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* tmpfs: clone shmem_file_splice_read()Hugh Dickins2011-07-25
| | | | | | | | | | | Copy __generic_file_splice_read() and generic_file_splice_read() from fs/splice.c to shmem_file_splice_read() in mm/shmem.c. Make page_cache_pipe_buf_ops and spd_release_page() accessible to it. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* splice: add wakeup_pipe_readers()Namhyung Kim2011-05-23
| | | | | | | | Add and use wakeup_pipe_readers() to consolidate duplicated codes. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2011-01-13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits) block: ensure that completion error gets properly traced blktrace: add missing probe argument to block_bio_complete block cfq: don't use atomic_t for cfq_group block cfq: don't use atomic_t for cfq_queue block: trace event block fix unassigned field block: add internal hd part table references block: fix accounting bug on cross partition merges kref: add kref_test_and_get bio-integrity: mark kintegrityd_wq highpri and CPU intensive block: make kblockd_workqueue smarter Revert "sd: implement sd_check_events()" block: Clean up exit_io_context() source code. Fix compile warnings due to missing removal of a 'ret' variable fs/block: type signature of major_to_index(int) to major_to_index(unsigned) block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p) cfq-iosched: don't check cfqg in choose_service_tree() fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors cdrom: export cdrom_check_events() sd: implement sd_check_events() sr: implement sr_check_events() ...
| * fs/splice: Pull buf->ops->confirm() from splice_from_pipe actorsMichał Mirosław2010-12-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch pulls calls to buf->ops->confirm() from all actors passed (also indirectly) to splice_from_pipe_feed(). Is avoiding the call to buf->ops->confirm() while splice()ing to /dev/null is an intentional optimization? No other user does that and this will remove this special case. Against current linux.git 6313e3c21743cc88bb5bd8aa72948ee1e83937b6. Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | Export 'get_pipe_info()' to other usersLinus Torvalds2010-11-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | And in particular, use it in 'pipe_fcntl()'. The other pipe functions do not need to use the 'careful' version, since they are only ever called for things that are already known to be pipes. The normal read/write/ioctl functions are called through the file operations structures, so if a file isn't a pipe, they'd never get called. But pipe_fcntl() is special, and called directly from the generic fcntl code, and needs to use the same careful function that the splice code is using. Cc: Jens Axboe <jaxboe@fusionio.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Rename 'pipe_info()' to 'get_pipe_info()'Linus Torvalds2010-11-28
|/ | | | | | | | | | | | | | | .. and change it to take the 'file' pointer instead of an inode, since that's what all users want anyway. The renaming is preparatory to exporting it to other users. The old 'pipe_info()' name was too generic and is already used elsewhere, so before making the function public we need to use a more specific name. Cc: Jens Axboe <jaxboe@fusionio.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* splice: fix misuse of SPLICE_F_NONBLOCKMiklos Szeredi2010-08-07
| | | | | | | | | | | | | | | | | | SPLICE_F_NONBLOCK is clearly documented to only affect blocking on the pipe. In __generic_file_splice_read(), however, it causes an EAGAIN if the page is currently being read. This makes it impossible to write an application that only wants failure if the pipe is full. For example if the same process is handling both ends of a pipe and isn't otherwise able to determine whether a splice to the pipe will fill it or not. We could make the read non-blocking on O_NONBLOCK or some other splice flag, but for now this is the simplest fix. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> CC: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* gcc-4.6: fs: fix unused but set warningsAndi Kleen2010-08-07
| | | | | | | | | | No real bugs I believe, just some dead code, and some shut up code. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* splice: check f_mode for seekable fileChangli Gao2010-06-30
| | | | | | | | | | | | | | check f_mode for seekable file As a seekable file is allowed without a llseek function, so the old way isn't work any more. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> ---- fs/splice.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* splice: direct_splice_actor() should not use pos in sdChangli Gao2010-06-30
| | | | | | | | | | | | direct_splice_actor() shouldn't use sd->pos, as sd->pos is for file reading, file->f_pos should be used instead. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> ---- fs/splice.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* fs/splice.c: fix mapping_gfp_mask usageNick Piggin2010-05-25
| | | | | | | | | | | | | | | | mapping_gfp_mask() is not supposed to store allocation contex details, only page location details. So mapping_gfp_mask should be applied to the pagecache page allocation, wheras normal (kernel mapped) memory should be used for surrounding allocations such as radix-tree nodes allocated by add_to_page_cache. Context modifiers should be applied on a per-callsite basis. So change splice to follow this convention (which is followed in similar code patterns in core code). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* pipe: add support for shrinking and growing pipesJens Axboe2010-05-21
| | | | | | | | | This patch adds F_GETPIPE_SZ and F_SETPIPE_SZ fcntl() actions for growing and shrinking the size of a pipe and adjusts pipe.c and splice.c (and relay and network splice) usage to work with these larger (or smaller) pipes. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* sendfile(): check f_op.splice_write() rather than f_op.sendpage()Changli Gao2009-11-04
| | | | | | | | | | | | sendfile(2) was reworked with the splice infrastructure, but it still checks f_op.sendpage() instead of f_op.splice_write() wrongly. Although if f_op.sendpage() exists, f_op.splice_write() always exists at the same time currently, the assumption will be broken in future silently. This patch also brings a side effect: sendfile(2) can work with any output file. Some security checks related to f_op are added too. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Merge branch 'for-2.6.32' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2009-09-14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * '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 ...
