15 Sep, 2009
1 commit
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* 'for-2.6.32' of git://git.kernel.dk/linux-2.6-block: (29 commits)
block: use blkdev_issue_discard in blk_ioctl_discard
Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads
block: don't assume device has a request list backing in nr_requests store
block: Optimal I/O limit wrapper
cfq: choose a new next_req when a request is dispatched
Seperate read and write statistics of in_flight requests
aoe: end barrier bios with EOPNOTSUPP
block: trace bio queueing trial only when it occurs
block: enable rq CPU completion affinity by default
cfq: fix the log message after dispatched a request
block: use printk_once
cciss: memory leak in cciss_init_one()
splice: update mtime and atime on files
block: make blk_iopoll_prep_sched() follow normal 0/1 return convention
cfq-iosched: get rid of must_alloc flag
block: use interrupts disabled version of raise_softirq_irqoff()
block: fix comment in blk-iopoll.c
block: adjust default budget for blk-iopoll
block: fix long lines in block/blk-iopoll.c
block: add blk-iopoll, a NAPI like approach for block devices
...
14 Sep, 2009
1 commit
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Introduce new function for generic inode syncing (vfs_fsync_range) and use
it from fsync() path. Introduce also new helper for syncing after a sync
write (generic_write_sync) using the generic function.Use these new helpers for syncing from generic VFS functions. This makes
O_SYNC writes to block devices acquire i_mutex for syncing. If we really
care about this, we can make block_fsync() drop the i_mutex and reacquire
it before it returns.CC: Evgeniy Polyakov
CC: ocfs2-devel@oss.oracle.com
CC: Joel Becker
CC: Felix Blyakher
CC: xfs@oss.sgi.com
CC: Anton Altaparmakov
CC: linux-ntfs-dev@lists.sourceforge.net
CC: OGAWA Hirofumi
CC: linux-ext4@vger.kernel.org
CC: tytso@mit.edu
Acked-by: Christoph Hellwig
Signed-off-by: Jan Kara
11 Sep, 2009
1 commit
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Splice should update the modification and access times on regular
files just like read and write. Not updating mtime will confuse
backup tools, etc...This patch only adds the time updates for regular files. For pipes
and other special files that splice touches the need for updating the
times is less clear. Let's discuss and fix that separately.Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe
19 May, 2009
1 commit
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Unfortunately multiple kmap() within a single thread are deadlockable,
so writing out multiple buffers with writev() isn't possible.Change the implementation so that it does a separate write() for each
buffer. This actually simplifies the code a lot since the
splice_from_pipe() helper can be used.This limitation is caused by HIGHMEM pages, and so only affects a
subset of architectures and configurations. In the future it may be
worth to implement default_file_splice_write() in a more efficient way
on configs that allow it.Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe
14 May, 2009
1 commit
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fs/splice.c: In function 'default_file_splice_read':
fs/splice.c:566: warning: 'error' may be used uninitialized in this functionwhich is sort-of true. The code will in fact return -ENOMEM instead of the
kernel_readv() return value.Cc: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe
13 May, 2009
1 commit
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We cannot reliably map more than one page at the time, or we risk
deadlocking. Just allocate the pages from low mem instead.Reported-by: Andrew Morton
Signed-off-by: Jens Axboe
11 May, 2009
3 commits
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If f_op->splice_write() is not implemented, fall back to a plain write.
Use vfs_writev() to write from the pipe buffers.This will allow splice on all filesystems and file types. This
includes "direct_io" files in fuse which bypass the page cache.Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe -
If f_op->splice_read() is not implemented, fall back to a plain read.
Use vfs_readv() to read into previously allocated pages.This will allow splice and functions using splice, such as the loop
device, to work on all filesystems. This includes "direct_io" files
in fuse which bypass the page cache.Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe -
Allow splice(2) to work when both the input and the output is a pipe.
