs: store shadow entries in page cache

2014-04-03T23:21:01Z

Reclaim will be leaving shadow entries in the page cache radix tree upon evicting the real page. As those pages are found from the LRU, an iput() can lead to the inode being freed concurrently. At this point, reclaim must no longer install shadow pages because the inode freeing code needs to ensure the page tree is really empty. Add an address_space flag, AS_EXITING, that the inode freeing code sets under the tree lock before doing the final truncate. Reclaim will check for this flag before installing shadow pages. Signed-off-by: Johannes Weiner Reviewed-by: Rik van Riel Reviewed-by: Minchan Kim Cc: Andrea Arcangeli Cc: Bob Liu Cc: Christoph Hellwig Cc: Dave Chinner Cc: Greg Thelen Cc: Hugh Dickins Cc: Jan Kara Cc: KOSAKI Motohiro Cc: Luigi Semenzato Cc: Mel Gorman Cc: Metin Doslu Cc: Michel Lespinasse Cc: Ozgun Erdogan Cc: Peter Zijlstra Cc: Roman Gushchin Cc: Ryan Mallon Cc: Tejun Heo Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

truncate: drop 'oldsize' truncate_pagecache() parameter

2013-09-12T22:38:02Z

truncate_pagecache() doesn't care about old size since commit cedabed49b39 ("vfs: Fix vmtruncate() regression"). Let's drop it. Signed-off-by: Kirill A. Shutemov Cc: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

] nilfs2: use atomic64_t type for inodes_count and blocks_count fields in nilfs_root struct

2013-07-03T23:08:01Z

The cp_inodes_count and cp_blocks_count are represented as __le64 type in on-disk structure (struct nilfs_checkpoint). But analogous fields in in-core structure (struct nilfs_root) are represented by atomic_t type. This patch replaces atomic_t on atomic64_t type in representation of inodes_count and blocks_count fields in struct nilfs_root. Signed-off-by: Vyacheslav Dubeyko Acked-by: Ryusuke Konishi Acked-by: Joern Engel Cc: Clemens Eisserer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: fix issue of nilfs_set_page_dirty() for page at EOF boundary

2013-05-24T23:22:52Z

nilfs2: fix issue of nilfs_set_page_dirty for page at EOF boundary DESCRIPTION: There are use-cases when NILFS2 file system (formatted with block size lesser than 4 KB) can be remounted in RO mode because of encountering of "broken bmap" issue. The issue was reported by Anthony Doggett : "The machine I've been trialling nilfs on is running Debian Testing, Linux version 3.2.0-4-686-pae (debian-kernel@lists.debian.org) (gcc version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Debian 3.2.35-2), but I've also reproduced it (identically) with Debian Unstable amd64 and Debian Experimental (using the 3.8-trunk kernel). The problematic partitions were formatted with "mkfs.nilfs2 -b 1024 -B 8192"." SYMPTOMS: (1) System log contains error messages likewise: [63102.496756] nilfs_direct_assign: invalid pointer: 0 [63102.496786] NILFS error (device dm-17): nilfs_bmap_assign: broken bmap (inode number=28) [63102.496798] [63102.524403] Remounting filesystem read-only (2) The NILFS2 file system is remounted in RO mode. REPRODUSING PATH: (1) Create volume group with name "unencrypted" by means of vgcreate utility. (2) Run script (prepared by Anthony Doggett ): ----------------[BEGIN SCRIPT]-------------------- VG=unencrypted lvcreate --size 2G --name ntest $VG mkfs.nilfs2 -b 1024 -B 8192 /dev/mapper/$VG-ntest mkdir /var/tmp/n mkdir /var/tmp/n/ntest mount /dev/mapper/$VG-ntest /var/tmp/n/ntest mkdir /var/tmp/n/ntest/thedir cd /var/tmp/n/ntest/thedir sleep 2 date darcs init sleep 2 dmesg|tail -n 5 date darcs whatsnew || true date sleep 2 dmesg|tail -n 5 ----------------[END SCRIPT]-------------------- REPRODUCIBILITY: 100% INVESTIGATION: As it was discovered, the issue takes place during segment construction after executing such sequence of user-space operations: open("_darcs/index", O_RDWR|O_CREAT|O_NOCTTY, 0666) = 7 fstat(7, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0 ftruncate(7, 60) The error message "NILFS error (device dm-17): nilfs_bmap_assign: broken bmap (inode number=28)" takes place because of trying to get block number for third block of the file with logical offset #3072 bytes. As it is possible to see from above output, the file has 60 bytes of the whole size. So, it is enough one block (1 KB in size) allocation for the whole file. Trying to operate with several blocks instead of one takes place because of discovering several dirty buffers for this file in nilfs_segctor_scan_file() method. The root cause of this issue is in nilfs_set_page_dirty function which is called just before writing to an mmapped page. When nilfs_page_mkwrite function handles a page at EOF boundary, it fills hole blocks only inside EOF through __block_page_mkwrite(). The __block_page_mkwrite() function calls set_page_dirty() after filling hole blocks, thus nilfs_set_page_dirty function (= a_ops->set_page_dirty) is called. However, the current implementation of nilfs_set_page_dirty() wrongly marks all buffers dirty even for page at EOF boundary. As a result, buffers outside EOF are inconsistently marked dirty and queued for write even though they are not mapped with nilfs_get_block function. FIX: This modifies nilfs_set_page_dirty() not to mark hole blocks dirty. Thanks to Vyacheslav Dubeyko for his effort on analysis and proposals for this issue. Signed-off-by: Ryusuke Konishi Reported-by: Anthony Doggett Reported-by: Vyacheslav Dubeyko Cc: Vyacheslav Dubeyko Tested-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

aio: don't include aio.h in sched.h

2013-05-08T03:16:25Z

Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet Cc: Zach Brown Cc: Felipe Balbi Cc: Greg Kroah-Hartman Cc: Mark Fasheh Cc: Joel Becker Cc: Rusty Russell Cc: Jens Axboe Cc: Asai Thambi S P Cc: Selvan Mani Cc: Sam Bradshaw Cc: Jeff Moyer Cc: Al Viro Cc: Benjamin LaHaise Reviewed-by: "Theodore Ts'o" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: remove unneeded test in nilfs_writepage()

2013-05-01T00:04:05Z

page->mapping->host cannot be NULL in nilfs_writepage(), so remove the unneeded test. The fixes the smatch warning: "fs/nilfs2/inode.c:211 nilfs_writepage() error: we previously assumed 'inode' could be null (see line 195)". Reported-by: Dan Carpenter Signed-off-by: Vyacheslav Dubeyko Cc: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds