linux-toradex.git/fs/nilfs2, branch v4.4.110

nilfs2: fix race condition that causes file system corruption

2017-11-30T08:37:20+00:00

commit 31ccb1f7ba3cfe29631587d451cf5bb8ab593550 upstream.

There is a race condition between nilfs_dirty_inode() and
nilfs_set_file_dirty().

When a file is opened, nilfs_dirty_inode() is called to update the
access timestamp in the inode. It calls __nilfs_mark_inode_dirty() in a
separate transaction. __nilfs_mark_inode_dirty() caches the ifile
buffer_head in the i_bh field of the inode info structure and marks it
as dirty.

After some data was written to the file in another transaction, the
function nilfs_set_file_dirty() is called, which adds the inode to the
ns_dirty_files list.

Then the segment construction calls nilfs_segctor_collect_dirty_files(),
which goes through the ns_dirty_files list and checks the i_bh field.
If there is a cached buffer_head in i_bh it is not marked as dirty
again.

Since nilfs_dirty_inode() and nilfs_set_file_dirty() use separate
transactions, it is possible that a segment construction that writes out
the ifile occurs in-between the two. If this happens the inode is not
on the ns_dirty_files list, but its ifile block is still marked as dirty
and written out.

In the next segment construction, the data for the file is written out
and nilfs_bmap_propagate() updates the b-tree. Eventually the bmap root
is written into the i_bh block, which is not dirty, because it was
written out in another segment construction.

As a result the bmap update can be lost, which leads to file system
corruption. Either the virtual block address points to an unallocated
DAT block, or the DAT entry will be reused for something different.

The error can remain undetected for a long time. A typical error
message would be one of the "bad btree" errors or a warning that a DAT
entry could not be found.

This bug can be reproduced reliably by a simple benchmark that creates
and overwrites millions of 4k files.

Link: http://lkml.kernel.org/r/1509367935-3086-2-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Andreas Rohner
Signed-off-by: Ryusuke Konishi
Tested-by: Andreas Rohner
Tested-by: Ryusuke Konishi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Greg Kroah-Hartman

fs: add i_blocksize()

2017-06-14T11:16:24+00:00

commit 93407472a21b82f39c955ea7787e5bc7da100642 upstream.

Replace all 1 << inode->i_blkbits and (1 << inode->i_blkbits) in fs
branch.

This patch also fixes multiple checkpatch warnings: WARNING: Prefer
'unsigned int' to bare use of 'unsigned'

Thanks to Andrew Morton for suggesting more appropriate function instead
of macro.

[geliangtang@gmail.com: truncate: use i_blocksize()]
  Link: http://lkml.kernel.org/r/9c8b2cd83c8f5653805d43debde9fa8817e02fc4.1484895804.git.geliangtang@gmail.com
Link: http://lkml.kernel.org/r/1481319905-10126-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick 
Signed-off-by: Geliang Tang 
Cc: Alexander Viro 
Cc: Ross Zwisler 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fs/nilfs2: fix potential underflow in call to crc32_le

2016-08-10T09:49:25+00:00

commit 63d2f95d63396059200c391ca87161897b99e74a upstream.

The value `bytes' comes from the filesystem which is about to be
mounted.  We cannot trust that the value is always in the range we
expect it to be.

Check its value before using it to calculate the length for the crc32_le
call.  It value must be larger (or equal) sumoff + 4.

This fixes a kernel bug when accidentially mounting an image file which
had the nilfs2 magic value 0x3434 at the right offset 0x406 by chance.
The bytes 0x01 0x00 were stored at 0x408 and were interpreted as a
s_bytes value of 1.  This caused an underflow when substracting sumoff +
4 (20) in the call to crc32_le.