Based on the impementation of the tee(2) syscall, but instead of
duplicating the buffer references move the buffers from the input pipe
to the output pipe.Moving the whole buffer only succeeds if the full length of the buffer
is spliced. Otherwise duplicate the buffer, just like tee(2), set the
length of the output buffer and advance the offset on the input
buffer.Since splice is operating on two pipes, special care needs to be taken
with locking to prevent AN ABBA deadlock. Again this is done
similarly to the tee(2) syscall, first preparing the input and output
pipes so there's data to consume and space for that data, and then
doing the move operation while holding both locks.If other processes are doing I/O on the same pipes parallel to the
splice, then by the time both inodes are locked there might be no
buffers left to move, or no space to move them to. In this case retry
the whole operation, including the preparation phase. This could lead
to starvation, but I'm not sure if that's serious enough to worry
about.Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe
17 Apr, 2009
1 commit
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splice: fix kernel-doc warnings
Warning(fs/splice.c:617): bad line:
Warning(fs/splice.c:722): No description found for parameter 'sd'
Warning(fs/splice.c:722): Excess function parameter 'pipe' description in 'splice_from_pipe_begin'Signed-off-by: Randy Dunlap
Signed-off-by: Linus Torvalds
15 Apr, 2009
6 commits
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There are lots of sequences like this, especially in splice code:
if (pipe->inode)
mutex_lock(&pipe->inode->i_mutex);
/* do something */
if (pipe->inode)
mutex_unlock(&pipe->inode->i_mutex);so introduce helpers which do the conditional locking and unlocking.
Also replace the inode_double_lock() call with a pipe_double_lock()
helper to avoid spreading the use of this functionality beyond the
pipe code.This patch is just a cleanup, and should cause no behavioral changes.
Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe -
Remove the now unused generic_file_splice_write_nolock() function.
It's conceptually broken anyway, because splice may need to wait for
pipe events so holding locks across the whole operation is wrong.Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe -
Rearrange locking of i_mutex on destination and call to
ocfs2_rw_lock() so locks are only held while buffers are copied with
the pipe_to_file() actor, and not while waiting for more data on the
pipe.Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe -
Rearrange locking of i_mutex on destination so it's only held while
buffers are copied with the pipe_to_file() actor, and not while
waiting for more data on the pipe.Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe -
splice_from_pipe() is only called from two places:
- generic_splice_sendpage()
- splice_write_null()Neither of these require i_mutex to be taken on the destination inode.
Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe -
Split up __splice_from_pipe() into four helper functions:
splice_from_pipe_begin()
splice_from_pipe_next()
splice_from_pipe_feed()
splice_from_pipe_end()splice_from_pipe_next() will wait (if necessary) for more buffers to
be added to the pipe. splice_from_pipe_feed() will feed the buffers
to the supplied actor and return when there's no more data available
(or if all of the requested data has been copied).This is necessary so that implementations can do locking around the
non-waiting splice_from_pipe_feed().This patch should not cause any change in behavior.
Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe
07 Apr, 2009
1 commit
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There's a possible deadlock in generic_file_splice_write(),
splice_from_pipe() and ocfs2_file_splice_write():- task A calls generic_file_splice_write()
- this calls inode_double_lock(), which locks i_mutex on both
pipe->inode and target inode
- ordering depends on inode pointers, can happen that pipe->inode is
locked first
- __splice_from_pipe() needs more data, calls pipe_wait()
- this releases lock on pipe->inode, goes to interruptible sleep
- task B calls generic_file_splice_write(), similarly to the first
- this locks pipe->inode, then tries to lock inode, but that is
already held by task A
- task A is interrupted, it tries to lock pipe->inode, but fails, as
it is already held by task B
- ABBA deadlockFix this by explicitly ordering locks: the outer lock must be on
target inode and the inner lock (which is later unlocked and relocked)
must be on pipe->inode. This is OK, pipe inodes and target inodes
form two nonoverlapping sets, generic_file_splice_write() and friends
are not called with a target which is a pipe.Signed-off-by: Miklos Szeredi
Acked-by: Mark Fasheh
Acked-by: Jens Axboe
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds
03 Apr, 2009
1 commit
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Recruit a page flag to aid in cache management. The following extra flag is
defined:(1) PG_fscache (PG_private_2)
The marked page is backed by a local cache and is pinning resources in the
cache driver.If PG_fscache is set, then things that checked for PG_private will now also
check for that. This includes things like truncation and page invalidation.
The function page_has_private() had been added to make the checks for both
PG_private and PG_private_2 at the same time.Signed-off-by: David Howells
Acked-by: Steve Dickson
Acked-by: Trond Myklebust
Acked-by: Rik van Riel
Acked-by: Al Viro
Tested-by: Daire Byrne
14 Jan, 2009
1 commit
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Signed-off-by: Heiko Carstens
09 Jan, 2009
1 commit
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A big patch for changing memcg's LRU semantics.
Now,
- page_cgroup is linked to mem_cgroup's its own LRU (per zone).- LRU of page_cgroup is not synchronous with global LRU.
- page and page_cgroup is one-to-one and statically allocated.
