linux/fs, branch v3.0.59

GFS2: Test bufdata with buffer locked and gfs2_log_lock held

2013-01-17T16:44:12Z

commit 96e5d1d3adf56f1c7eeb07258f6a1a0a7ae9c489 upstream. In gfs2_trans_add_bh(), gfs2 was testing if a there was a bd attached to the buffer without having the gfs2_log_lock held. It was then assuming it would stay attached for the rest of the function. However, without either the log lock being held of the buffer locked, __gfs2_ail_flush() could detach bd at any time. This patch moves the locking before the test. If there isn't a bd already attached, gfs2 can safely allocate one and attach it before locking. There is no way that the newly allocated bd could be on the ail list, and thus no way for __gfs2_ail_flush() to detach it. Signed-off-by: Benjamin Marzinski Signed-off-by: Steven Whitehouse [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

epoll: prevent missed events on EPOLL_CTL_MOD

2013-01-17T16:43:59Z

commit 128dd1759d96ad36c379240f8b9463e8acfd37a1 upstream. EPOLL_CTL_MOD sets the interest mask before calling f_op->poll() to ensure events are not missed. Since the modifications to the interest mask are not protected by the same lock as ep_poll_callback, we need to ensure the change is visible to other CPUs calling ep_poll_callback. We also need to ensure f_op->poll() has an up-to-date view of past events which occured before we modified the interest mask. So this barrier also pairs with the barrier in wq_has_sleeper(). This should guarantee either ep_poll_callback or f_op->poll() (or both) will notice the readiness of a recently-ready/modified item. This issue was encountered by Andreas Voellmy and Junchang(Jason) Wang in: http://thread.gmane.org/gmane.linux.kernel/1408782/ Signed-off-by: Eric Wong Cc: Hans Verkuil Cc: Jiri Olsa Cc: Jonathan Corbet Cc: Al Viro Cc: Davide Libenzi Cc: Hans de Goede Cc: Mauro Carvalho Chehab Cc: David Miller Cc: Eric Dumazet Cc: Andrew Morton Cc: Andreas Voellmy Tested-by: "Junchang(Jason) Wang" Cc: netdev@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Linus Torvalds [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

udf: don't increment lenExtents while writing to a hole

2013-01-17T16:43:58Z

commit fb719c59bdb4fca86ee1fd1f42ab3735ca12b6b2 upstream. Incrementing lenExtents even while writing to a hole is bad for performance as calls to udf_discard_prealloc and udf_truncate_tail_extent would not return from start if isize != lenExtents Signed-off-by: Namjae Jeon Signed-off-by: Ashish Sangwan Signed-off-by: Jan Kara Signed-off-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman

udf: fix memory leak while allocating blocks during write

2013-01-17T16:43:58Z

commit 2fb7d99d0de3fd8ae869f35ab682581d8455887a upstream. Need to brelse the buffer_head stored in cur_epos and next_epos. Signed-off-by: Namjae Jeon Signed-off-by: Ashish Sangwan Signed-off-by: Jan Kara Signed-off-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman

ext4: lock i_mutex when truncating orphan inodes

2013-01-17T16:43:57Z

commit 721e3eba21e43532e438652dd8f1fcdfce3187e7 upstream. Commit c278531d39 added a warning when ext4_flush_unwritten_io() is called without i_mutex being taken. It had previously not been taken during orphan cleanup since races weren't possible at that point in the mount process, but as a result of this c278531d39, we will now see a kernel WARN_ON in this case. Take the i_mutex in ext4_orphan_cleanup() to suppress this warning. Reported-by: Alexander Beregalov Signed-off-by: "Theodore Ts'o" Reviewed-by: Zheng Liu Signed-off-by: Greg Kroah-Hartman

ext4: do not try to write superblock on ro remount w/o journal

2013-01-17T16:43:57Z

commit d096ad0f79a782935d2e06ae8fb235e8c5397775 upstream. When a journal-less ext4 filesystem is mounted on a read-only block device (blockdev --setro will do), each remount (for other, unrelated, flags, like suid=>nosuid etc) results in a series of scary messages from kernel telling about I/O errors on the device. This is becauese of the following code ext4_remount(): if (sbi->s_journal == NULL) ext4_commit_super(sb, 1); at the end of remount procedure, which forces writing (flushing) of a superblock regardless whenever it is dirty or not, if the filesystem is readonly or not, and whenever the device itself is readonly or not. We only need call ext4_commit_super when the file system had been previously mounted read/write. Thanks to Eric Sandeen for help in diagnosing this issue. Signed-off-By: Michael Tokarev Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

jbd2: fix assertion failure in jbd2_journal_flush()

2013-01-17T16:43:57Z

commit d7961c7fa4d2e3c3f12be67e21ba8799b5a7238a upstream. The following race is possible between start_this_handle() and someone calling jbd2_journal_flush(). Process A Process B start_this_handle(). if (journal->j_barrier_count) # false if (!journal->j_running_transaction) { #true read_unlock(&journal->j_state_lock); jbd2_journal_lock_updates() jbd2_journal_flush() write_lock(&journal->j_state_lock); if (journal->j_running_transaction) { # false ... wait for committing trans ... write_unlock(&journal->j_state_lock); ... write_lock(&journal->j_state_lock); if (!journal->j_running_transaction) { # true jbd2_get_transaction(journal, new_transaction); write_unlock(&journal->j_state_lock); goto repeat; # eventually blocks on j_barrier_count > 0 ... J_ASSERT(!journal->j_running_transaction); # fails We fix the race by rechecking j_barrier_count after reacquiring j_state_lock in exclusive mode. Reported-by: yjwsignal@empal.com Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix extent tree corruption caused by hole punch

2013-01-17T16:43:57Z

commit c36575e663e302dbaa4d16b9c72d2c9a913a9aef upstream. When depth of extent tree is greater than 1, logical start value of interior node is not correctly updated in ext4_ext_rm_idx. Signed-off-by: Forrest Liu Signed-off-by: "Theodore Ts'o" Reviewed-by: Ashish Sangwan Signed-off-by: Greg Kroah-Hartman

jffs2: hold erase_completion_lock on exit

2013-01-17T16:43:55Z

commit 2cbba75a56ea78e6876b4e2547a882f10b3fe72b upstream. Users of jffs2_do_reserve_space() expect they still held erase_completion_lock after call to it. But there is a path where jffs2_do_reserve_space() leaves erase_completion_lock unlocked. The patch fixes it. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov Signed-off-by: Artem Bityutskiy Signed-off-by: Greg Kroah-Hartman

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

2013-01-17T16:43:55Z

commit 24ec19b0ae83a385ad9c55520716da671274b96c upstream. 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" Signed-off-by: Greg Kroah-Hartman