linux-toradex.git/fs/ext4/acl.c, branch v4.10

ext4: use current_time() for inode timestamps

2016-11-15T02:40:10+00:00

CURRENT_TIME_SEC and CURRENT_TIME are not y2038 safe.
current_time() will be transitioned to be y2038 safe
along with vfs.

current_time() returns timestamps according to the
granularities set in the super_block.
The granularity check in ext4_current_time() to call
current_time() or CURRENT_TIME_SEC is not required.
Use current_time() directly to obtain timestamps
unconditionally, and remove ext4_current_time().

Quota files are assumed to be on the same filesystem.
Hence, use current_time() for these files as well.

Signed-off-by: Deepa Dinamani 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Arnd Bergmann

posix_acl: Clear SGID bit when setting file permissions

2016-09-22T08:55:32+00:00

When file permissions are modified via chmod(2) and the user is not in
the owning group or capable of CAP_FSETID, the setgid bit is cleared in
inode_change_ok().  Setting a POSIX ACL via setxattr(2) sets the file
permissions as well as the new ACL, but doesn't clear the setgid bit in
a similar way; this allows to bypass the check in chmod(2).  Fix that.

References: CVE-2016-7097
Reviewed-by: Christoph Hellwig 
Reviewed-by: Jeff Layton 
Signed-off-by: Jan Kara 
Signed-off-by: Andreas Gruenbacher

posix_acl: Inode acl caching fixes

2016-03-31T04:30:15+00:00

When get_acl() is called for an inode whose ACL is not cached yet, the
get_acl inode operation is called to fetch the ACL from the filesystem.
The inode operation is responsible for updating the cached acl with
set_cached_acl().  This is done without locking at the VFS level, so
another task can call set_cached_acl() or forget_cached_acl() before the
get_acl inode operation gets to calling set_cached_acl(), and then
get_acl's call to set_cached_acl() results in caching an outdate ACL.

Prevent this from happening by setting the cached ACL pointer to a
task-specific sentinel value before calling the get_acl inode operation.
Move the responsibility for updating the cached ACL from the get_acl
inode operations to get_acl().  There, only set the cached ACL if the
sentinel value hasn't changed.

The sentinel values are chosen to have odd values.  Likewise, the value
of ACL_NOT_CACHED is odd.  In contrast, ACL object pointers always have
an even value (ACLs are aligned in memory).  This allows to distinguish
uncached ACLs values from ACL objects.

In addition, switch from guarding inode->i_acl and inode->i_default_acl
upates by the inode->i_lock spinlock to using xchg() and cmpxchg().

Filesystems that do not want ACLs returned from their get_acl inode
operations to be cached must call forget_cached_acl() to prevent the VFS
from doing so.

(Patch written by Al Viro and Andreas Gruenbacher.)

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Al Viro

ext4: remove unused header files

2015-04-03T03:47:42+00:00

Remove unused header files and header files which are included in
ext4.h.

Signed-off-by: Sheng Yong 
Signed-off-by: Theodore Ts'o

ext2/3/4: use generic posix ACL infrastructure

2014-01-26T04:58:19+00:00

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

fs: make posix_acl_create more useful

2014-01-26T04:58:18+00:00

Rename the current posix_acl_created to __posix_acl_create and add
a fully featured helper to set up the ACLs on file creation that
uses get_acl().

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

fs: make posix_acl_chmod more useful

2014-01-26T04:58:18+00:00

Rename the current posix_acl_chmod to __posix_acl_chmod and add
a fully featured ACL chmod helper that uses the ->set_acl inode
operation.

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

ext4: fix the number of credits needed for acl ops with inline data

2013-02-09T20:23:03+00:00

Operations which modify extended attributes may need extra journal
credits if inline data is used, since there is a chance that some
extended attributes may need to get pushed to an external attribute
block.

Changes to reflect this was made in xattr.c, but they were missed in
fs/ext4/acl.c.  To fix this, abstract the calculation of the number of
credits needed for xattr operations to an inline function defined in
ext4_jbd2.h, and use it in acl.c and xattr.c.

Also move the function declarations used in inline.c from xattr.h
(where they are non-obviously hidden, and caused problems since
ext4_jbd2.h needs to use the function ext4_has_inline_data), and move
them to ext4.h.

Signed-off-by: "Theodore Ts'o" 
Reviewed-by: Tao Ma 
Reviewed-by: Jan Kara

ext4: pass context information to jbd2__journal_start()

2013-02-09T02:59:22+00:00

So we can better understand what bits of ext4 are responsible for
long-running jbd2 handles, use jbd2__journal_start() so we can pass
context information for logging purposes.

The recommended way for finding the longer-running handles is:

   T=/sys/kernel/debug/tracing
   EVENT=$T/events/jbd2/jbd2_handle_stats
   echo "interval > 5" > $EVENT/filter
   echo 1 > $EVENT/enable

   ./run-my-fs-benchmark

   cat $T/trace > /tmp/problem-handles

This will list handles that were active for longer than 20ms.  Having
longer-running handles is bad, because a commit started at the wrong
time could stall for those 20+ milliseconds, which could delay an
fsync() or an O_SYNC operation.  Here is an example line from the
trace file describing a handle which lived on for 311 jiffies, or over
1.2 seconds:

postmark-2917  [000] ....   196.435786: jbd2_handle_stats: dev 254,32 
   tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1
   dirtied_blocks 0

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

ext4: fix memory leak in ext4_xattr_set_acl()'s error path

2012-11-08T20:11:11+00:00

In ext4_xattr_set_acl(), if ext4_journal_start() returns an error,
posix_acl_release() will not be called for 'acl' which may result in a
memory leak.

This patch fixes that.

Reviewed-by: Lukas Czerner 
Signed-off-by: Eugene Shatokhin 
Signed-off-by: "Theodore Ts'o" 
Cc: stable@vger.kernel.org