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  1. 08 8月, 2020 3 次提交
  3. 06 8月, 2020 14 次提交
  5. 30 7月, 2020 1 次提交
  7. 13 6月, 2020 2 次提交
  9. 11 6月, 2020 5 次提交
    • R
      ext4: mballoc: Use this_cpu_read instead of this_cpu_ptr · 81198536
      由 Ritesh Harjani 提交于 
      Simplify reading a seq variable by directly using this_cpu_read API
instead of doing this_cpu_ptr and then dereferencing it.

This also avoid the below kernel BUG: which happens when
CONFIG_DEBUG_PREEMPT is enabled

BUG: using smp_processor_id() in preemptible [00000000] code: syz-fuzzer/6927
caller is ext4_mb_new_blocks+0xa4d/0x3b70 fs/ext4/mballoc.c:4711
CPU: 1 PID: 6927 Comm: syz-fuzzer Not tainted 5.7.0-next-20200602-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 check_preemption_disabled+0x20d/0x220 lib/smp_processor_id.c:48
 ext4_mb_new_blocks+0xa4d/0x3b70 fs/ext4/mballoc.c:4711
 ext4_ext_map_blocks+0x201b/0x33e0 fs/ext4/extents.c:4244
 ext4_map_blocks+0x4cb/0x1640 fs/ext4/inode.c:626
 ext4_getblk+0xad/0x520 fs/ext4/inode.c:833
 ext4_bread+0x7c/0x380 fs/ext4/inode.c:883
 ext4_append+0x153/0x360 fs/ext4/namei.c:67
 ext4_init_new_dir fs/ext4/namei.c:2757 [inline]
 ext4_mkdir+0x5e0/0xdf0 fs/ext4/namei.c:2802
 vfs_mkdir+0x419/0x690 fs/namei.c:3632
 do_mkdirat+0x21e/0x280 fs/namei.c:3655
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 42f56b7a4a7d ("ext4: mballoc: introduce pcpu seqcnt for freeing PA
to improve ENOSPC handling")
Suggested-by: NBorislav Petkov <bp@alien8.de>
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NRitesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reported-by: syzbot+82f324bb69744c5f6969@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/534f275016296996f54ecf65168bb3392b6f653d.1591699601.git.riteshh@linux.ibm.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
      81198536
    • E
      ext4: avoid utf8_strncasecmp() with unstable name · 2ce3ee93
      由 Eric Biggers 提交于 
      If the dentry name passed to ->d_compare() fits in dentry::d_iname, then
it may be concurrently modified by a rename.  This can cause undefined
behavior (possibly out-of-bounds memory accesses or crashes) in
utf8_strncasecmp(), since fs/unicode/ isn't written to handle strings
that may be concurrently modified.

Fix this by first copying the filename to a stack buffer if needed.
This way we get a stable snapshot of the filename.

Fixes: b886ee3e ("ext4: Support case-insensitive file name lookups")
Cc: <stable@vger.kernel.org> # v5.2+
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Daniel Rosenberg <drosen@google.com>
Cc: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NAndreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20200601200543.59417-1-ebiggers@kernel.orgSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
      2ce3ee93
    • Y
      ext4: stop overwrite the errcode in ext4_setup_super · 5adaccac
      由 yangerkun 提交于 
      Now the errcode from ext4_commit_super will overwrite EROFS exists in
ext4_setup_super. Actually, no need to call ext4_commit_super since we
will return EROFS. Fix it by goto done directly.

Fixes: c89128a0 ("ext4: handle errors on ext4_commit_super")
Signed-off-by: Nyangerkun <yangerkun@huawei.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200601073404.3712492-1-yangerkun@huawei.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
      5adaccac
    • J
      ext4: fix partial cluster initialization when splitting extent · cfb3c85a
      由 Jeffle Xu 提交于 
      Fix the bug when calculating the physical block number of the first
block in the split extent.

This bug will cause xfstests shared/298 failure on ext4 with bigalloc
enabled occasionally. Ext4 error messages indicate that previously freed
blocks are being freed again, and the following fsck will fail due to
the inconsistency of block bitmap and bg descriptor.

