linux/fs
Chris Mason b1bf862e9d Btrfs: fix regressions in copy_from_user handling
Commit 914ee295af fixed deadlocks in
btrfs_file_write where we would catch page faults on pages we had
locked.

But, there were a few problems:

1) The x86-32 iov_iter_copy_from_user_atomic code always fails to copy
data when the amount to copy is more than 4K and the offset to start
copying from is not page aligned.  The result was btrfs_file_write
looping forever retrying the iov_iter_copy_from_user_atomic

We deal with this by changing btrfs_file_write to drop down to single
page copies when iov_iter_copy_from_user_atomic starts returning failure.

2) The btrfs_file_write code was leaking delalloc reservations when
iov_iter_copy_from_user_atomic returned zero.  The looping above would
result in the entire filesystem running out of delalloc reservations and
constantly trying to flush things to disk.

3) btrfs_file_write will lock down page cache pages, make sure
any writeback is finished, do the copy_from_user and then release them.
Before the loop runs we check the first and last pages in the write to
see if they are only being partially modified.  If the start or end of
the write isn't aligned, we make sure the corresponding pages are
up to date so that we don't introduce garbage into the file.

With the copy_from_user changes, we're allowing the VM to reclaim the
pages after a partial update from copy_from_user, but we're not
making sure the page cache page is up to date when we loop around to
resume the write.

