linux.git/fs/btrfs/compression.c, branch v3.14

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

2014-02-09T19:12:26+00:00

Pull btrfs fixes from Chris Mason:
 "This is a small collection of fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix data corruption when reading/updating compressed extents
  Btrfs: don't loop forever if we can't run because of the tree mod log
  btrfs: reserve no transaction units in btrfs_ioctl_set_features
  btrfs: commit transaction after setting label and features
  Btrfs: fix assert screwup for the pending move stuff

Btrfs: fix data corruption when reading/updating compressed extents

2014-02-09T01:57:15+00:00

When using a mix of compressed file extents and prealloc extents, it
is possible to fill a page of a file with random, garbage data from
some unrelated previous use of the page, instead of a sequence of zeroes.

A simple sequence of steps to get into such case, taken from the test
case I made for xfstests, is:

   _scratch_mkfs
   _scratch_mount "-o compress-force=lzo"
   $XFS_IO_PROG -f -c "pwrite -S 0x06 -b 18670 266978 18670" $SCRATCH_MNT/foobar
   $XFS_IO_PROG -c "falloc 26450 665194" $SCRATCH_MNT/foobar
   $XFS_IO_PROG -c "truncate 542872" $SCRATCH_MNT/foobar
   $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar

This results in the following file items in the fs tree:

   item 4 key (257 INODE_ITEM 0) itemoff 15879 itemsize 160
       inode generation 6 transid 6 size 542872 block group 0 mode 100600
   item 5 key (257 INODE_REF 256) itemoff 15863 itemsize 16
       inode ref index 2 namelen 6 name: foobar
   item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53
       extent data disk byte 0 nr 0 gen 6
       extent data offset 0 nr 24576 ram 266240
       extent compression 0
   item 7 key (257 EXTENT_DATA 24576) itemoff 15757 itemsize 53
       prealloc data disk byte 12849152 nr 241664 gen 6
       prealloc data offset 0 nr 241664
   item 8 key (257 EXTENT_DATA 266240) itemoff 15704 itemsize 53
       extent data disk byte 12845056 nr 4096 gen 6
       extent data offset 0 nr 20480 ram 20480
       extent compression 2
   item 9 key (257 EXTENT_DATA 286720) itemoff 15651 itemsize 53
       prealloc data disk byte 13090816 nr 405504 gen 6
       prealloc data offset 0 nr 258048

The on disk extent at offset 266240 (which corresponds to 1 single disk block),
contains 5 compressed chunks of file data. Each of the first 4 compress 4096
bytes of file data, while the last one only compresses 3024 bytes of file data.
Therefore a read into the file region [285648 ; 286720[ (length = 4096 - 3024 =
1072 bytes) should always return zeroes (our next extent is a prealloc one).

The solution here is the compression code path to zero the remaining (untouched)
bytes of the last page it uncompressed data into, as the information about how
much space the file data consumes in the last page is not known in the upper layer
fs/btrfs/extent_io.c:__do_readpage(). In __do_readpage we were correctly zeroing
the remainder of the page but only if it corresponds to the last page of the inode
and if the inode's size is not a multiple of the page size.

This would cause not only returning random data on reads, but also permanently
storing random data when updating parts of the region that should be zeroed.
For the example above, it means updating a single byte in the region [285648 ; 286720[
would store that byte correctly but also store random data on disk.

A test case for xfstests follows soon.

Signed-off-by: Filipe David Borba Manana 
Signed-off-by: Chris Mason

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

2014-01-31T04:08:20+00:00

Pull btrfs updates from Chris Mason:
 "This is a pretty big pull, and most of these changes have been
  floating in btrfs-next for a long time.  Filipe's properties work is a
  cool building block for inheriting attributes like compression down on
  a per inode basis.

  Jeff Mahoney kicked in code to export filesystem info into sysfs.

  Otherwise, lots of performance improvements, cleanups and bug fixes.

  Looks like there are still a few other small pending incrementals, but
  I wanted to get the bulk of this in first"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (149 commits)
  Btrfs: fix spin_unlock in check_ref_cleanup
  Btrfs: setup inode location during btrfs_init_inode_locked
  Btrfs: don't use ram_bytes for uncompressed inline items
  Btrfs: fix btrfs_search_slot_for_read backwards iteration
  Btrfs: do not export ulist functions
  Btrfs: rework ulist with list+rb_tree
  Btrfs: fix memory leaks on walking backrefs failure
  Btrfs: fix send file hole detection leading to data corruption
  Btrfs: add a reschedule point in btrfs_find_all_roots()
  Btrfs: make send's file extent item search more efficient
  Btrfs: fix to catch all errors when resolving indirect ref
  Btrfs: fix protection between walking backrefs and root deletion
  btrfs: fix warning while merging two adjacent extents
  Btrfs: fix infinite path build loops in incremental send
  btrfs: undo sysfs when open_ctree() fails
  Btrfs: fix snprintf usage by send's gen_unique_name
  btrfs: fix defrag 32-bit integer overflow
  btrfs: sysfs: list the NO_HOLES feature
  btrfs: sysfs: don't show reserved incompat feature
  btrfs: call permission checks earlier in ioctls and return EPERM
  ...

