linux-toradex.git/fs/ext4/super.c, branch v3.2.32

ext4: fix long mount times on very big file systems

2012-09-12T02:37:07+00:00

commit 0548bbb85337e532ca2ed697c3e9b227ff2ed4b4 upstream.

Commit 8aeb00ff85a: "ext4: fix overhead calculation used by
ext4_statfs()" introduced a O(n**2) calculation which makes very large
file systems take forever to mount.  Fix this with an optimization for
non-bigalloc file systems.  (For bigalloc file systems the overhead
needs to be set in the the superblock.)

Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Ben Hutchings

ext4: avoid kmemcheck complaint from reading uninitialized memory

2012-09-12T02:36:50+00:00

commit 7e731bc9a12339f344cddf82166b82633d99dd86 upstream.

Commit 03179fe923 introduced a kmemcheck complaint in
ext4_da_get_block_prep() because we save and restore
ei->i_da_metadata_calc_last_lblock even though it is left
uninitialized in the case where i_da_metadata_calc_len is zero.

This doesn't hurt anything, but silencing the kmemcheck complaint
makes it easier for people to find real bugs.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=45631
(which is marked as a regression).

Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Ben Hutchings

ext4: fix overhead calculation used by ext4_statfs()

2012-08-02T13:37:45+00:00

commit 952fc18ef9ec707ebdc16c0786ec360295e5ff15 upstream.

Commit f975d6bcc7a introduced bug which caused ext4_statfs() to
miscalculate the number of file system overhead blocks.  This causes
the f_blocks field in the statfs structure to be larger than it should
be.  This would in turn cause the "df" output to show the number of
data blocks in the file system and the number of data blocks used to
be larger than they should be.

Signed-off-by: "Theodore Ts'o" 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

ext4: Report max_batch_time option correctly

2012-07-25T03:11:00+00:00

commit 1d526fc91bea04ee35b7599bf8b82f86c0aaf46c upstream.

Currently the value reported for max_batch_time is really the
value of min_batch_time.

Reported-by: Russell Coker 
Signed-off-by: Ben Hutchings

ext4: add missing save_error_info() to ext4_error()

2012-06-10T13:41:51+00:00

commit f3fc0210c0fc91900766c995f089c39170e68305 upstream.

The ext4_error() function is missing a call to save_error_info().
Since this is the function which marks the file system as containing
an error, this oversight (which was introduced in 2.6.36) is quite
significant, and should be backported to older stable kernels with
high urgency.

Reported-by: Ken Sumrall 
Signed-off-by: "Theodore Ts'o" 
Cc: ksumrall@google.com
Signed-off-by: Ben Hutchings

ext4: force ro mount if ext4_setup_super() fails

2012-06-10T13:41:49+00:00

commit 7e84b6216467b84cd332c8e567bf5aa113fd2f38 upstream.

If ext4_setup_super() fails i.e. due to a too-high revision,
the error is logged in dmesg but the fs is not mounted RO as
indicated.

Tested by:

# mkfs.ext4 -r 4 /dev/sdb6
# mount /dev/sdb6 /mnt/test
# dmesg | grep "too high"
[164919.759248] EXT4-fs (sdb6): revision level too high, forcing read-only mode
# grep sdb6 /proc/mounts
/dev/sdb6 /mnt/test2 ext4 rw,seclabel,relatime,data=ordered 0 0

Reviewed-by: Andreas Dilger 
Signed-off-by: Eric Sandeen 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Ben Hutchings

ext4: address scalability issue by removing extent cache statistics

2012-04-22T22:30:59+00:00

commit 9cd70b347e9761ea2d2ac3d758c529a48a8193e6 upstream.

Andi Kleen and Tim Chen have reported that under certain circumstances
the extent cache statistics are causing scalability problems due to
cache line bounces.

Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: fix undefined behavior in ext4_fill_flex_info()

2012-01-26T00:13:07+00:00

commit d50f2ab6f050311dbf7b8f5501b25f0bf64a439b upstream.

Commit 503358ae01b70ce6909d19dd01287093f6b6271c ("ext4: avoid divide by
zero when trying to mount a corrupted file system") fixes CVE-2009-4307
by performing a sanity check on s_log_groups_per_flex, since it can be
set to a bogus value by an attacker.

	sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
	groups_per_flex = 1 << sbi->s_log_groups_per_flex;

	if (groups_per_flex < 2) { ... }

This patch fixes two potential issues in the previous commit.

1) The sanity check might only work on architectures like PowerPC.
On x86, 5 bits are used for the shifting amount.  That means, given a
large s_log_groups_per_flex value like 36, groups_per_flex = 1 << 36
is essentially 1 << 4 = 16, rather than 0.  This will bypass the check,
leaving s_log_groups_per_flex and groups_per_flex inconsistent.

2) The sanity check relies on undefined behavior, i.e., oversized shift.
A standard-confirming C compiler could rewrite the check in unexpected
ways.  Consider the following equivalent form, assuming groups_per_flex
is unsigned for simplicity.

	groups_per_flex = 1 << sbi->s_log_groups_per_flex;
	if (groups_per_flex == 0 || groups_per_flex == 1) {

We compile the code snippet using Clang 3.0 and GCC 4.6.  Clang will
completely optimize away the check groups_per_flex == 0, leaving the
patched code as vulnerable as the original.  GCC keeps the check, but
there is no guarantee that future versions will do the same.

Signed-off-by: Xi Wang 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: display the correct mount option in /proc/mounts for [no]init_itable

2011-12-13T03:06:18+00:00

/proc/mounts was showing the mount option [no]init_inode_table when
the correct mount option that will be accepted by parse_options() is
[no]init_itable.

Signed-off-by: "Theodore Ts'o" 
Cc: stable@kernel.org

ext4: Remove kernel_lock annotations

2011-11-07T15:50:09+00:00

The BKL is gone, these annotations are useless.

Signed-off-by: Richard Weinberger 
Signed-off-by: "Theodore Ts'o"