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  1. 11 Mar, 2020 2 commits
  3. 28 Feb, 2020 3 commits
  5. 23 Jan, 2020 2 commits
  7. 21 May, 2019 1 commit
  9. 16 Jan, 2019 1 commit
    • Theodore Ts'o's avatar
      ext4: avoid kernel warning when writing the superblock to a dead device · c173c384
      Theodore Ts'o authored 
      commit e8680786

 upstream.

The xfstests generic/475 test switches the underlying device with
dm-error while running a stress test.  This results in a large number
of file system errors, and since we can't lock the buffer head when
marking the superblock dirty in the ext4_grp_locked_error() case, it's
possible the superblock to be !buffer_uptodate() without
buffer_write_io_error() being true.

We need to set buffer_uptodate() before we call mark_buffer_dirty() or
this will trigger a WARN_ON.  It's safe to do this since the
superblock must have been properly read into memory or the mount would
have been successful.  So if buffer_uptodate() is not set, we can
safely assume that this happened due to a failed attempt to write the
superblock.
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c173c384
  11. 09 Jan, 2019 2 commits
  13. 21 Nov, 2018 2 commits
  15. 29 Sep, 2018 2 commits
  17. 15 Aug, 2018 1 commit
    • Theodore Ts'o's avatar
      ext4: fix check to prevent initializing reserved inodes · 954e572a
      Theodore Ts'o authored 
      commit 50122847 upstream.

Commit 8844618d: "ext4: only look at the bg_flags field if it is
valid" will complain if block group zero does not have the
EXT4_BG_INODE_ZEROED flag set.  Unfortunately, this is not correct,
since a freshly created file system has this flag cleared.  It gets
almost immediately after the file system is mounted read-write --- but
the following somewhat unlikely sequence will end up triggering a
false positive report of a corrupted file system:

   mkfs.ext4 /dev/vdc
   mount -o ro /dev/vdc /vdc
   mount -o remount,rw /dev/vdc

Instead, when initializing the inode table for block group zero, test
to make sure that itable_unused count is not too large, since that is
the case that will result in some or all of the reserved inodes
getting cleared.

This fixes the failures reported by Eric Whiteney when running
generic/230 and generic/231 in the the nojournal test case.

Fixes: 8844618d

 ("ext4: only look at the bg_flags field if it is valid")
Reported-by: default avatarEric Whitney <enwlinux@gmail.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      954e572a
  19. 09 Aug, 2018 1 commit
  21. 11 Jul, 2018 5 commits
  23. 24 Apr, 2018 1 commit
  25. 22 Feb, 2018 1 commit
  27. 08 Nov, 2017 1 commit
  29. 27 Sep, 2017 2 commits
  31. 26 Mar, 2017 1 commit
  33. 12 Mar, 2017 2 commits
  35. 09 Feb, 2017 1 commit
    • Eryu Guan's avatar
      ext4: validate s_first_meta_bg at mount time · 13e6ef99
      Eryu Guan authored 
      commit 3a4b77cd

 upstream.

Ralf Spenneberg reported that he hit a kernel crash when mounting a
modified ext4 image. And it turns out that kernel crashed when
calculating fs overhead (ext4_calculate_overhead()), this is because
the image has very large s_first_meta_bg (debug code shows it's
842150400), and ext4 overruns the memory in count_overhead() when
setting bitmap buffer, which is PAGE_SIZE.

ext4_calculate_overhead():
  buf = get_zeroed_page(GFP_NOFS);  <=== PAGE_SIZE buffer
  blks = count_overhead(sb, i, buf);

count_overhead():
  for (j = ext4_bg_num_gdb(sb, grp); j > 0; j--) { <=== j = 842150400
          ext4_set_bit(EXT4_B2C(sbi, s++), buf);   <=== buffer overrun
          count++;
  }

This can be reproduced easily for me by this script:

  #!/bin/bash
  rm -f fs.img
  mkdir -p /mnt/ext4
  fallocate -l 16M fs.img
  mke2fs -t ext4 -O bigalloc,meta_bg,^resize_inode -F fs.img
  debugfs -w -R "ssv first_meta_bg 842150400" fs.img
  mount -o loop fs.img /mnt/ext4

Fix it by validating s_first_meta_bg first at mount time, and
refusing to mount if its value exceeds the largest possible meta_bg
number.
Reported-by: default avatarRalf Spenneberg <ralf@os-t.de>
Signed-off-by: default avatarEryu Guan <guaneryu@gmail.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarAndreas Dilger <adilger@dilger.ca>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      13e6ef99
  37. 06 Jan, 2017 5 commits
    • Sergey Karamov's avatar
      ext4: do not perform data journaling when data is encrypted · 9abce3ca
      Sergey Karamov authored 
      commit 73b92a2a upstream.

Currently data journalling is incompatible with encryption: enabling both
at the same time has never been supported by design, and would result in
unpredictable behavior. However, users are not precluded from turning on
both features simultaneously. This change programmatically replaces data
journaling for encrypted regular files with ordered data journaling mode.

Background:
Journaling encrypted data has not been supported because it operates on
buffer heads of the page in the page cache. Namely, when the commit
happens, which could be up to five seconds after caching, the commit
thread uses the buffer heads attached to the page to copy the contents of
the page to the journal. With encryption, it would have been required to
keep the bounce buffer with ciphertext for up to the aforementioned five
seconds, since the page cache can only hold plaintext and could not be
used for journaling. Alternatively, it would be required to setup the
journal to initiate a callback at the commit time to perform deferred
encryption - in this case, not only would the data have to be written
twice, but it would also have to be encrypted twice. This level of
complexity was not justified for a mode that in practice is very rarely
used because of the overhead from the data journalling.

Solution:
If data=journaled has been set as a mount option for a filesystem, or if
journaling is enabled on a regular file, do not perform journaling if the
file is also encrypted, instead fall back to the data=ordered mode for the
file.

Rationale:
The intent is to allow seamless and proper filesystem operation when
journaling and encryption have both been enabled, and have these two
conflicting features gracefully resolved by the filesystem.

Fixes: 44614711

Signed-off-by: default avatarSergey Karamov <skaramov@google.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9abce3ca
    • Theodore Ts'o's avatar
      ext4: add sanity checking to count_overhead() · 8084f57b
      Theodore Ts'o authored 
      commit c48ae41b

 upstream.

The commit "ext4: sanity check the block and cluster size at mount
time" should prevent any problems, but in case the superblock is
modified while the file system is mounted, add an extra safety check
to make sure we won't overrun the allocated buffer.
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8084f57b
    • Theodore Ts'o's avatar
      ext4: fix in-superblock mount options processing · 956e2a0e
      Theodore Ts'o authored 
      commit 5aee0f8a

 upstream.

Fix a large number of problems with how we handle mount options in the
superblock.  For one, if the string in the superblock is long enough
that it is not null terminated, we could run off the end of the string
and try to interpret superblocks fields as characters.  It's unlikely
this will cause a security problem, but it could result in an invalid
parse.  Also, parse_options is destructive to the string, so in some
cases if there is a comma-separated string, it would be modified in
the superblock.  (Fortunately it only happens on file systems with a
1k block size.)
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      956e2a0e
    • Theodore Ts'o's avatar
      ext4: use more strict checks for inodes_per_block on mount · 01772f46
      Theodore Ts'o authored 
      commit cd6bb35b

 upstream.

Centralize the checks for inodes_per_block and be more strict to make
sure the inodes_per_block_group can't end up being zero.
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarAndreas Dilger <adilger@dilger.ca>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      01772f46
    • Theodore Ts'o's avatar
      ext4: don't lock buffer in ext4_commit_super if holding spinlock · 24d1251a
      Theodore Ts'o authored 
      commit 1566a48a upstream.

If there is an error reported in mballoc via ext4_grp_locked_error(),
the code is holding a spinlock, so ext4_commit_super() must not try to
lock the buffer head, or else it will trigger a BUG:

  BUG: sleeping function called from invalid context at ./include/linux/buffer_head.h:358
  in_atomic(): 1, irqs_disabled(): 0, pid: 993, name: mount
  CPU: 0 PID: 993 Comm: mount Not tainted 4.9.0-rc1-clouder1 #62
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014
   ffff880006423548 ffffffff81318c89 ffffffff819ecdd0 0000000000000166
   ffff880006423558 ffffffff810810b0 ffff880006423580 ffffffff81081153
   ffff880006e5a1a0 ffff88000690e400 0000000000000000 ffff8800064235c0
  Call Trace:
    [<ffffffff81318c89>] dump_stack+0x67/0x9e
    [<ffffffff810810b0>] ___might_sleep+0xf0/0x140
    [<ffffffff81081153>] __might_sleep+0x53/0xb0
    [<ffffffff8126c1dc>] ext4_commit_super+0x19c/0x290
    [<ffffffff8126e61a>] __ext4_grp_locked_error+0x14a/0x230
    [<ffffffff81081153>] ? __might_sleep+0x53/0xb0
    [<ffffffff812822be>] ext4_mb_generate_buddy+0x1de/0x320

Since ext4_grp_locked_error() calls ext4_commit_super with sync == 0
(and it is the only caller which does so), avoid locking and unlocking
the buffer in this case.

This can result in races with ext4_commit_super() if there are other
problems (which is what commit 4743f839 was trying to address),
but a Warning is better than BUG.

Fixes: 4743f839

Reported-by: default avatarNikolay Borisov <kernel@kyup.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      24d1251a
  39. 20 Nov, 2016 1 commit
  41. 13 Oct, 2016 1 commit
  43. 30 Sep, 2016 2 commits
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