The following is an example case:

1. First, Initialize a ext4 filesystem with cluster size '16K', block size
'4K', in which case, one cluster contains four blocks.

2. Create one file (e.g., xxx.img) on this ext4 filesystem. Now the extent
tree of this file is like:

...
36864:[0]4:220160
36868:[0]14332:145408
51200:[0]2:231424
...

3. Then execute PUNCH_HOLE fallocate on this file. The hole range is
like:

..
ext4_ext_remove_space: dev 254,16 ino 12 since 49506 end 49506 depth 1
ext4_ext_remove_space: dev 254,16 ino 12 since 49544 end 49546 depth 1
ext4_ext_remove_space: dev 254,16 ino 12 since 49605 end 49607 depth 1
...

4. Then the extent tree of this file after punching is like

...
49507:[0]37:158047
49547:[0]58:158087
...

5. Detailed procedure of punching hole [49544, 49546]

5.1. The block address space:
```
lblk        ~49505  49506   49507~49543     49544~49546    49547~
	  ---------+------+-------------+----------------+--------
	    extent | hole |   extent	|	hole	 | extent
	  ---------+------+-------------+----------------+--------
pblk       ~158045  158046  158047~158083  158084~158086   158087~
```

5.2. The detailed layout of cluster 39521:
```
		cluster 39521
	<------------------------------->

		hole		  extent
	<----------------------><--------

lblk      49544   49545   49546   49547
	+-------+-------+-------+-------+
	|	|	|	|	|
	+-------+-------+-------+-------+
pblk     158084  1580845  158086  158087
```

5.3. The ftrace output when punching hole [49544, 49546]:
- ext4_ext_remove_space (start 49544, end 49546)
  - ext4_ext_rm_leaf (start 49544, end 49546, last_extent [49507(158047), 40], partial [pclu 39522 lblk 0 state 2])
    - ext4_remove_blocks (extent [49507(158047), 40], from 49544 to 49546, partial [pclu 39522 lblk 0 state 2]
      - ext4_free_blocks: (block 158084 count 4)
        - ext4_mballoc_free (extent 1/6753/1)

5.4. Ext4 error message in dmesg:
EXT4-fs error (device vdb): mb_free_blocks:1457: group 1, block 158084:freeing already freed block (bit 6753); block bitmap corrupt.
EXT4-fs error (device vdb): ext4_mb_generate_buddy:747: group 1, block bitmap and bg descriptor inconsistent: 19550 vs 19551 free clusters

In this case, the whole cluster 39521 is freed mistakenly when freeing
pblock 158084~158086 (i.e., the first three blocks of this cluster),
although pblock 158087 (the last remaining block of this cluster) has
not been freed yet.

The root cause of this isuue is that, the pclu of the partial cluster is
calculated mistakenly in ext4_ext_remove_space(). The correct
partial_cluster.pclu (i.e., the cluster number of the first block in the
next extent, that is, lblock 49597 (pblock 158086)) should be 39521 rather
than 39522.

Fixes: f4226d9e ("ext4: fix partial cluster initialization")
Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: NEric Whitney <enwlinux@gmail.com>
Cc: stable@kernel.org # v3.19+
Link: https://lore.kernel.org/r/1590121124-37096-1-git-send-email-jefflexu@linux.alibaba.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>
      cfb3c85a
    • T
      ext4: avoid race conditions when remounting with options that change dax · 829b37b8
      由 Theodore Ts'o 提交于 
      Trying to change dax mount options when remounting could allow mount
options to be enabled for a small amount of time, and then the mount
option change would be reverted.

In the case of "mount -o remount,dax", this can cause a race where
files would temporarily treated as DAX --- and then not.

Cc: stable@kernel.org
Reported-by: syzbot+bca9799bf129256190da@syzkaller.appspotmail.com
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
      829b37b8
  11. 10 6月, 2020 1 次提交
  13. 04 6月, 2020 14 次提交