We deal with this by pushing the up to date checks down into the page
prep code.  This fits better with how the rest of file_write works.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org>
cc: stable@kernel.org
2011-03-07 10:42:27 -05:00
..
9p fs/9p: Don't use dotl version of mknod for dotu inode operations 2010-09-13 08:13:03 -05:00
adfs check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
affs AFFS: wait for sb synchronization when needed 2010-08-09 16:48:51 -04:00
afs Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6 2010-08-13 10:37:30 -07:00
autofs autofs/autofs4: Move compat_ioctl handling into fs 2010-08-09 00:13:34 +02:00
autofs4 autofs4: remove unneeded null check in try_to_fill_dentry() 2010-08-11 08:59:06 -07:00
befs
bfs BFS: clean up the superblock usage 2010-08-09 16:48:53 -04:00
btrfs Btrfs: fix regressions in copy_from_user handling 2011-03-07 10:42:27 -05:00
cachefiles Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
ceph ceph: update issue_seq on cap grant 2010-10-07 08:01:50 -07:00
cifs cifs: prevent infinite recursion in cifs_reconnect_tcon 2010-10-01 17:50:08 +00:00
coda Coda: mount hangs because of missed REQ_WRITE rename 2010-09-19 11:03:09 -07:00
configfs
cramfs cramfs: only unlock new inodes 2010-08-18 01:01:33 -04:00
debugfs
devpts
dlm fs/dlm: Drop unnecessary null test 2010-08-05 14:23:45 -05:00
ecryptfs eCryptfs: Fix encrypted file name lookup regression 2010-08-27 10:50:53 -05:00
efs
exofs exofs: Fix double page_unlock BUG in write_begin/end 2010-10-08 11:26:54 -04:00
exportfs
ext2 mbcache: Remove unused features 2010-08-09 16:48:45 -04:00
ext3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
fat remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
freevxfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
fscache Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
fuse fuse: Initialize total_len in fuse_retrieve() 2010-10-04 10:45:32 +02:00
gfs2 GFS2: gfs2_logd should be using interruptible waits 2010-09-17 14:00:10 +01:00
hfs convert remaining ->clear_inode() to ->evict_inode() 2010-08-09 16:48:37 -04:00
hfsplus convert remaining ->clear_inode() to ->evict_inode() 2010-08-09 16:48:37 -04:00
hostfs hostfs ->follow_link() braino 2010-08-18 06:21:10 -04:00
hpfs switch hpfs to ->evict_inode() 2010-08-09 16:48:17 -04:00
hppfs switch hppfs to ->evict_inode() 2010-08-09 16:48:16 -04:00
hugetlbfs new helper: end_writeback() 2010-08-09 16:47:49 -04:00
isofs isofs: Fix lseek() to position beyond 4 GB 2010-08-11 00:29:47 -04:00
jbd remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
jbd2 remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2010-08-10 11:49:21 -07:00
jfs jfs: don't allow os2 xattr namespace overlap with others 2010-08-10 15:33:09 -07:00
lockd
logfs logfs: kill BKL 2010-08-14 00:24:24 +02:00
minix minix: fix regression in minix_mkdir() 2010-09-09 18:57:25 -07:00
ncpfs Merge branch 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing 2010-08-10 13:58:28 -07:00
nfs SUNRPC: Fix the NFSv4 and RPCSEC_GSS Kconfig dependencies 2010-09-12 19:57:50 -04:00
nfs_common
nfsd nfsd: fix BUG at fs/nfsd/nfsfh.h:199 on unlink 2010-10-13 15:48:55 -04:00
nilfs2 nilfs2: fix leak of shadow dat inode in error path of load_nilfs 2010-08-30 10:18:03 +09:00
nls
notify fanotify: disable fanotify syscalls 2010-10-11 18:15:28 -07:00
ntfs convert remaining ->clear_inode() to ->evict_inode() 2010-08-09 16:48:37 -04:00
ocfs2 ocfs2: Don't walk off the end of fast symlinks. 2010-09-29 17:33:05 -07:00
omfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bcopeland/omfs 2010-08-10 11:47:36 -07:00
openpromfs
partitions [S390] partitions: fix build error in ibm partition detection code 2010-08-13 10:06:55 +02:00
proc proc: make /proc/pid/limits world readable 2010-10-01 10:50:59 -07:00
qnx4 get rid of cont_write_begin_newtrunc 2010-08-09 16:47:31 -04:00
quota Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
ramfs check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
reiserfs reiserfs: fix unwanted reiserfs lock recursion 2010-10-01 10:50:59 -07:00
romfs
smbfs switch smbfs to evict_inode() 2010-08-09 16:48:00 -04:00
squashfs Squashfs: fix checkpatch.pl warnings 2010-08-08 22:29:33 +00:00
sysfs sysfs: checking for NULL instead of ERR_PTR 2010-09-03 17:26:28 -07:00
sysv fs/sysv/super.c: add support for non-PDP11 v7 filesystems 2010-08-11 08:59:23 -07:00
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
udf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
ufs remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
xfs xfs: properly account for reclaimed inodes 2010-10-06 22:35:48 -05:00
aio.c aio: do not return ERESTARTSYS as a result of AIO 2010-09-22 17:22:39 -07:00
anon_inodes.c
attr.c check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
bad_inode.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
binfmt_aout.c Don't dump task struct in a.out core-dumps 2010-10-14 10:57:40 -07:00
binfmt_elf_fdpic.c
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c flat: tweak default stack alignment 2010-06-29 15:29:31 -07:00
binfmt_misc.c binfmt_misc: fix binfmt_misc priority 2010-09-09 18:57:24 -07:00
binfmt_script.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
binfmt_som.c
bio-integrity.c fs/bio-integrity.c: return -ENOMEM on kmalloc failure 2010-08-23 13:36:59 +02:00
bio.c block: unify flags for struct bio and struct request 2010-08-07 18:20:39 +02:00
block_dev.c blkdev: cgroup whitelist permission fix 2010-08-11 08:59:18 -07:00
buffer.c remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
char_dev.c char: Mark /dev/zero and /dev/kmem as not capable of writeback 2010-09-22 09:48:47 +02:00
compat_binfmt_elf.c
compat_ioctl.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
compat.c Prevent freeing uninitialized pointer in compat_do_readv_writev 2010-09-22 17:22:38 -07:00
dcache.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
dcookies.c
direct-io.c O_DIRECT: fix the splitting up of contiguous I/O 2010-09-09 18:57:22 -07:00
drop_caches.c simplify checks for I_CLEAR/I_FREEING 2010-08-09 16:47:44 -04:00
eventfd.c
eventpoll.c
exec.c Export dump_{write,seek} to binary loader modules 2010-10-14 19:15:28 -07:00
fcntl.c vfs: take O_NONBLOCK out of the O_* uniqueness test 2010-09-09 18:57:25 -07:00
fifo.c
file_table.c fs: scale files_lock 2010-08-18 08:35:48 -04:00
file.c vfs: use kmalloc() to allocate fdmem if possible 2010-08-11 08:59:02 -07:00
filesystems.c
fs_struct.c fs: fs_struct rwlock to spinlock 2010-08-18 08:35:46 -04:00
fs-writeback.c Add new functions for triggering inode writeback 2010-10-29 11:25:29 -04:00
generic_acl.c vfs: update ctime when changing the file's permission by setfacl 2010-08-18 01:04:22 -04:00
inode.c Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify 2010-08-10 11:39:13 -07:00
internal.h fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
ioctl.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
ioprio.c
Kconfig fs/Kconfig: Fix typo Userpace -> Userspace 2010-07-20 17:30:22 +02:00
Kconfig.binfmt
libfs.c check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
locks.c
Makefile
mbcache.c mbcache: Limit the maximum number of cache entries 2010-08-18 06:24:41 -04:00
mpage.c
namei.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
namespace.c VFS: Sanity check mount flags passed to change_mnt_propagation() 2010-09-07 13:46:20 -07:00
nfsctl.c
no-block.c
open.c fs: cleanup files_lock locking 2010-08-18 08:35:47 -04:00
pipe.c
pnode.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
pnode.h
posix_acl.c
read_write.c fsnotify: pass a file instead of an inode to open, read, and write 2010-07-28 09:58:32 -04:00
read_write.h
readdir.c vfs: fix warning: 'dirent' is used uninitialized in this function 2010-08-09 20:45:05 -07:00
select.c
seq_file.c
signalfd.c signalfd: fill in ssi_int for posix timers and message queues 2010-08-11 08:59:20 -07:00
splice.c splice: fix misuse of SPLICE_F_NONBLOCK 2010-08-07 18:52:56 +02:00
stack.c
stat.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
statfs.c add f_flags to struct statfs(64) 2010-08-09 16:48:44 -04:00
super.c fs: scale files_lock 2010-08-18 08:35:48 -04:00
sync.c get rid of file_fsync() 2010-08-09 16:47:43 -04:00
timerfd.c
utimes.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
xattr_acl.c
xattr.c