Btrfs: convert printk to btrfs_ and fix BTRFS prefix

2014-01-28T21:20:05+00:00

Convert all applicable cases of printk and pr_* to the btrfs_* macros.

Fix all uses of the BTRFS prefix.

Signed-off-by: Frank Holton 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

block: Abstract out bvec iterator

2013-11-24T06:33:47+00:00

Immutable biovecs are going to require an explicit iterator. To
implement immutable bvecs, a later patch is going to add a bi_bvec_done
member to this struct; for now, this patch effectively just renames
things.

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe 
Cc: Geert Uytterhoeven 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "Ed L. Cashin" 
Cc: Nick Piggin 
Cc: Lars Ellenberg 
Cc: Jiri Kosina 
Cc: Matthew Wilcox 
Cc: Geoff Levand 
Cc: Yehuda Sadeh 
Cc: Sage Weil 
Cc: Alex Elder 
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris 
Cc: Philip Kelleher 
Cc: Rusty Russell 
Cc: "Michael S. Tsirkin" 
Cc: Konrad Rzeszutek Wilk 
Cc: Jeremy Fitzhardinge 
Cc: Neil Brown 
Cc: Alasdair Kergon 
Cc: Mike Snitzer 
Cc: dm-devel@redhat.com
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: linux390@de.ibm.com
Cc: Boaz Harrosh 
Cc: Benny Halevy 
Cc: "James E.J. Bottomley" 
Cc: Greg Kroah-Hartman 
Cc: "Nicholas A. Bellinger" 
Cc: Alexander Viro 
Cc: Chris Mason 
Cc: "Theodore Ts'o" 
Cc: Andreas Dilger 
Cc: Jaegeuk Kim 
Cc: Steven Whitehouse 
Cc: Dave Kleikamp 
Cc: Joern Engel 
Cc: Prasad Joshi 
Cc: Trond Myklebust 
Cc: KONISHI Ryusuke 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Ben Myers 
Cc: xfs@oss.sgi.com
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Len Brown 
Cc: Pavel Machek 
Cc: "Rafael J. Wysocki" 
Cc: Herton Ronaldo Krzesinski 
Cc: Ben Hutchings 
Cc: Andrew Morton 
Cc: Guo Chao 
Cc: Tejun Heo 
Cc: Asai Thambi S P 
Cc: Selvan Mani 
Cc: Sam Bradshaw 
Cc: Wei Yongjun 
Cc: "Roger Pau Monné" 
Cc: Jan Beulich 
Cc: Stefano Stabellini 
Cc: Ian Campbell 
Cc: Sebastian Ott 
Cc: Christian Borntraeger 
Cc: Minchan Kim 
Cc: Jiang Liu 
Cc: Nitin Gupta 
Cc: Jerome Marchand 
Cc: Joe Perches 
Cc: Peng Tao 
Cc: Andy Adamson 
Cc: fanchaoting 
Cc: Jie Liu 
Cc: Sunil Mushran 
Cc: "Martin K. Petersen" 
Cc: Namjae Jeon 
Cc: Pankaj Kumar 
Cc: Dan Magenheimer 
Cc: Mel Gorman 6

block: Convert various code to bio_for_each_segment()

2013-11-24T06:33:46+00:00

With immutable biovecs we don't want code accessing bi_io_vec directly -
the uses this patch changes weren't incorrect since they all own the
bio, but it makes the code harder to audit for no good reason - also,
this will help with multipage bvecs later.

Signed-off-by: Kent Overstreet 
Cc: Jens Axboe 
Cc: Alexander Viro 
Cc: Chris Mason 
Cc: Jaegeuk Kim 
Cc: Joern Engel 
Cc: Prasad Joshi 
Cc: Trond Myklebust

btrfs: Fix checkpatch.pl warning of spacing issues

2013-11-12T03:12:31+00:00

Fix spacing issues detected via checkpatch.pl in accordance with the
kernel style guidelines.

Signed-off-by: Dulshani Gunawardhana 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

btrfs: remove fs/btrfs/compat.h

2013-11-12T03:03:19+00:00

fs/btrfs/compat.h only contained trivial macro wrappers of drop_nlink()
and inc_nlink().  This doesn't belong in mainline.

Signed-off-by: Zach Brown 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

Btrfs: Remove superfluous casts from u64 to unsigned long long

2013-09-01T12:16:08+00:00

u64 is "unsigned long long" on all architectures now, so there's no need to
cast it when formatting it using the "ll" length modifier.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason

btrfs: Introduce extent_read_full_page_nolock()

2013-09-01T12:04:59+00:00

We want this for btrfs_extent_same. Basically readpage and friends do their
own extent locking but for the purposes of dedupe, we want to have both
files locked down across a set of readpage operations (so that we can
compare data). Introduce this variant and a flag which can be set for
extent_read_full_page() to indicate that we are already locked.

Partial credit for this patch goes to Gabriel de Perthuis 
as I have included a fix from him to the original patch which avoids a
deadlock on compressed extents.

Signed-off-by: Mark Fasheh 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason