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02d262dffc
linux/fs/ext4
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Dmitry Monakhov 02d262dffc ext4: punch_hole should wait for DIO writers 
punch_hole is the place where we have to wait for all existing writers
(writeback, aio, dio), but currently we simply flush pended end_io request
which is not sufficient. Other issue is that punch_hole performed w/o i_mutex
held which obviously result in dangerous data corruption due to
write-after-free.

This patch performs following changes:
- Guard punch_hole with i_mutex
- Recheck inode flags under i_mutex
- Block all new dio readers in order to prevent information leak caused by
  read-after-free pattern.
- punch_hole now wait for all writers in flight
  NOTE: XXX write-after-free race is still possible because new dirty pages
  may appear due to mmap(), and currently there is no easy way to stop
  writeback while punch_hole is in progress.

[ Fixed error return from ext4_ext_punch_hole() to make sure that we
  release i_mutex before returning EPERM or ETXTBUSY -- Ted ]

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-09-30 23:03:42 -04:00
..
acl.c switch posix_acl_equiv_mode() to umode_t * 2011-08-01 02:10:06 -04:00
acl.h fs: take the ACL checks to common code 2011-07-25 14:30:23 -04:00
balloc.c ext4: don't call ext4_error while block group is locked 2012-08-17 09:06:06 -04:00
bitmap.c ext4: don't call ext4_error while block group is locked 2012-08-17 09:06:06 -04:00
block_validity.c ext2/3/4: delete unneeded includes of module.h 2012-01-09 13:52:10 +01:00
dir.c ext4: use core vfs llseek code for dir seeks 2012-07-23 00:00:28 +04:00
ext4_extents.h ext4: verify and calculate checksums for extent tree blocks 2012-04-29 18:37:10 -04:00
ext4_jbd2.c ext4: remove unnecessary argument from __ext4_handle_dirty_metadata() 2012-07-22 20:37:31 -04:00
ext4_jbd2.h ext4: remove unnecessary argument from __ext4_handle_dirty_metadata() 2012-07-22 20:37:31 -04:00
ext4.h ext4: serialize dio nonlocked reads with defrag workers 2012-09-29 00:41:21 -04:00
extents.c ext4: punch_hole should wait for DIO writers 2012-09-30 23:03:42 -04:00
file.c ext4: give i_aiodio_unwritten a more appropriate name 2012-09-28 23:24:52 -04:00
fsync.c ext4: completed_io locking cleanup 2012-09-29 00:14:55 -04:00
hash.c ext4: return 32/64-bit dir name hash according to usage type 2012-03-18 22:44:40 -04:00
ialloc.c ext4: check free inode count before allocating an inode 2012-09-23 23:16:03 -04:00
indirect.c ext4: serialize dio nonlocked reads with defrag workers 2012-09-29 00:41:21 -04:00
inode.c ext4: serialize truncate with owerwrite DIO workers 2012-09-29 00:58:26 -04:00
ioctl.c ext4: release donor reference when EXT4_IOC_MOVE_EXT ioctl fails 2012-09-26 22:58:50 -04:00
Kconfig ext4: load the crc32c driver if necessary 2012-04-29 18:27:10 -04:00
Makefile ext4: move ext4_ind_* functions from inode.c to indirect.c 2011-06-27 19:40:50 -04:00
mballoc.c ext4: enable FITRIM ioctl on bigalloc file system 2012-09-26 22:21:21 -04:00
mballoc.h ext4: remove unused macro MB_DEFAULT_MAX_GROUPS_TO_SCAN 2012-08-17 10:00:17 -04:00
migrate.c userns: Convert ext4 to user kuid/kgid where appropriate 2012-05-15 14:59:27 -07:00
mmp.c ext4: Convert to new freezing mechanism 2012-07-31 09:45:48 +04:00
move_extent.c ext4: serialize dio nonlocked reads with defrag workers 2012-09-29 00:41:21 -04:00
namei.c ext4: ext4_bread usage audit 2012-09-27 09:31:33 -04:00
page-io.c ext4: completed_io locking cleanup 2012-09-29 00:14:55 -04:00
resize.c ext4: don't call update_backups() multiple times for the same bg 2012-09-26 00:08:57 -04:00
super.c ext4: give i_aiodio_unwritten a more appropriate name 2012-09-28 23:24:52 -04:00
symlink.c
truncate.h ext4: move common truncate functions to header file 2011-06-27 19:16:04 -04:00
xattr_security.c Merge branch 'for_linus' into for_linus_merged 2012-01-10 11:54:07 -05:00
xattr_trusted.c ext2/3/4: delete unneeded includes of module.h 2012-01-09 13:52:10 +01:00
xattr_user.c ext2/3/4: delete unneeded includes of module.h 2012-01-09 13:52:10 +01:00
xattr.c ext4: use s_csum_seed instead of i_csum_seed for xattr block 2012-07-09 16:29:27 -04:00
xattr.h ext4: change on-disk layout to support extended metadata checksumming 2012-04-29 18:23:10 -04:00