  BUG: unable to handle kernel paging request at ffff88021e600000
  IP:  crc32_le+0x36/0x100
  ...
  Call Trace:
    nilfs_valid_sb.part.5+0x52/0x60 [nilfs2]
    nilfs_load_super_block+0x142/0x300 [nilfs2]
    init_nilfs+0x60/0x390 [nilfs2]
    nilfs_mount+0x302/0x520 [nilfs2]
    mount_fs+0x38/0x160
    vfs_kern_mount+0x67/0x110
    do_mount+0x269/0xe00
    SyS_mount+0x9f/0x100
    entry_SYSCALL_64_fastpath+0x16/0x71

Link: http://lkml.kernel.org/r/1466778587-5184-2-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Torsten Hilbrich 
Tested-by: Torsten Hilbrich 
Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2015-11-11T17:45:24+00:00

Pull vfs update from Al Viro:

 - misc stable fixes

 - trivial kernel-doc and comment fixups

 - remove never-used block_page_mkwrite() wrapper function, and rename
   the function that is _actually_ used to not have double underscores.

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: 9p: cache.h: Add #define of include guard
  vfs: remove stale comment in inode_operations
  vfs: remove unused wrapper block_page_mkwrite()
  binfmt_elf: Correct `arch_check_elf's description
  fs: fix writeback.c kernel-doc warnings
  fs: fix inode.c kernel-doc warning
  fs/pipe.c: return error code rather than 0 in pipe_write()
  fs/pipe.c: preserve alloc_file() error code
  binfmt_elf: Don't clobber passed executable's file header
  FS-Cache: Handle a write to the page immediately beyond the EOF marker
  cachefiles: perform test on s_blocksize when opening cache file.
  FS-Cache: Don't override netfs's primary_index if registering failed
  FS-Cache: Increase reference of parent after registering, netfs success
  debugfs: fix refcount imbalance in start_creating

vfs: remove unused wrapper block_page_mkwrite()

2015-11-11T07:19:33+00:00

The function currently called "__block_page_mkwrite()" used to be called
"block_page_mkwrite()" until a wrapper for this function was added by:

commit 24da4fab5a61 ("vfs: Create __block_page_mkwrite() helper passing
	error values back")

This wrapper, the current "block_page_mkwrite()", is currently unused.
__block_page_mkwrite() is used directly by ext4, nilfs2 and xfs.

Remove the unused wrapper, rename __block_page_mkwrite() back to
block_page_mkwrite() and update the comment above block_page_mkwrite().

Signed-off-by: Ross Zwisler 
Reviewed-by: Jan Kara 
Cc: Jan Kara 
Cc: Christoph Hellwig 
Cc: Al Viro 
Signed-off-by: Al Viro

fs/nilfs2/namei.c: remove unnecessary new_valid_dev() check

2015-11-09T23:11:24+00:00

new_valid_dev() always returns 1, so the !new_valid_dev() check is not
needed.  Remove it.

Signed-off-by: Yaowei Bai 
Cc: Alexander Viro 
Acked-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nilfs2: fix gcc uninitialized-variable warnings in powerpc build

2015-11-07T01:50:42+00:00

Some false positive warnings are reported for powerpc build.

The following warnings are reported in
 http://kisskb.ellerman.id.au/kisskb/buildresult/12519703/

   CC      fs/nilfs2/super.o
 fs/nilfs2/super.c: In function 'nilfs_resize_fs':
 fs/nilfs2/super.c:376:2: warning: 'blocknr' may be used uninitialized in this function [-Wuninitialized]
 fs/nilfs2/super.c:362:11: note: 'blocknr' was declared here
   CC      fs/nilfs2/recovery.o
 fs/nilfs2/recovery.c: In function 'nilfs_salvage_orphan_logs':
 fs/nilfs2/recovery.c:631:21: warning: 'sum' may be used uninitialized in this function [-Wuninitialized]
 fs/nilfs2/recovery.c:585:32: note: 'sum' was declared here
 fs/nilfs2/recovery.c: In function 'nilfs_search_super_root':
 fs/nilfs2/recovery.c:873:11: warning: 'sum' may be used uninitialized in this function [-Wuninitialized]

Another similar warning is reported in
 http://kisskb.ellerman.id.au/kisskb/buildresult/12520079/

   CC      fs/nilfs2/btree.o
 fs/nilfs2/btree.c: In function 'nilfs_btree_convert_and_insert':
 include/asm-generic/bitops/non-atomic.h:105:20: warning: 'bh' may be used uninitialized in this function [-Wuninitialized]
 fs/nilfs2/btree.c:1859:22: note: 'bh' was declared here

This cleans out these warnings by forcing the variables to be initialized.

