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  1. 03 9月, 2011 1 次提交
    • A
      ext4: Add new ext4_discard_partial_page_buffers routines · 4e96b2db
      由 Allison Henderson 提交于 
      This patch adds two new routines: ext4_discard_partial_page_buffers
and ext4_discard_partial_page_buffers_no_lock.

The ext4_discard_partial_page_buffers routine is a wrapper
function to ext4_discard_partial_page_buffers_no_lock.
The wrapper function locks the page and passes it to
ext4_discard_partial_page_buffers_no_lock.
Calling functions that already have the page locked can call
ext4_discard_partial_page_buffers_no_lock directly.

The ext4_discard_partial_page_buffers_no_lock function
zeros a specified range in a page, and unmaps the
corresponding buffer heads.  Only block aligned regions of the
page will have their buffer heads unmapped.  Unblock aligned regions
will be mapped if needed so that they can be updated with the
partial zero out.  This function is meant to
be used to update a page and its buffer heads to be zeroed
and unmapped when the corresponding blocks have been released
or will be released.

This routine is used in the following scenarios:
* A hole is punched and the non page aligned regions
  of the head and tail of the hole need to be discarded

* The file is truncated and the partial page beyond EOF needs
  to be discarded

* The end of a hole is in the same page as EOF.  After the
  page is flushed, the partial page beyond EOF needs to be
  discarded.

* A write operation begins or ends inside a hole and the partial
  page appearing before or after the write needs to be discarded

* A write operation extends EOF and the partial page beyond EOF
  needs to be discarded

This function takes a flag EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
which is used when a write operation begins or ends in a hole.
When the EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED flag is used, only
buffer heads that are already unmapped will have the corresponding
regions of the page zeroed.
Signed-off-by: NAllison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
      4e96b2db
  3. 01 9月, 2011 2 次提交
  5. 31 8月, 2011 4 次提交
    • D
      ext4: ext4_rename should dirty dir_bh with the correct directory · bcaa9929
      由 Darrick J. Wong 提交于 
      When ext4_rename performs a directory rename (move), dir_bh is a
buffer that is modified to update the '..' link in the directory being
moved (old_inode).  However, ext4_handle_dirty_metadata is called with
the old parent directory inode (old_dir) and dir_bh, which is
incorrect because dir_bh does not belong to the parent inode.  Fix
this error.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
      bcaa9929
    • T
      ext4: fake direct I/O mode for data=journal · 84ebd795
      由 Theodore Ts'o 提交于 
      Currently attempts to open a file with O_DIRECT in data=journal mode
causes the open to fail with -EINVAL.  This makes it very hard to test
data=journal mode.  So we will let the open succeed, but then always
fall back to O_DSYNC buffered writes.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
      84ebd795
    • T
      ext2,ext3,ext4: don't inherit APPEND_FL or IMMUTABLE_FL for new inodes · 1cd9f097
      由 Theodore Ts'o 提交于 
      This doesn't make much sense, and it exposes a bug in the kernel where
attempts to create a new file in an append-only directory using
O_CREAT will fail (but still leave a zero-length file).  This was
discovered when xfstests #79 was generalized so it could run on all
file systems.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc:stable@kernel.org
      1cd9f097
    • J
      ext4: remove i_mutex lock in ext4_evict_inode to fix lockdep complaining · 8c0bec21
      由 Jiaying Zhang 提交于 
      The i_mutex lock and flush_completed_IO() added by commit 2581fdc8
in ext4_evict_inode() causes lockdep complaining about potential
deadlock in several places.  In most/all of these LOCKDEP complaints
it looks like it's a false positive, since many of the potential
circular locking cases can't take place by the time the
ext4_evict_inode() is called; but since at the very least it may mask
real problems, we need to address this.

This change removes the flush_completed_IO() and i_mutex lock in
ext4_evict_inode().  Instead, we take a different approach to resolve
the software lockup that commit 2581fdc8 intends to fix.  Rather
than having ext4-dio-unwritten thread wait for grabing the i_mutex
lock of an inode, we use mutex_trylock() instead, and simply requeue
the work item if we fail to grab the inode's i_mutex lock.

This should speed up work queue processing in general and also
prevents the following deadlock scenario: During page fault,
shrink_icache_memory is called that in turn evicts another inode B.
Inode B has some pending io_end work so it calls ext4_ioend_wait()
that waits for inode B's i_ioend_count to become zero.  However, inode
B's ioend work was queued behind some of inode A's ioend work on the
same cpu's ext4-dio-unwritten workqueue.  As the ext4-dio-unwritten
thread on that cpu is processing inode A's ioend work, it tries to
grab inode A's i_mutex lock.  Since the i_mutex lock of inode A is
still hold before the page fault happened, we enter a deadlock.
Signed-off-by: NJiaying Zhang <jiayingz@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
      8c0bec21
  7. 23 8月, 2011 3 次提交
  9. 22 8月, 2011 3 次提交
  11. 21 8月, 2011 4 次提交
  13. 20 8月, 2011 8 次提交
  15. 19 8月, 2011 15 次提交