- 04 1月, 2012 1 次提交
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由 Al Viro 提交于
Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: NNick Piggin <npiggin@suse.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 01 11月, 2011 1 次提交
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由 Tao Ma 提交于
On the ext4 mailing list[1], we got some report about errors in __find_get_block_slow(), but the information is very limited. If the device information is given, we can know the name of the sick volume. Futhermore, we can get the corresponding status of that block(group, inode block etc) by analyzing the disk layout. [1] http://marc.info/?l=linux-ext4&m=131379831421147&w=2Signed-off-by: NTao Ma <boyu.mt@taobao.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 31 10月, 2011 1 次提交
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由 Curt Wohlgemuth 提交于
This creates a new 'reason' field in a wb_writeback_work structure, which unambiguously identifies who initiates writeback activity. A 'wb_reason' enumeration has been added to writeback.h, to enumerate the possible reasons. The 'writeback_work_class' and tracepoint event class and 'writeback_queue_io' tracepoints are updated to include the symbolic 'reason' in all trace events. And the 'writeback_inodes_sbXXX' family of routines has had a wb_stats parameter added to them, so callers can specify why writeback is being started. Acked-by: NJan Kara <jack@suse.cz> Signed-off-by: NCurt Wohlgemuth <curtw@google.com> Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
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- 28 10月, 2011 1 次提交
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由 Wang Sheng-Hui 提交于
The patch is aganist 3.1-rc3. Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com> Signed-off-by: NChristoph Hellwig <hch@lst.de>
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- 16 6月, 2011 1 次提交
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由 Jan Kara 提交于
I've got a report of a file corruption from fsxlinux on ext3. The important operations to the page were: mapwrite to a hole partial write to the page read - found the page zeroed from the end of the normal write The culprit seems to be that if get_block() fails in __block_write_begin() (e.g. transient ENOSPC in ext3), the function does ClearPageUptodate(page). Thus when we retry the write, the logic in __block_write_begin() thinks zeroing of the page is needed and overwrites old data. In fact, I don't see why we should ever need to zero the uptodate bit here - either the page was uptodate when we entered __block_write_begin() and it should stay so when we leave it, or it was not uptodate and noone had right to set it uptodate during __block_write_begin() so it remains !uptodate when we leave as well. So just remove clearing of the bit. Signed-off-by: NJan Kara <jack@suse.cz> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 28 5月, 2011 1 次提交
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由 Darrick J. Wong 提交于
For filesystems such as nilfs2 and xfs that use block_page_mkwrite, modify that function to wait for pending writeback before allowing the page to become writable. This is needed to stabilize pages during writeback for those two filesystems. Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 27 5月, 2011 1 次提交
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由 Dan Magenheimer 提交于
This fourth patch of eight in this cleancache series provides the core hooks in VFS for: initializing cleancache per filesystem; capturing clean pages reclaimed by page cache; attempting to get pages from cleancache before filesystem read; and ensuring coherency between pagecache, disk, and cleancache. Note that the placement of these hooks was stable from 2.6.18 to 2.6.38; a minor semantic change was required due to a patchset in 2.6.39. All hooks become no-ops if CONFIG_CLEANCACHE is unset, or become a check of a boolean global if CONFIG_CLEANCACHE is set but no cleancache "backend" has claimed cleancache_ops. Details and a FAQ can be found in Documentation/vm/cleancache.txt [v8: minchan.kim@gmail.com: adapt to new remove_from_page_cache function] Signed-off-by: NChris Mason <chris.mason@oracle.com> Signed-off-by: NDan Magenheimer <dan.magenheimer@oracle.com> Reviewed-by: NJeremy Fitzhardinge <jeremy@goop.org> Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rik Van Riel <riel@redhat.com> Cc: Jan Beulich <JBeulich@novell.com> Cc: Andreas Dilger <adilger@sun.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Nitin Gupta <ngupta@vflare.org>
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- 26 5月, 2011 2 次提交
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由 Jan Kara 提交于
