If block_read_full_page() detects an error when running get_block() it will
run SetPageError(), then it will zero out the block in pagecache and will mark
the buffer_head uptodate.
So at the end of readahead we end up with a non-uptodate pagecache page which
is marked PageError. But it has uptodate buffers.
The pagefault code will run ClearPageError, will launch readpage a second time
and block_read_full_page() will notice the uptodate buffers and will mark the
page uptodate as well. We end up with an uptodate, !PageError page full of
zeros and the error is lost.
(It seems a little odd that filemap_nopage() runs ClearPageError(). I guess
all of this adds up to meaning that for each attempted access to the page, the
pagefault handler will retry the I/O. Which is good and bad. If the app is
ignoring SIGBUS for some reason we could get a lot of back-to-back I/O
errors.)
Fix it by not marking the pagecache buffer_head as uptodate if the attempt to
map that buffer to a disk block failed.
Credit-to: Qu Fuping <fs@ercist.iscas.ac.cn>
For reporting the bug and identifying its source.
Signed-off-by: Qu Fuping <fs@ercist.iscas.ac.cn>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
VmallocTotal: 34359738367 kB
VmallocUsed: 266288 kB
VmallocChunk: 18014366299193295 kB
is unsettling - x86_64 and some other architectures keep a separate address
range for modules in vmalloc's vmlist, which /proc/meminfo should pass over.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kfree() can handle a NULL pointer, don't worry about passing it one.
Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
This change from March 3rd causes the partition parsing code to ignore
partitions which have a signature byte of zero. Turns out that more people
have such partitions than we expected, and their device numbering is coming up
wrong in post-2.6.11 kernels.
So revert the change while we think about the problem a bit more.
Cc: Andries Brouwer <Andries.Brouwer@cwi.nl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This may be the cause of several open PV's of incorrect
delay flags being set and then tripping asserts.
Do not return a delay alloc extent when the caller is asking to do a write.
SGI Modid: xfs-linux:xfs-kern:189616a
Signed-off-by: Russell Cattelan <cattelan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@sgi.com>
This patch fixes an off by one error found by the Coverity checker.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add some comments about task->comm, to explain what it is near its definition
and provide some important pointers to its uses.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use NULL instead of 0 for pointer (sparse warning):
fs/reiserfs/namei.c:611:50: warning: Using plain integer as NULL pointer
Signed-off-by: Randy Dunlap <rddunlap@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes some needlessly global identifiers static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Arjan van de Ven <arjanv@infradead.org>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This had a fatal lock ranking bug: we do journal_start outside
mpage_writepages()'s lock_page().
Revert the whole thing, think again.
Credit-to: Jan Kara <jack@suse.cz>
For identifying the bug.
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The only caller that ever sets it can call fsync_bdev itself easily. Also
update some comments.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There's no longer a reason to document the obsolete BK usage.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The `last_bh' logic probably isn't worth much. In those situations where only
the front part of the page is being written out we will save some looping but
in the vastly more common case of an all-page writeout if just adds more code.
Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove all those get_bh()'s and put_bh()'s by extending lock_page() to cover
the troublesome regions.
(get_bh() and put_bh() happen every time whereas contention on a page's lock
in there happens basically never).
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When running
fsstress -v -d $DIR/tmp -n 1000 -p 1000 -l 2
on an ext2 filesystem with 1024 byte block size, on SMP i386 with 4096 byte
page size over loopback to an image file on a tmpfs filesystem, I would
very quickly hit
BUG_ON(!buffer_async_write(bh));
in fs/buffer.c:end_buffer_async_write
It seems that more than one request would be submitted for a given bh
at a time.
What would happen is the following:
2 threads doing __mpage_writepages on the same page.
Thread 1 - lock the page first, and enter __block_write_full_page.
Thread 1 - (eg.) mark_buffer_async_write on the first 2 buffers.
Thread 1 - set page writeback, unlock page.
Thread 2 - lock page, wait on page writeback
Thread 1 - submit_bh on the first 2 buffers.
=> both requests complete, none of the page buffers are async_write,
end_page_writeback is called.
Thread 2 - wakes up. enters __block_write_full_page.
Thread 2 - mark_buffer_async_write on (eg.) the last buffer
Thread 1 - finds the last buffer has async_write set, submit_bh on that.
Thread 2 - submit_bh on the last buffer.
=> oops.
So change __block_write_full_page to explicitly keep track of the last bh
we need to issue, so we don't touch anything after issuing the last
request.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix a race where __block_prepare_write can leak out an in-flight read
against a bh if get_block returns an error. This can lead to the page
becoming unlocked while the buffer is locked and the read still in flight.
__mpage_writepage BUGs on this condition.
BUG sighted on a 2-way Itanium2 system with 16K PAGE_SIZE running
fsstress -v -d $DIR/tmp -n 1000 -p 1000 -l 2
where $DIR is a new ext2 filesystem with 4K blocks that is quite
small (causing get_block to fail often with -ENOSPC).
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This cleans up the error handling and fixes a crash if a hostfs mount fails.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This makes sure that reclaimable buffer headers and reclaimable inodes
are accounted properly during the overcommit checks.
Signed-off-by: Andrea Arcangeli <andrea@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
handling for unwritten extents can be moved out of interrupt context.
SGI Modid: xfs-linux:xfs-kern:22343a
Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Christoph Hellwig <hch@sgi.com>
Thus, relax the checking in fs/ntfs/super.c::is_boot_sector_ntfs() to
only emit a warning when the checksum is incorrect rather than
refusing the mount. Thanks to Bernd Casimir for pointing this
problem out.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
- Add ifdef NTFS_RW around write specific code if fs/ntfs/runlist.[hc] and
fs/ntfs/attrib.[hc].
- Minor bugfix to fs/ntfs/attrib.c::ntfs_attr_make_non_resident() where the
runlist was not freed in all error cases.
- Add fs/ntfs/runlist.[hc]::ntfs_rl_find_vcn_nolock().
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
and handle the case where an attribute is converted from resident
to non-resident by a concurrent file write.
- Reorder some operations when converting an attribute from resident
to non-resident (fs/ntfs/attrib.c) so it is safe wrt concurrent
->readpage and ->writepage.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
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>