- To find page_cgroup is on what LRU, you have to check pc->mem_cgroup as
- lru = page_cgroup_zoneinfo(pc, nid_of_pc, zid_of_pc);- SwapCache is handled.
And, when we handle LRU list of page_cgroup, we do following.
pc = lookup_page_cgroup(page);
lock_page_cgroup(pc); .....................(1)
mz = page_cgroup_zoneinfo(pc);
spin_lock(&mz->lru_lock);
.....add to LRU
spin_unlock(&mz->lru_lock);
unlock_page_cgroup(pc);But (1) is spin_lock and we have to be afraid of dead-lock with zone->lru_lock.
So, trylock() is used at (1), now. Without (1), we can't trust "mz" is correct.This is a trial to remove this dirty nesting of locks.
This patch changes mz->lru_lock to be zone->lru_lock.
Then, above sequence will be written asspin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRU
mem_cgroup_add/remove/etc_lru() {
pc = lookup_page_cgroup(page);
mz = page_cgroup_zoneinfo(pc);
if (PageCgroupUsed(pc)) {
....add to LRU
}
spin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRUThis is much simpler.
(*) We're safe even if we don't take lock_page_cgroup(pc). Because..
1. When pc->mem_cgroup can be modified.
- at charge.
- at account_move().
2. at charge
the PCG_USED bit is not set before pc->mem_cgroup is fixed.
3. at account_move()
the page is isolated and not on LRU.Pros.
- easy for maintenance.
- memcg can make use of laziness of pagevec.
- we don't have to duplicated LRU/Active/Unevictable bit in page_cgroup.
- LRU status of memcg will be synchronized with global LRU's one.
- # of locks are reduced.
- account_move() is simplified very much.
Cons.
- may increase cost of LRU rotation.
(no impact if memcg is not configured.)Signed-off-by: KAMEZAWA Hiroyuki
Cc: Li Zefan
Cc: Balbir Singh
Cc: Pavel Emelyanov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
31 Oct, 2008
1 commit
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Nothing uses prepare_write or commit_write. Remove them from the tree
completely.[akpm@linux-foundation.org: schedule simple_prepare_write() for unexporting]
Signed-off-by: Nick Piggin
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Oct, 2008
1 commit
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This is debatable, but while we're debating it, let's disallow the
combination of splice and an O_APPEND destination.It's not entirely clear what the semantics of O_APPEND should be, and
POSIX apparently expects pwrite() to ignore O_APPEND, for example. So
we could make up any semantics we want, including the old ones.But Miklos convinced me that we should at least give it some thought,
and that accepting writes at arbitrary offsets is wrong at least for
IS_APPEND() files (which always have O_APPEND set, even if the reverse
isn't true: you can obviously have O_APPEND set on a regular file).So disallow O_APPEND entirely for now. I doubt anybody cares, and this
way we have one less gray area to worry about.Reported-and-argued-for-by: Miklos Szeredi
Acked-by: Jens Axboe
Signed-off-by: Linus Torvalds
05 Aug, 2008
1 commit
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Converting page lock to new locking bitops requires a change of page flag
operation naming, so we might as well convert it to something nicer
(!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked).This also facilitates lockdeping of page lock.
Signed-off-by: Nick Piggin
Acked-by: KOSAKI Motohiro
Acked-by: Peter Zijlstra
Acked-by: Andrew Morton
Acked-by: Benjamin Herrenschmidt
Signed-off-by: Linus Torvalds
27 Jul, 2008
2 commits
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All calls to remove_suid() are made with a file pointer, because
(similarly to file_update_time) it is called when the file is written.Clean up callers by passing in a file instead of a dentry.
Signed-off-by: Miklos Szeredi
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Use get_user_pages_fast in splice. This reverts some mmap_sem batching
there, however the biggest problem with mmap_sem tends to be hold times
blocking out other threads rather than cacheline bouncing. Further: on
architectures that implement get_user_pages_fast without locks, mmap_sem
can be avoided completely anyway.Signed-off-by: Nick Piggin
Cc: Dave Kleikamp
Cc: Andy Whitcroft
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Andi Kleen
Cc: Dave Kleikamp
Cc: Badari Pulavarty
Cc: Zach Brown
Cc: Jens Axboe
Reviewed-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jul, 2008
1 commit
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If a page was invalidated during splicing from file to a pipe, then
generic_file_splice_read() could return a short or zero count.This manifested itself in rare I/O errors seen on nfs exported fuse
filesystems. This is because nfsd uses splice_direct_to_actor() to read
files, and fuse uses invalidate_inode_pages2() to invalidate stale data on
open.Fix by redoing the page find/create if it was found to be truncated
(invalidated).Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Jens Axboe
28 May, 2008
2 commits
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splice currently assumes that try_to_release_page() always suceeds,
but it can return failure. If it does, we cannot steal the page.Acked-by: Mingming Cao
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Splice isn't always incrementing the ppos correctly, which broke
relay splice.Signed-off-by: Tom Zanussi
Tested-by: Dan Williams
Signed-off-by: Jens Axboe
08 May, 2008
1 commit
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This reverts commit c3270e577c18b3d0e984c3371493205a4807db9d.