We should not allow file modification via mmap while the filesystem is frozen. So block in block_page_mkwrite() while the filesystem is frozen. We cannot do the blocking wait in __block_page_mkwrite() since e.g. ext4 will want to call that function with transaction started in some cases and that would deadlock. But we can at least do the non-blocking reliable check in __block_page_mkwrite() which is the hardest part anyway. We have to check for frozen filesystem with the page marked dirty and under page lock with which we then return from ->page_mkwrite(). Only that way we cannot race with writeback done by freezing code - either we mark the page dirty after the writeback has started, see freezing in progress and block, or writeback will wait for our page lock which is released only when the fault is done and then writeback will writeout and writeprotect the page again. Reviewed-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJan Kara <jack@suse.cz> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Jan Kara 提交于
Create __block_page_mkwrite() helper which does all what block_page_mkwrite() does except that it passes back errors from __block_write_begin / block_commit_write calls. Reviewed-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJan Kara <jack@suse.cz> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 25 3月, 2011 1 次提交
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由 Dave Chinner 提交于
Protect inode state transitions and validity checks with the inode->i_lock. This enables us to make inode state transitions independently of the inode_lock and is the first step to peeling away the inode_lock from the code. This requires that __iget() is done atomically with i_state checks during list traversals so that we don't race with another thread marking the inode I_FREEING between the state check and grabbing the reference. Also remove the unlock_new_inode() memory barrier optimisation required to avoid taking the inode_lock when clearing I_NEW. Simplify the code by simply taking the inode->i_lock around the state change and wakeup. Because the wakeup is no longer tricky, remove the wake_up_inode() function and open code the wakeup where necessary. Signed-off-by: NDave Chinner <dchinner@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 17 3月, 2011 1 次提交
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由 Jens Axboe 提交于
It used WRITE_SYNC_PLUG before and potentially submits a batch of IO, so lets enable plugging for this case. Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
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- 10 3月, 2011 2 次提交
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由 Jens Axboe 提交于
With the plugging now being explicitly controlled by the submitter, callers need not pass down unplugging hints to the block layer. If they want to unplug, it's because they manually plugged on their own - in which case, they should just unplug at will. Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
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由 Jens Axboe 提交于
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
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- 17 12月, 2010 2 次提交
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由 Christoph Lameter 提交于
__this_cpu_inc can create a single instruction with the same effect as the _get_cpu_var(..)++ construct in buffer.c. Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Christoph Hellwig <hch@lst.de> Acked-by: NH. Peter Anvin <hpa@zytor.com> Signed-off-by: NChristoph Lameter <cl@linux.com> Signed-off-by: NTejun Heo <tj@kernel.org>
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由 Christoph Lameter 提交于
Optimize various per cpu area operations through these new percpu operations. These operations avoid address calculations through the use of segment prefixes and multiple memory references through RMW instructions etc. Reduces code size: Before: christoph@linux-2.6$ size fs/buffer.o text data bss dec hex filename 19169 80 28 19277 4b4d fs/buffer.o After: christoph@linux-2.6$ size fs/buffer.o text data bss dec hex filename 19138 80 28 19246 4b2e fs/buffer.o V3->V4: - Move the use of this_cpu_inc_return into a later patch so that this one can go in without percpu infrastructure changes. Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Christoph Hellwig <hch@lst.de> Acked-by: NH. Peter Anvin <hpa@zytor.com> Signed-off-by: NChristoph Lameter <cl@linux.com> Signed-off-by: NTejun Heo <tj@kernel.org>
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- 27 10月, 2010 2 次提交
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由 Namhyung Kim 提交于
bh->b_private is initialized within init_buffer(), thus this assignment is redundant. Signed-off-by: NNamhyung Kim <namhyung@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Wu Fengguang 提交于
This removes more dead code that was somehow missed by commit 0d99519e (writeback: remove unused nonblocking and congestion checks). There are no behavior change except for the removal of two entries from one of the ext4 tracing interface. The nonblocking checks in ->writepages are no longer used because the flusher now prefer to block on get_request_wait() than to skip inodes on IO congestion. The latter will lead to more seeky IO. The nonblocking checks in ->writepage are no longer used because it's redundant with the WB_SYNC_NONE check. We no long set ->nonblocking in VM page out and page migration, because a) it's effectively redundant with WB_SYNC_NONE in current code b) it's old semantic of "Don't get stuck on request queues" is mis-behavior: that would skip some dirty inodes on congestion and page out others, which is unfair in terms of LRU age. Inspired by Christoph Hellwig. Thanks! Signed-off-by: NWu Fengguang <fengguang.wu@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: David Howells <dhowells@redhat.com> Cc: Sage Weil <sage@newdream.net> Cc: Steve French <sfrench@samba.org> Cc: Chris Mason <chris.mason@oracle.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 26 10月, 2010 3 次提交
