linux/fs
Miklos Szeredi ce534fb052 fuse: allow splice to move pages
When splicing buffers to the fuse device with SPLICE_F_MOVE, try to
move pages from the pipe buffer into the page cache.  This allows
populating the fuse filesystem's cache without ever touching the page
contents, i.e. zero copy read capability.

The following steps are performed when trying to move a page into the
page cache:

 - buf->ops->confirm() to make sure the new page is uptodate
 - buf->ops->steal() to try to remove the new page from it's previous place
 - remove_from_page_cache() on the old page
 - add_to_page_cache_locked() on the new page

If any of the above steps fail (non fatally) then the code falls back
to copying the page.  In particular ->steal() will fail if there are
external references (other than the page cache and the pipe buffer) to
the page.

Also since the remove_from_page_cache() + add_to_page_cache_locked()
are non-atomic it is possible that the page cache is repopulated in
between the two and add_to_page_cache_locked() will fail.  This could
be fixed by creating a new atomic replace_page_cache_page() function.

fuse_readpages_end() needed to be reworked so it works even if
page->mapping is NULL for some or all pages which can happen if the
add_to_page_cache_locked() failed.

A number of sanity checks were added to make sure the stolen pages
don't have weird flags set, etc...  These could be moved into generic
splice/steal code.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2010-05-25 15:06:07 +02:00
..
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs 2010-05-24 07:41:13 -07:00
adfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
affs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
afs AFS: Don't put struct file on the stack 2010-05-21 18:31:28 -04:00
autofs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
autofs4 autofs4: Pushdown the bkl from ioctl 2010-05-22 17:44:18 +02:00
befs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
bfs bfs: replace inode uid,gid,mode initialization with helper function 2010-05-21 18:31:25 -04:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
cachefiles CacheFiles: Fix error handling in cachefiles_determine_cache_security() 2010-05-12 18:23:58 -07:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2010-05-24 07:37:52 -07:00
cifs cifs: fix noserverino handling when unix extensions are enabled 2010-05-17 20:59:21 +00:00
coda Merge branch 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing 2010-05-24 08:01:10 -07:00
configfs Fix the regression created by "set S_DEAD on unlink()..." commit 2010-05-15 07:16:33 -04:00
cramfs
debugfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
devpts Simplify devpts_get_sb() failure exits 2010-05-21 18:31:12 -04:00
dlm dlm: fix ast ordering for user locks 2010-04-30 14:52:51 -05:00
ecryptfs switch ecryptfs_write() to struct inode *, kill on-stack fake files 2010-05-21 18:31:28 -04:00
efs
exofs Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd 2010-05-24 07:57:41 -07:00
exportfs nfs: new subdir Documentation/filesystems/nfs 2009-10-27 19:34:04 -04:00
ext2 ext2: replace inode uid,gid,mode init with helper 2010-05-21 18:31:24 -04:00
ext3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
fat Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6 2010-05-24 07:41:47 -07:00
freevxfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fscache fs-cache: order the debugfs stats correctly 2010-04-07 08:38:05 -07:00
fuse fuse: allow splice to move pages 2010-05-25 15:06:07 +02:00
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
hfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hfsplus hfsplus: Push down BKL into ioctl function 2010-05-17 05:27:03 +02:00
hostfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hpfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
hppfs hppfs can use existing proc_mnt, no need for do_kern_mount() in there 2010-03-03 14:08:00 -05:00
hugetlbfs Untangling ima mess, part 1: alloc_file() 2009-12-16 12:16:47 -05:00
isofs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
jbd ext3: Fix waiting on transaction during fsync 2010-05-21 19:30:41 +02:00
jbd2 Merge branch 'master' into for-2.6.35 2010-05-21 21:27:26 +02:00
jffs2 jffs2: constify xattr_handler 2010-05-21 18:31:20 -04:00
jfs jfs: replace inode uid,gid,mode init with helper 2010-05-21 18:31:23 -04:00
lockd include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
logfs logfs: replace inode uid,gid,mode initialization with helper function 2010-05-21 18:31:27 -04:00
minix minix: replace inode uid,gid,mode init with helper 2010-05-21 18:31:24 -04:00
ncpfs ncpfs: BKL ioctl pushdown 2010-05-17 05:27:42 +02:00
nfs NFS: Don't call iput() in nfs_access_cache_shrinker 2010-05-14 15:09:36 -04:00
nfs_common include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
nfsd sanitize vfs_fsync calling conventions 2010-05-21 18:31:21 -04:00
nilfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
nls Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6 2009-09-30 09:31:14 -07:00
notify Saner locking around deactivate_super() 2010-05-21 18:31:14 -04:00
ntfs include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
ocfs2 ocfs2: replace inode uid,gid,mode initialization with helper function 2010-05-21 18:31:25 -04:00
omfs omfs: replace inode uid,gid,mode initialization with helper function 2010-05-21 18:31:25 -04:00
openpromfs
partitions Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
proc Merge branch 'bkl/procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing 2010-05-19 17:23:28 -07:00
qnx4 fs/qnx4: decrement sizeof size in strncmp 2010-02-04 11:55:46 +01:00
quota new helper: iterate_supers() 2010-05-21 18:31:16 -04:00
