Commit Graph

8 Commits

Author SHA1 Message Date
Anton Altaparmakov ba6d2377c8 NTFS: Fix a nasty deadlock that appeared in recent kernels.
The situation: VFS inode X on a mounted ntfs volume is dirty.  For
      same inode X, the ntfs_inode is dirty and thus corresponding on-disk
      inode, i.e. mft record, which is in a dirty PAGE_CACHE_PAGE belonging
      to the table of inodes, i.e. $MFT, inode 0.
      What happens:
      Process 1: sys_sync()/umount()/whatever...  calls
      __sync_single_inode() for $MFT -> do_writepages() -> write_page for
      the dirty page containing the on-disk inode X, the page is now locked
      -> ntfs_write_mst_block() which clears PageUptodate() on the page to
      prevent anyone else getting hold of it whilst it does the write out.
      This is necessary as the on-disk inode needs "fixups" applied before
      the write to disk which are removed again after the write and
      PageUptodate is then set again.  It then analyses the page looking
      for dirty on-disk inodes and when it finds one it calls
      ntfs_may_write_mft_record() to see if it is safe to write this
      on-disk inode.  This then calls ilookup5() to check if the
      corresponding VFS inode is in icache().  This in turn calls ifind()
      which waits on the inode lock via wait_on_inode whilst holding the
      global inode_lock.
      Process 2: pdflush results in a call to __sync_single_inode for the
      same VFS inode X on the ntfs volume.  This locks the inode (I_LOCK)
      then calls write-inode -> ntfs_write_inode -> map_mft_record() ->
      read_cache_page() for the page (in page cache of table of inodes
      $MFT, inode 0) containing the on-disk inode.  This page has
      PageUptodate() clear because of Process 1 (see above) so
      read_cache_page() blocks when it tries to take the page lock for the
      page so it can call ntfs_read_page().
      Thus Process 1 is holding the page lock on the page containing the
      on-disk inode X and it is waiting on the inode X to be unlocked in
      ifind() so it can write the page out and then unlock the page.
      And Process 2 is holding the inode lock on inode X and is waiting for
      the page to be unlocked so it can call ntfs_readpage() or discover
      that Process 1 set PageUptodate() again and use the page.
      Thus we have a deadlock due to ifind() waiting on the inode lock.
      The solution: The fix is to use the newly introduced
      ilookup5_nowait() which does not wait on the inode's lock and hence
      avoids the deadlock.  This is safe as we do not care about the VFS
      inode and only use the fact that it is in the VFS inode cache and the
      fact that the vfs and ntfs inodes are one struct in memory to find
      the ntfs inode in memory if present.  Also, the ntfs inode has its
      own locking so it does not matter if the vfs inode is locked.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-06-26 22:12:02 +01:00
Anton Altaparmakov fa3be92317 NTFS: Add an extra parameter @last_vcn to ntfs_get_size_for_mapping_pairs()
and ntfs_mapping_pairs_build() to allow the runlist encoding to be
      partial which is desirable when filling holes in sparse attributes.
      Update all callers.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-06-25 17:15:36 +01:00
Anton Altaparmakov c0c1cc0e46 NTFS: - Fix bug in fs/ntfs/attrib.c::ntfs_find_vcn_nolock() where after
dropping the read lock and taking the write lock we were not checking
        whether someone else did not already do the work we wanted to do.
      - Rename ntfs_find_vcn_nolock() to ntfs_attr_find_vcn_nolock().
      - Tidy up some comments in fs/ntfs/runlist.c.
      - Add LCN_ENOMEM and LCN_EIO definitions to fs/ntfs/runlist.h.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-05-05 11:20:49 +01:00
Randy Dunlap 8907547d4b NTFS: Fix printk format warnings on ia64. (Randy Dunlap)
Signed-off-by: Randy Dunlap <rddunlap@osdl.org>
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-05-05 11:11:47 +01:00
Anton Altaparmakov b6ad6c52fe NTFS: - Split ntfs_map_runlist() into ntfs_map_runlist() and a non-locking
helper ntfs_map_runlist_nolock() which is used by ntfs_map_runlist().
	This allows us to map runlist fragments with the runlist lock already
	held without having to drop and reacquire it around the call.  Adapt
	all callers.
      - Change ntfs_find_vcn() to ntfs_find_vcn_nolock() which takes a locked
	runlist.  This allows us to find runlist elements with the runlist
	lock already held without having to drop and reacquire it around the
	call.  Adapt all callers.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-05-05 10:56:31 +01:00
Anton Altaparmakov 3834c3f227 NTFS: Fix stupid bug in fs/ntfs/mft.c introduced in last changeset.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-05-05 10:45:36 +01:00
Anton Altaparmakov 07a4e2da7d NTFS: Use i_size_{read,write}() in fs/ntfs/{aops.c,mft.c} and protect
access to the i_size and other size fields using the size_lock.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
2005-05-05 10:39:08 +01:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00