linux-mainline/fs
Heinrich Schuchardt 820c12d5d6 fallocate: create FAN_MODIFY and IN_MODIFY events
The fanotify and the inotify API can be used to monitor changes of the
file system.  System call fallocate() modifies files.  Hence it should
trigger the corresponding fanotify (FAN_MODIFY) and inotify (IN_MODIFY)
events.  The most interesting case is FALLOC_FL_COLLAPSE_RANGE because
this value allows to create arbitrary file content from random data.

This patch adds the missing call to fsnotify_modify().

The FAN_MODIFY and IN_MODIFY event will be created when fallocate()
succeeds.  It will even be created if the file length remains unchanged,
e.g.  when calling fanotify with flag FALLOC_FL_KEEP_SIZE.

This logic was primarily chosen to keep the coding simple.

It resembles the logic of the write() system call.

When we call write() we always create a FAN_MODIFY event, even in the case
of overwriting with identical data.

Events FAN_MODIFY and IN_MODIFY do not provide any guarantee that data was
actually changed.

Furthermore even if if the filesize remains unchanged, fallocate() may
influence whether a subsequent write() will succeed and hence the
fallocate() call may be considered a modification.

The fallocate(2) man page teaches: After a successful call, subsequent
writes into the range specified by offset and len are guaranteed not to
fail because of lack of disk space.

So calling fallocate(fd, FALLOC_FL_KEEP_SIZE, offset, len) may result in
different outcomes of a subsequent write depending on the values of offset
and len.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@parisplace.org>
Cc: John McCutchan <john@johnmccutchan.com>
Cc: Robert Love <rlove@rlove.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
..
9p
adfs
affs fs/affs/file.c: remove obsolete pagesize check 2014-12-13 12:42:52 -08:00
afs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
autofs4
befs befs: remove dead code 2014-12-13 12:42:51 -08:00
bfs
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-12-12 11:15:23 -08:00
cachefiles
ceph Merge branch 'iov_iter' into for-next 2014-12-08 20:39:29 -05:00
cifs Merge branch 'akpm' (patchbomb from Andrew) 2014-12-10 18:34:42 -08:00
coda
configfs
cramfs
debugfs
devpts
dlm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-10 16:10:49 -08:00
ecryptfs
efivarfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-10 16:10:49 -08:00
efs
exofs
exportfs
ext2
ext3
ext4 Lots of bugs fixes, including Zheng and Jan's extent status shrinker 2014-12-12 09:28:03 -08:00
f2fs f2fs: avoid to ra unneeded blocks in recover flow 2014-12-08 14:19:09 -08:00
fat fat: fix data past EOF resulting from fsx testsuite 2014-12-13 12:42:51 -08:00
freevxfs
fscache
fuse
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-10 16:10:49 -08:00
hfs fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp 2014-12-10 17:41:16 -08:00
hfsplus
hostfs
hpfs
hppfs
hugetlbfs mm: convert i_mmap_mutex to rwsem 2014-12-13 12:42:45 -08:00
isofs
jbd
jbd2 Lots of bugs fixes, including Zheng and Jan's extent status shrinker 2014-12-12 09:28:03 -08:00
jffs2
jfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-10 16:10:49 -08:00
kernfs
lockd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-10 16:10:49 -08:00
logfs
minix
ncpfs Merge branch 'akpm' (patchbomb from Andrew) 2014-12-10 18:34:42 -08:00
nfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-10 16:10:49 -08:00
nfs_common
nfsd Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-12-11 14:27:06 -08:00
nilfs2 nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races 2014-12-10 17:41:16 -08:00
nls
notify Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-10 16:10:49 -08:00
ntfs
ocfs2 Merge branch 'akpm' (patchbomb from Andrew) 2014-12-10 18:34:42 -08:00
omfs
openpromfs
overlayfs Merge branch 'iov_iter' into for-next 2014-12-08 20:39:29 -05:00
proc Merge branch 'akpm' (patchbomb from Andrew) 2014-12-10 18:34:42 -08:00
pstore pstore-ram: Allow optional mapping with pgprot_noncached 2014-12-11 13:38:31 -08:00
qnx4
qnx6
quota
ramfs
reiserfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2014-12-12 10:08:06 -08:00
romfs
squashfs
sysfs
sysv
ubifs
udf
ufs
xfs xfs: update for 3.19-rc1 2014-12-12 09:48:17 -08:00
aio.c Merge git://git.kvack.org/~bcrl/aio-fixes 2014-11-25 18:55:44 -08:00
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2014-12-11 17:56:37 -08:00
binfmt_em86.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
binfmt_flat.c
binfmt_misc.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
binfmt_script.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
binfmt_som.c
block_dev.c
buffer.c
char_dev.c fs/char_dev.c: remove pointless assignment from __register_chrdev_region() 2014-12-10 17:41:04 -08:00
compat_binfmt_elf.c
compat_ioctl.c
compat.c
coredump.c
dcache.c Merge branch 'iov_iter' into for-next 2014-12-08 20:39:29 -05:00
dcookies.c
direct-io.c
drop_caches.c mm: vmscan: invoke slab shrinkers from shrink_zone() 2014-12-13 12:42:48 -08:00
eventfd.c
eventpoll.c
exec.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
fcntl.c
fhandle.c
file_table.c
file.c fs/file.c: replace get_unused_fd() with get_unused_fd_flags(0) 2014-12-10 17:41:10 -08:00
filesystems.c
fs_pin.c
fs_struct.c
fs-writeback.c
inode.c mm: convert i_mmap_mutex to rwsem 2014-12-13 12:42:45 -08:00
internal.h
ioctl.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mount.h
mpage.c
namei.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
namespace.c
no-block.c
open.c fallocate: create FAN_MODIFY and IN_MODIFY events 2014-12-13 12:42:53 -08:00
pipe.c
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c
readdir.c
select.c
seq_file.c fs, seq_file: fallback to vmalloc instead of oom kill processes 2014-12-13 12:42:49 -08:00
signalfd.c
splice.c
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
utimes.c
xattr.c