diff options
| author | Anton Altaparmakov <aia21@cam.ac.uk> | 2007-10-12 09:37:15 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-12 09:16:30 -0700 |
| commit | bfab36e81611e60573b84eb4e4b4c8d8545b2320 (patch) | |
| tree | acd151a4c85459dcd2f6575ceb385090ebaaf984 /fs/ntfs/attrib.c | |
| parent | f26e51f67ae6a75ffc57b96cf5fe096f75e778cb (diff) | |
NTFS: Fix a mount time deadlock.
Big thanks go to Mathias Kolehmainen for reporting the bug, providing
debug output and testing the patches I sent him to get it working.
The fix was to stop calling ntfs_attr_set() at mount time as that causes
balance_dirty_pages_ratelimited() to be called which on systems with
little memory actually tries to go and balance the dirty pages which tries
to take the s_umount semaphore but because we are still in fill_super()
across which the VFS holds s_umount for writing this results in a
deadlock.
We now do the dirty work by hand by submitting individual buffers. This
has the annoying "feature" that mounting can take a few seconds if the
journal is large as we have clear it all. One day someone should improve
on this by deferring the journal clearing to a helper kernel thread so it
can be done in the background but I don't have time for this at the moment
and the current solution works fine so I am leaving it like this for now.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ntfs/attrib.c')
| -rw-r--r-- | fs/ntfs/attrib.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index 1c08fefe487a..92dabdcf2b80 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -1,7 +1,7 @@ /** * attrib.c - NTFS attribute operations. Part of the Linux-NTFS project. * - * Copyright (c) 2001-2006 Anton Altaparmakov + * Copyright (c) 2001-2007 Anton Altaparmakov * Copyright (c) 2002 Richard Russon * * This program/include file is free software; you can redistribute it and/or @@ -2500,7 +2500,7 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val) struct page *page; u8 *kaddr; pgoff_t idx, end; - unsigned int start_ofs, end_ofs, size; + unsigned start_ofs, end_ofs, size; ntfs_debug("Entering for ofs 0x%llx, cnt 0x%llx, val 0x%hx.", (long long)ofs, (long long)cnt, val); @@ -2548,6 +2548,8 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val) kunmap_atomic(kaddr, KM_USER0); set_page_dirty(page); page_cache_release(page); + balance_dirty_pages_ratelimited(mapping); + cond_resched(); if (idx == end) goto done; idx++; @@ -2604,6 +2606,8 @@ int ntfs_attr_set(ntfs_inode *ni, const s64 ofs, const s64 cnt, const u8 val) kunmap_atomic(kaddr, KM_USER0); set_page_dirty(page); page_cache_release(page); + balance_dirty_pages_ratelimited(mapping); + cond_resched(); } done: ntfs_debug("Done."); |