ramfs ramfs: replace inode uid,gid,mode initialization with helper function 2010-05-21 18:31:26 -04:00
reiserfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
romfs fix leak in romfs_fill_super() 2010-01-26 22:22:26 -05:00
smbfs smbfs: Push down BKL into ioctl function 2010-05-17 05:27:04 +02:00
squashfs squashfs: fix potential buffer over-run on 4K block file systems 2010-04-25 02:09:05 +01:00
sysfs sysfs: add struct file* to bin_attr callbacks 2010-05-21 09:37:31 -07:00
sysv sysv: replace inode uid,gid,mode initialization with helper function 2010-05-21 18:31:26 -04:00
ubifs ubifs: replace inode uid,gid,mode initialization with helper function 2010-05-21 18:31:26 -04:00
udf udf: replace inode uid,gid,mode init with helper 2010-05-21 18:31:27 -04:00
ufs ufs: replace inode uid,gid,mode initialization with helper function 2010-05-21 18:31:27 -04:00
xfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2010-03-19 09:43:06 -07:00
Kconfig.binfmt
Makefile Take statfs variants to fs/statfs.c 2010-05-21 18:31:17 -04:00
aio.c aio: remove unused field 2009-12-16 07:20:13 -08:00
anon_inodes.c anon_inode: set S_IFREG on the anon_inode 2010-05-21 18:31:20 -04:00
attr.c fs: use rlimit helpers 2010-03-06 11:26:29 -08:00
bad_inode.c
binfmt_aout.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
binfmt_elf.c coredump: pass mm->flags as a coredump parameter for consistency 2010-03-06 11:26:46 -08:00
binfmt_elf_fdpic.c Remove redundant check for CONFIG_MMU 2010-04-27 09:01:26 -07:00
binfmt_em86.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
binfmt_flat.c uclinux: error message when FLAT reloc symbol is invalid, v2 2010-04-21 13:28:49 +10:00
binfmt_misc.c
binfmt_script.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
binfmt_som.c Split 'flush_old_exec' into two functions 2010-01-29 08:22:01 -08:00
bio-integrity.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
bio.c Merge branch 'master' into for-linus 2010-03-19 08:05:10 +01:00
block_dev.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
buffer.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
char_dev.c fs/char_dev.c: remove useless loop 2009-09-24 07:21:03 -07:00
compat.c revert "procfs: provide stack information for threads" and its fixup commits 2010-05-11 17:33:41 -07:00
compat_binfmt_elf.c elf coredump: replace ELF_CORE_EXTRA_* macros by functions 2010-03-06 11:26:45 -08:00
compat_ioctl.c pktcdvd: improve BKL and compat_ioctl.c usage 2010-04-29 08:44:37 -07:00
dcache.c fix prune_dcache()/umount() race 2010-05-21 18:31:16 -04:00
dcookies.c
direct-io.c dio: fix use-after-free 2009-12-17 04:52:13 -05:00
drop_caches.c new helper: iterate_supers() 2010-05-21 18:31:16 -04:00
eventfd.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
eventpoll.c sched, wait: Use wrapper functions 2010-05-11 17:43:58 +02:00
exec.c revert "procfs: provide stack information for threads" and its fixup commits 2010-05-11 17:33:41 -07:00
fcntl.c Merge branch 'master' into for-2.6.35 2010-05-21 21:27:26 +02:00
fifo.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
file.c fs: use rlimit helpers 2010-03-06 11:26:29 -08:00
file_table.c vfs: take f_lock on modifying f_mode after open time 2010-03-06 11:26:25 -08:00
filesystems.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fs-writeback.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
fs_struct.c
generic_acl.c fs: xattr_handler table should be const 2010-05-21 18:31:18 -04:00
inode.c vfs: Add inode uid,gid,mode init helper 2010-05-21 18:31:22 -04:00
internal.h Bury __put_super_and_need_restart() 2010-05-21 18:31:16 -04:00
ioctl.c Introduce freeze_super and thaw_super for the fsfreeze ioctl 2010-05-21 18:31:18 -04:00
ioprio.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
libfs.c FS / libfs: Implement simple_write_to_buffer 2010-05-10 23:08:17 +02:00
locks.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
mbcache.c
mpage.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
namei.c namei.c : update mnt when it needed 2010-05-21 18:31:22 -04:00
namespace.c Merge branch 'next' into for-linus 2010-05-18 08:57:00 +10:00
nfsctl.c Switch may_open() and break_lease() to passing O_... 2010-03-03 13:00:21 -05:00
no-block.c
open.c Take statfs variants to fs/statfs.c 2010-05-21 18:31:17 -04:00
pipe.c pipe: set lower and upper limit on max pages in the pipe page array 2010-05-21 21:12:52 +02:00
pnode.c Kill CL_PROPAGATION, sanitize fs/pnode.c:get_source() 2010-03-03 13:00:22 -05:00
pnode.h VFS: Clean up shared mount flag propagation 2010-03-03 14:07:55 -05:00
posix_acl.c
read_write.c do_sync_read/write() should set kiocb.ki_nbytes to be consistent 2010-03-24 16:43:29 -07:00
read_write.h
readdir.c
select.c Add generic sys_old_select() 2010-03-12 15:52:32 -08:00
seq_file.c seq_file: fix new kernel-doc warnings 2010-03-07 15:48:26 -08:00
signalfd.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
splice.c pipe: add support for shrinking and growing pipes 2010-05-21 21:12:40 +02:00
stack.c VFS/fsstack: handle 32-bit smp + preempt + large files in fsstack_copy_inode_size 2009-12-17 10:58:17 -05:00
stat.c Add unlocked version of inode_add_bytes() function 2009-12-23 13:33:54 +01:00
statfs.c Take statfs variants to fs/statfs.c 2010-05-21 18:31:17 -04:00
super.c vfs: add lockdep annotation to s_vfs_rename_key for ecryptfs 2010-05-21 18:31:22 -04:00
sync.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-05-21 19:37:45 -07:00
timerfd.c fs/timerfd.c: make use of wait_event_interruptible_locked_irq() 2010-05-20 13:21:42 -07:00
utimes.c
xattr.c fs: xattr_handler table should be const 2010-05-21 18:31:18 -04:00
xattr_acl.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00