Signed-off-by: Ryusuke Konishi 
Reported-by: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nilfs2: fix gcc unused-but-set-variable warnings

2015-11-07T01:50:42+00:00

Fix the following build warnings:

 $ make W=1
 [...]
   CC [M]  fs/nilfs2/btree.o
 fs/nilfs2/btree.c: In function 'nilfs_btree_split':
 fs/nilfs2/btree.c:923:8: warning: variable 'newptr' set but not used [-Wunused-but-set-variable]
   __u64 newptr;
         ^
 fs/nilfs2/btree.c:922:8: warning: variable 'newkey' set but not used [-Wunused-but-set-variable]
   __u64 newkey;
         ^
   CC [M]  fs/nilfs2/dat.o
 fs/nilfs2/dat.c: In function 'nilfs_dat_prepare_end':
 fs/nilfs2/dat.c:158:8: warning: variable 'start' set but not used [-Wunused-but-set-variable]
   __u64 start;
         ^
   CC [M]  fs/nilfs2/segment.o
 fs/nilfs2/segment.c: In function 'nilfs_segctor_do_immediate_flush':
 fs/nilfs2/segment.c:2433:6: warning: variable 'err' set but not used [-Wunused-but-set-variable]
   int err;
       ^
   CC [M]  fs/nilfs2/sufile.o
 fs/nilfs2/sufile.c: In function 'nilfs_sufile_alloc':
 fs/nilfs2/sufile.c:320:27: warning: variable 'ncleansegs' set but not used [-Wunused-but-set-variable]
   unsigned long nsegments, ncleansegs, nsus, cnt;
                            ^
   CC [M]  fs/nilfs2/alloc.o
 fs/nilfs2/alloc.c: In function 'nilfs_palloc_prepare_alloc_entry':
 fs/nilfs2/alloc.c:478:38: warning: variable 'groups_per_desc_block' set but not used [-Wunused-but-set-variable]
   unsigned long n, entries_per_group, groups_per_desc_block;
                                       ^

Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nilfs2: add tracepoints for analyzing reading and writing metadata files

2015-11-07T01:50:42+00:00

This patch adds tracepoints for analyzing requests of reading and writing
metadata files.  The tracepoints cover every in-place mdt files (cpfile,
sufile, and datfile).

Example of tracing mdt_insert_new_block():
              cp-14635 [000] ...1 30598.199309: nilfs2_mdt_insert_new_block: inode = ffff88022a8d0178 ino = 3 block = 155
              cp-14635 [000] ...1 30598.199520: nilfs2_mdt_insert_new_block: inode = ffff88022a8d0178 ino = 3 block = 5
              cp-14635 [000] ...1 30598.200828: nilfs2_mdt_insert_new_block: inode = ffff88022a8d0178 ino = 3 block = 253

Signed-off-by: Hitoshi Mitake 
Signed-off-by: Ryusuke Konishi 
Cc: Steven Rostedt 
Cc: TK Kato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nilfs2: add tracepoints for analyzing sufile manipulation

2015-11-07T01:50:42+00:00

This patch adds tracepoints which would be useful for analyzing segment
usage from a perspective of high level sufile manipulation (check, alloc,
free).  sufile is an important in-place updated metadata file, so
analyzing the behavior would be useful for performance turning.

example of usage (a case of allocation):

$ sudo bin/tpoint nilfs2:nilfs2_segment_usage_allocated
Tracing nilfs2:nilfs2_segment_usage_allocated. Ctrl-C to end.
        segctord-17800 [002] ...1 10671.867294: nilfs2_segment_usage_allocated: sufile = ffff880054f908a8 segnum = 2
        segctord-17800 [002] ...1 10675.073477: nilfs2_segment_usage_allocated: sufile = ffff880054f908a8 segnum = 3

Signed-off-by: Hitoshi Mitake 
Signed-off-by: Ryusuke Konishi 
Cc: Steven Rostedt 
Cc: Benixon Dhas 
Cc: TK Kato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds