linux/fs/ext2
Mikulas Patocka 1ef6ea0efe ext2: don't update mtime on COW faults
When running in a dax mode, if the user maps a page with MAP_PRIVATE and
PROT_WRITE, the ext2 filesystem would incorrectly update ctime and mtime
when the user hits a COW fault.

This breaks building of the Linux kernel.  How to reproduce:

 1. extract the Linux kernel tree on dax-mounted ext2 filesystem
 2. run make clean
 3. run make -j12
 4. run make -j12

at step 4, make would incorrectly rebuild the whole kernel (although it
was already built in step 3).

The reason for the breakage is that almost all object files depend on
objtool.  When we run objtool, it takes COW page fault on its .data
section, and these faults will incorrectly update the timestamp of the
objtool binary.  The updated timestamp causes make to rebuild the whole
tree.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-05 10:00:05 -07:00
..
acl.c ext2: cache NULL when both default_acl and acl are NULL 2018-09-03 11:05:03 +02:00
acl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
balloc.c ext2: fix improper function comment 2019-11-07 12:35:27 +01:00
dir.c ext2: ext2_find_entry() return -ENOENT if no entry found 2020-07-09 08:14:00 +02:00
ext2.h ext2: ext2.h: fix duplicated word + typos 2020-07-27 10:58:06 +02:00
file.c ext2: don't update mtime on COW faults 2020-09-05 10:00:05 -07:00
ialloc.c ext2: fix missing percpu_counter_inc 2020-07-09 08:14:01 +02:00
inode.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
ioctl.c ext2: return error when fail to allocating memory in ioctl 2019-10-24 09:24:40 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
namei.c ext2: ext2_find_entry() return -ENOENT if no entry found 2020-07-09 08:14:00 +02:00
super.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
symlink.c ext2: code cleanup by removing ifdef macro surrounding 2020-05-22 15:11:00 +02:00
xattr_security.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xattr_trusted.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xattr_user.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xattr.c ext2: initialize quota info in ext2_xattr_set() 2020-07-09 08:14:01 +02:00
xattr.h ext2: code cleanup by removing ifdef macro surrounding 2020-05-22 15:11:00 +02:00