1. 14 7月, 2005 8 次提交
    • A
      [PATCH] Fix soft lockup due to NTFS: VFS part and explanation · 88bd5121
      Anton Altaparmakov 提交于
      Something has changed in the core kernel such that we now get concurrent
      inode write outs, one e.g via pdflush and one via sys_sync or whatever.
      This causes a nasty deadlock in ntfs.  The only clean solution
      unfortunately requires a minor vfs api extension.
      
      First the deadlock analysis:
      
      Prerequisive knowledge: NTFS has a file $MFT (inode 0) loaded at mount
      time.  The NTFS driver uses the page cache for storing the file contents as
      usual.  More interestingly this file contains the table of on-disk inodes
      as a sequence of MFT_RECORDs.  Thus NTFS driver accesses the on-disk inodes
      by accessing the MFT_RECORDs in the page cache pages of the loaded inode
      $MFT.
      
      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,
      which is as explained above in a dirty PAGE_CACHE_PAGE belonging to the
      table of inodes ($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() of
      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 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 only sensible solution: NTFS does not care whether the VFS inode is
      locked or not when it calls ilookup5() (it doesn't use the VFS inode at
      all, it just uses it to find the corresponding ntfs_inode which is of
      course attached to the VFS inode (both are one single struct); and it uses
      the ntfs_inode which is subject to its own locking so I_LOCK is irrelevant)
      hence we want a modified ilookup5_nowait() which is the same as ilookup5()
      but it does not wait on the inode lock.
      
      Without such functionality I would have to keep my own ntfs_inode cache in
      the NTFS driver just so I can find ntfs_inodes independent of their VFS
      inodes which would be slow, memory and cpu cycle wasting, and incredibly
      stupid given the icache already exists in the VFS.
      
      Below is a patch that does the ilookup5_nowait() implementation in
      fs/inode.c and exports it.
      
      ilookup5_nowait.diff:
      
      Introduce ilookup5_nowait() which is basically the same as ilookup5() but
      it does not wait on the inode's lock (i.e. it omits the wait_on_inode()
      done in ifind()).
      
      This is needed to avoid a nasty deadlock in NTFS.
      Signed-off-by: NAnton Altaparmakov <aia21@cantab.net>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      88bd5121
    • R
      [PATCH] inotify: misc cleanup · 9a556e89
      Robert Love 提交于
      Really simple, basic cleanup.
      Signed-off-by: NRobert Love <rml@novell.com>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      9a556e89
    • R
      [PATCH] inotify: event ordering · 5995f16b
      Robert Love 提交于
      This rearranges the event ordering for "open" to be consistent with the
      ordering of the other events.
      Signed-off-by: NRobert Love <rml@novell.com>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      5995f16b
    • R
      [PATCH] inotify: move sysctl · 0399cb08
      Robert Love 提交于
      This moves the inotify sysctl knobs to "/proc/sys/fs/inotify" from
      "/proc/sys/fs".  Also some related cleanup.
      Signed-off-by: NRobert Love <rml@novell.com>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      0399cb08
    • J
      [PATCH] fix voyager subarchitecture EXPORT_SYMBOL breakage caused by i386_ksym reduction · 153f8057
      James Bottomley 提交于
      This patch:
      
      	[PATCH] Remove i386_ksyms.c, almost
      
      made files like smp.c do their own EXPORT_SYMBOLS.  This means that all
      subarchitectures that override these symbols now have to do the exports
      themselves.  This patch adds the exports for voyager (which is the most
      affected since it has a separate smp harness).  However, someone should
      audit all the other subarchitectures to see if any others got broken.
      Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      153f8057
    • L
    • J
      [PATCH] Lindent: ignore .indent.pro · c0ac515e
      Jeff Mahoney 提交于
       When I recently submitted a Lindent patch, it turned out that my .indent.pro
       options were also applied to the tree. This patch directs indent(1) to ignore
       the .indent.pro directives and only use options specified on the command
       line.
      Signed-off-by: NJeff Mahoney <jeffm@suse.com>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      c0ac515e
    • L
      Merge /home/torvalds/linux-2.6-arm · 6cd59f7a
      Linus Torvalds 提交于
      6cd59f7a
  2. 13 7月, 2005 32 次提交