| * splice: update mtime and atime on filesMiklos Szeredi2009-09-11
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | vfs: Introduce new helpers for syncing after writing to O_SYNC file or ↵Jan Kara2009-09-14
|/ | | | | | | | | | | | | | | | | | | | | | | | | | IS_SYNC inode 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 <zbr@ioremap.net> CC: ocfs2-devel@oss.oracle.com CC: Joel Becker <joel.becker@oracle.com> CC: Felix Blyakher <felixb@sgi.com> CC: xfs@oss.sgi.com CC: Anton Altaparmakov <aia21@cantab.net> CC: linux-ntfs-dev@lists.sourceforge.net CC: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> CC: linux-ext4@vger.kernel.org CC: tytso@mit.edu Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* splice: fix kmaps in default_file_splice_write()Miklos Szeredi2009-05-19
| | | | | | | | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: fix error return codeAndrew Morton2009-05-14
| | | | | | | | | | | | fs/splice.c: In function 'default_file_splice_read': fs/splice.c:566: warning: 'error' may be used uninitialized in this function which is sort-of true. The code will in fact return -ENOMEM instead of the kernel_readv() return value. Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: fix repeated kmap()'s in default_file_splice_read()Jens Axboe2009-05-13
| | | | | | | | 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 <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: implement default splice_write methodMiklos Szeredi2009-05-11
| | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: implement default splice_read methodMiklos Szeredi2009-05-11
| | | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: implement pipe to pipe splicingMiklos Szeredi2009-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: fix new kernel-doc warningsRandy Dunlap2009-04-17
| | | | | | | | | | | 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 <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* splice: add helpers for locking pipe inodeMiklos Szeredi2009-04-15
| | | | | | | | | | | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: remove generic_file_splice_write_nolock()Miklos Szeredi2009-04-15
| | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* ocfs2: fix i_mutex locking in ocfs2_splice_to_file()Miklos Szeredi2009-04-15
| | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: fix i_mutex locking in generic_splice_write()Miklos Szeredi2009-04-15
| | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: remove i_mutex locking in splice_from_pipe()Miklos Szeredi2009-04-15
| | | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: split up __splice_from_pipe()Miklos Szeredi2009-04-15
| | | | | | | | | | | | | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: fix deadlock in splicing to fileMiklos Szeredi2009-04-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 deadlock Fix 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 <mszeredi@suse.cz> Acked-by: Mark Fasheh <mfasheh@suse.com> Acked-by: Jens Axboe <jens.axboe@oracle.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* FS-Cache: Recruit a page flags for cache managementDavid Howells2009-04-03
| | | | | | | | | | | | | | | | | | | | | | 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 <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
* [CVE-2009-0029] System call wrappers part 31Heiko Carstens2009-01-14
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* memcg: synchronized LRUKAMEZAWA Hiroyuki2009-01-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 as spin_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 LRU This 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 <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: remove prepare_write/commit_writeNick Piggin2008-10-30
| | | | | | | | | | | 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 <npiggin@suse.de> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Don't allow splice() to files opened with O_APPENDLinus Torvalds2008-10-09
| | | | | | | | | | | | | | | | | | | | | 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 <miklos@szeredi.hu> Acked-by: Jens Axboe <ens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: rename page trylockNick Piggin2008-08-05
| | | | | | | | | | | | | | | 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 <npiggin@suse.de> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [patch 3/5] vfs: change remove_suid() to file_remove_suid()Miklos Szeredi2008-07-26
| | | | | | | | | 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 <mszeredi@suse.cz>
* splice: use get_user_pages_fastNick Piggin2008-07-26
| | | | | | | | | | | | | | | | | | | | | | 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 <npiggin@suse.de> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: Jens Axboe <jens.axboe@oracle.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* splice: fix generic_file_splice_read() race with page invalidationMiklos Szeredi2008-07-04
| | | | | | | | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: handle try_to_release_page() failureJens Axboe2008-05-28
| | | | | | | | 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 <cmm@us.ibm.com Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: fix sendfile() issue with relayTom Zanussi2008-05-28
| | | | | | | | | Splice isn't always incrementing the ppos correctly, which broke relay splice. Signed-off-by: Tom Zanussi <zanussi@comcast.net> Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Revert "relay: fix splice problem"Jens Axboe2008-05-08
| | | | This reverts commit c3270e577c18b3d0e984c3371493205a4807db9d.
* vfs: splice remove_suid() cleanupMiklos Szeredi2008-05-07
| | | | | | | | | | | | 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 <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* relay: fix splice problemTom Zanussi2008-04-29
| | | | | | | | Splice isn't always incrementing the ppos correctly, which broke relay splice. Signed-off-by: Tom Zanussi <zanussi@comcast.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: fix infinite loop in generic_file_splice_read()Jens Axboe2008-04-10
| | | | | | | | | | 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 <jens.axboe@oracle.com>
* splice: use mapping_gfp_maskHugh Dickins2008-04-03
| | | | | | | | | | | | 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 <hugh@veritas.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* splice: only return -EAGAIN if there's hope of more dataJens Axboe2008-03-04
| | | | | | | | | | | | | 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 <johfel@gmx.de> and Patrick McManus <mcmanus@ducksong.com>. Tested-by: Johann Felix Soden <johfel@users.sourceforge.net> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: fix user pointer access in get_iovec_page_array()Bastian Blank2008-02-10
| | | | | | | | | | | | | | | | | 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 <waldi@debian.org> Acked-by: Oliver Pinter <oliver.pntr@gmail.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* splice: missing user pointer access verificationJens Axboe2008-02-08
| | | | | | | | | | | | 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 <jens.axboe@oracle.com> Cc: Wojciech Purczynski <cliph@research.coseinc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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