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由 Namhyung Kim 提交于
If we have the appropriate page already, call __block_write_begin() directly instead of releasing and regrabbing it inside of block_write_begin(). Signed-off-by: NNamhyung Kim <namhyung@gmail.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Namhyung Kim 提交于
bh->b_private is initialized within init_buffer(), thus the assignment should be redundant. Remove it. Signed-off-by: NNamhyung Kim <namhyung@gmail.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Christoph Hellwig 提交于
__block_write_begin and block_prepare_write are identical except for slightly different calling conventions. Convert all callers to the __block_write_begin calling conventions and drop block_prepare_write. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 10 9月, 2010 1 次提交
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由 Christoph Hellwig 提交于
This flag was only set for barrier buffers, which we don't submit anymore. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
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- 18 8月, 2010 2 次提交
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由 Christoph Hellwig 提交于
These flags aren't real I/O types, but tell ll_rw_block to always lock the buffer instead of giving up on a failed trylock. Instead add a new write_dirty_buffer helper that implements this semantic and use it from the existing SWRITE* callers. Note that the ll_rw_block code had a bug where it didn't promote WRITE_SYNC_PLUG properly, which this patch fixes. In the ufs code clean up the helper that used to call ll_rw_block to mirror sync_dirty_buffer, which is the function it implements for compound buffers. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Christoph Hellwig 提交于
Instead of abusing a buffer_head flag just add a variant of sync_dirty_buffer which allows passing the exact type of write flag required. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 10 8月, 2010 4 次提交
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由 Christoph Hellwig 提交于
Move the call to vmtruncate to get rid of accessive blocks to the callers in preparation of the new truncate sequence and rename the non-truncating version to block_write_begin. While we're at it also remove several unused arguments to block_write_begin. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Christoph Hellwig 提交于
Split up the block_write_begin implementation - __block_write_begin is a new trivial wrapper for block_prepare_write that always takes an already allocated page and can be either called from block_write_begin or filesystem code that already has a page allocated. Remove the handling of already allocated pages from block_write_begin after switching all callers that do it to __block_write_begin. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Christoph Hellwig 提交于
Move the call to vmtruncate to get rid of accessive blocks to the callers in preparation of the new truncate sequence and rename the non-truncating version to cont_write_begin. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Christoph Hellwig 提交于
Move the call to vmtruncate to get rid of accessive blocks to the only remaining caller and rename the non-truncating version to nobh_write_begin. Get rid of the superflous file argument to it while we're at it. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 28 5月, 2010 1 次提交
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由 npiggin@suse.de 提交于
Introduce a new truncate calling sequence into fs/mm subsystems. Rather than setattr > vmtruncate > truncate, have filesystems call their truncate sequence from ->setattr if filesystem specific operations are required. vmtruncate is deprecated, and truncate_pagecache and inode_newsize_ok helpers introduced previously should be used. simple_setattr is introduced for simple in-ram filesystems to implement the new truncate sequence. Eventually all filesystems should be converted to implement a setattr, and the default code in notify_change should go away. simple_setsize is also introduced to perform just the ATTR_SIZE portion of simple_setattr (ie. changing i_size and trimming pagecache). To implement the new truncate sequence: - filesystem specific manipulations (eg freeing blocks) must be done in the setattr method rather than ->truncate. - vmtruncate can not be used by core code to trim blocks past i_size in the event of write failure after allocation, so this must be performed in the fs code. - convert usage of helpers