kernel.git/fs/ext4/acl.c, branch linux-4.7.y

posix_acl: Inode acl caching fixes

2016-03-31T04:30:15Z

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

2015-04-03T03:47:42Z

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

2014-01-26T04:58:19Z

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

fs: make posix_acl_create more useful

2014-01-26T04:58:18Z

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

2014-01-26T04:58:18Z

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

2013-02-09T20:23:03Z

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()

2013-02-09T02:59:22Z

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

2012-11-08T20:11:11Z

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

userns: Convert extN to support kuids and kgids in posix acls

2012-09-18T08:01:36Z

Convert ext2, ext3, and ext4 to fully support the posix acl changes, using e_uid e_gid instead e_id. Enabled building with posix acls enabled, all filesystems supporting user namespaces, now also support posix acls when user namespaces are enabled. Cc: Theodore Tso Cc: Andrew Morton Cc: Andreas Dilger Cc: Jan Kara Cc: Al Viro Signed-off-by: Eric W. Biederman

userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattr

2012-09-18T08:01:35Z

- Pass the user namespace the uid and gid values in the xattr are stored in into posix_acl_from_xattr. - Pass the user namespace kuid and kgid values should be converted into when storing uid and gid values in an xattr in posix_acl_to_xattr. - Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to pass in &init_user_ns. In the short term this change is not strictly needed but it makes the code clearer. In the longer term this change is necessary to be able to mount filesystems outside of the initial user namespace that natively store posix acls in the linux xattr format. Cc: Theodore Tso Cc: Andrew Morton Cc: Andreas Dilger Cc: Jan Kara Cc: Al Viro Signed-off-by: "Eric W. Biederman"