07 May, 2008
1 commit
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generic_file_splice_write() duplicates remove_suid() just because it
doesn't hold i_mutex. But it grabs i_mutex inside splice_from_pipe()
anyway, so this is rather pointless.Move locking to generic_file_splice_write() and call remove_suid() and
__splice_from_pipe() instead.Signed-off-by: Miklos Szeredi
Signed-off-by: Jens Axboe
29 Apr, 2008
1 commit
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Splice isn't always incrementing the ppos correctly, which broke
relay splice.Signed-off-by: Tom Zanussi
Signed-off-by: Jens Axboe
10 Apr, 2008
1 commit
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There's a quirky loop in generic_file_splice_read() that could go
on indefinitely, if the file splice returns 0 permanently (and not
just as a temporary condition). Get rid of the loop and pass
back -EAGAIN correctly from __generic_file_splice_read(), so we
handle that condition properly as well.Signed-off-by: Jens Axboe
04 Apr, 2008
1 commit
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The loop block driver is careful to mask __GFP_IO|__GFP_FS out of its
mapping_gfp_mask, to avoid hangs under memory pressure. But nowadays
it uses splice, usually going through __generic_file_splice_read. That
must use mapping_gfp_mask instead of GFP_KERNEL to avoid those hangs.Signed-off-by: Hugh Dickins
Cc: Jens Axboe
Cc: Andrew Morton
Signed-off-by: Linus Torvalds
04 Mar, 2008
1 commit
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sys_tee() currently is a bit eager in returning -EAGAIN, it may do so
even if we don't have a chance of anymore data becoming available. So
improve the logic and only return -EAGAIN if we have an attached writer
to the input pipe.Reported by Johann Felix Soden and
Patrick McManus .Tested-by: Johann Felix Soden
Signed-off-by: Jens Axboe
11 Feb, 2008
1 commit
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Commit 8811930dc74a503415b35c4a79d14fb0b408a361 ("splice: missing user
pointer access verification") added the proper access_ok() calls to
copy_from_user_mmap_sem() which ensures we can copy the struct iovecs
from userspace to the kernel.But we also must check whether we can access the actual memory region
pointed to by the struct iovec to fix the access checks properly.Signed-off-by: Bastian Blank
Acked-by: Oliver Pinter
Cc: Jens Axboe
Cc: Andrew Morton
Signed-off-by: Pekka Enberg
Signed-off-by: Linus Torvalds
09 Feb, 2008
1 commit
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vmsplice_to_user() must always check the user pointer and length
with access_ok() before copying. Likewise, for the slow path of
copy_from_user_mmap_sem() we need to check that we may read from
the user region.Signed-off-by: Jens Axboe
Cc: Wojciech Purczynski
Signed-off-by: Greg Kroah-Hartman
Signed-off-by: Linus Torvalds
01 Feb, 2008
1 commit
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Andre Majorel points out that if we only updated
the atime when we transfer some data, we deviate from the standard
of always updating the atime. So change splice to always call
file_accessed() even if splice_direct_to_actor() didn't transfer
any data.Signed-off-by: Jens Axboe
30 Jan, 2008
1 commit
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A bug report on nfsd that states that since it was switched to use
splice instead of sendfile, the atime was no longer being updated
on the input file. do_generic_mapping_read() does this when accessing
the file, make splice do it for the direct splice handler.Signed-off-by: Jens Axboe
29 Jan, 2008
1 commit
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Allow caller to pass in a release function, there might be
other resources that need releasing as well. Needed for
network receive.Signed-off-by: Jens Axboe
Signed-off-by: David S. Miller
25 Jan, 2008
1 commit
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All instances of rw_verify_area() are followed by a call to
security_file_permission(), so just call the latter from the former.Acked-by: Eric Paris
Signed-off-by: James Morris