block_write_begin, nobh_write_begin, cont_write_begin, and *blockdev_direct_IO* to use _newtrunc postfixed variants. These avoid calling vmtruncate to trim blocks (see previous). - inode_setattr should not be used. generic_setattr is a new function to be used to copy simple attributes into the generic inode. - make use of the better opportunity to handle errors with the new sequence. Big problem with the previous calling sequence: the filesystem is not called until i_size has already changed. This means it is not allowed to fail the call, and also it does not know what the previous i_size was. Also, generic code calling vmtruncate to truncate allocated blocks in case of error had no good way to return a meaningful error (or, for example, atomically handle block deallocation). Cc: Christoph Hellwig <hch@lst.de> Acked-by: NJan Kara <jack@suse.cz> Signed-off-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 22 5月, 2010 4 次提交
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由 Al Viro 提交于
... and switch the simple "loop over superblocks and do something" loops to it. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
We used to remove from s_list and s_instances at the same time. So let's *not* do the former and skip superblocks that have empty s_instances in the loops over s_list. The next step, of course, will be to get rid of rescan logics in those loops. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Tejun Heo 提交于
invalidate_bdev() should release all page cache pages which are clean and not being used; however, if some pages are still in the percpu LRU add caches on other cpus, those pages are considered in used and don't get released. Fix it by calling lru_add_drain_all() before trying to invalidate pages. This problem was discovered while testing block automatic native capacity unlocking. Null pages which were read before automatic unlocking didn't get released by invalidate_bdev() and ended up interfering with partition scan after unlocking. Signed-off-by: NTejun Heo <tj@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
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- 13 3月, 2010 1 次提交
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由 Richard Kennedy 提交于
When using slub, having a kmem_cache constructor forces slub to add a free pointer to the size of the cached object, which can have a significant impact to the number of small objects that can fit into a slab. As buffer_head is relatively small and we can have large numbers of them, removing the constructor is a definite win. On x86_64 removing the constructor gives me 39 objects/slab, 3 more than without the patch. And on x86_32 73 objects/slab, which is 9 more. As alloc_buffer_head() already initializes each new object there is very little difference in actual code run. Signed-off-by: NRichard Kennedy <richard@rsk.demon.co.uk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <jens.axboe@oracle.com> Acked-by: NNick Piggin <npiggin@suse.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: NRik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 04 2月, 2010 1 次提交
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由 Adam Buchbinder 提交于
Some comments misspell "invocation"; this fixes them. No code changes. Signed-off-by: NAdam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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- 26 9月, 2009 1 次提交
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由 Jens Axboe 提交于
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
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- 24 9月, 2009 1 次提交
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由 npiggin@suse.de 提交于
Update some fs code to make use of new helper functions introduced in the previous patch. Should be no significant change in behaviour (except CIFS now calls send_sig under i_lock, via inode_newsize_ok). Reviewed-by: NChristoph Hellwig <hch@lst.de> Acked-by: NMiklos Szeredi <miklos@szeredi.hu> Cc: linux-nfs@vger.kernel.org Cc: Trond.Myklebust@netapp.com Cc: linux-cifs-client@lists.samba.org Cc: sfrench@samba.org Signed-off-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 23 9月, 2009 1 次提交
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由 H Hartley Sweeten 提交于
According to Documentation/CodingStyle the EXPORT* macro should follow immediately after the closing function brace line. Also, mark_buffer_async_write_endio() and do_thaw_all() are not used elsewhere so they should be marked as static. In addition, file_fsync() is actually in fs/sync.c so move the EXPORT* to that file. Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 11 9月, 2009 1 次提交
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由 Jens Axboe 提交于
This gets rid of pdflush for bdi writeout and kupdated style cleaning. pdflush writeout suffers from lack of locality and also requires more threads to handle the same workload, since it has to work in a non-blocking fashion against each queue. This also introduces lumpy behaviour and potential request starvation, since pdflush can be starved for queue access if others are accessing it. A sample ffsb workload that does random writes to files is about 8% faster here on a simple SATA drive during the benchmark phase. File layout also seems a LOT more smooth in vmstat: r b swpd free buff cache si so bi bo in cs us sy id wa 0 1 0 608848 2652 375372 0 0 0 71024 604 24 1 10 48 42 0 1 0 549644 2712 433736 0 0 0 60692 505 27 1 8 48 44 1 0 0 476928 2784 505192 0 0 4 29540 553 24 0 9 53 37 0 1 0 457972 2808 524008 0 0 0 54876 331 16 0 4 38 58 0 1 0 366128 2928 614284 0 0 4 92168 710 58 0 13 53 34 0 1 0 295092 3000 684140 0 0 0 62924 572 23 0 9 53 37 0 1 0 236592 3064 741704 0 0 4 58256 523 17 0 8 48 44 0 1 0 165608 3132 811464 0 0 0 57460 560 21 0 8 54 38 0 1 0 102952 3200 873164 0 0 4 74748 540 29 1 10 48 41 0 1 0 48604 3252 926472 0 0 0 53248 469 29 0 7 47 45 where vanilla tends to fluctuate a lot in the creation phase: r b swpd free buff cache si so bi bo in cs us sy id wa 1 1 0 678716 5792 303380 0 0 0 74064 565 50 1 11 52 36 1 0 0 662488 5864 319396 0 0 4 352 302 329 0 2 47 51 0 1 0 599312 5924 381468 0 0 0 78164 516 55 0 9 51 40 0 1 0 519952 6008 459516 0 0 4 78156 622 56 1 11 52 37 1 1 0 436640 6092 541632 0 0 0 82244 622 54 0 11 48 41 0 1 0 436640 6092 541660 0 0 0 8 152 39 0 0 51 49 0 1 0 332224 6200 644252 0 0 4 102800 728 46 1 13 49 36 1 0 0 274492 6260 701056 0 0 4 12328 459 49 0 7 50 43 0 1 0 211220 6324 763356 0 0 0 106940 515 37 1 10 51 39 1 0 0 160412 6376 813468 0 0 0 8224 415 43 0 6 49 45 1 1 0 85980 6452 886556 0 0 4 113516 575 39 1 11 54 34 0 2 0 85968 6452 886620 0 0 0 1640 158 211 0 0 46 54 A 10 disk test with btrfs performs 26% faster with per-bdi flushing. A SSD based writeback test on XFS performs over 20% better as well, with the throughput being very stable around 1GB/sec, where pdflush only manages 750MB/sec and fluctuates wildly while doing so. Random buffered writes to many files behave a lot better as well, as does random mmap'ed writes. A separate thread is added to sync the super blocks. In the long term, adding sync_supers_bdi() functionality could get rid of this thread again. Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
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- 22 8月, 2009 1 次提交
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由 Linus Torvalds 提交于
In commit a8e7d49a ("Fix race in create_empty_buffers() vs __set_page_dirty_buffers()"), I removed a test for a NULL page mapping unintentionally when some of the code inside __set_page_dirty() was moved to the callers. That removal generally didn't matter, since a filesystem would serialize truncation (which clears the page mapping) against writing (which marks the buffer dirty), so locking at a higher level (either per-page or an inode at a time) should mean that the buffer page would be stable. And indeed, nothing bad seemed to happen. Except it turns out that apparently reiserfs does something odd when under load and writing out the journal, and we have a number of bugzilla entries that look similar: http://bugzilla.kernel.org/show_bug.cgi?id=13556 http://bugzilla.kernel.org/show_bug.cgi?id=13756 http://bugzilla.kernel.org/show_bug.cgi?id=13876 and it looks like reiserfs depended on that check (the common theme seems to be "data=journal", and a journal writeback during a truncate). I suspect reiserfs should have some additional locking, but in the meantime this should get us back to the pre-2.6.29 behavior. Pattern-pointed-out-by: NRoland Kletzing <devzero@web.de> Cc: stable@kernel.org (2.6.29 and 2.6.30) Cc: Jeff Mahoney <jeffm@suse.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 06 6月, 2009 1 次提交
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由 Theodore Ts'o 提交于
The nobh_truncate_page() function is used by ext2, exofs, and jfs. Of these three, only ext2 and jfs's get_block() function pays attention to bh->b_size --- which is normally always the filesystem blocksize except when the get_block() function is called by either mpage_readpage(), mpage_readpages(), or the direct I/O routines in fs/direct_io.c. Unfortunately, nobh_truncate_page() does not initialize map_bh before calling the filesystem-supplied get_block() function. So ext2 and jfs will try to calculate the number of blocks to map by taking stack garbage and shifting it left by inode->i_blkbits. This should be *mostly* harmless (except the filesystem will do some unnneeded work) unless the stack garbage is less than filesystem's blocksize, in which case maxblocks will be zero, and the attempt to find out whether or not the filesystem has a hole at a given logical block will fail, and the page cache entry might not get zero'ed out. Also if the stack garbage in in map_bh->state happens to have the BH_Mapped bit set, there could be an attempt to call readpage() on a non-existent page, which could cause nobh_truncate_page() to return an error when it should not. Fix this by initializing map_bh->state and map_bh->size. Fortunately, it's probably fairly unlikely that ext2 and jfs users mount with nobh these days. Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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