If sbi->s_flex_groups_allocated is zero and the first allocation fails
then this code will crash. The problem is that "i--" will set "i" to
-1 but when we compare "i >= sbi->s_flex_groups_allocated" then the -1
is type promoted to unsigned and becomes UINT_MAX. Since UINT_MAX
is more than zero, the condition is true so we call kvfree(new_groups[-1]).
The loop will carry on freeing invalid memory until it crashes.
Fixes: 7c990728b9 ("ext4: fix potential race between s_flex_groups online resizing and access")
Reviewed-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20200228092142.7irbc44yaz3by7nb@kili.mountain
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When CONFIG_QFMT_V2 is configured as a module, the test in
ext4_feature_set_ok() fails and so mount of filesystems with quota or
project features fails. Fix the test to use IS_ENABLED macro which
works properly even for modules.
Link: https://lore.kernel.org/r/20200221100835.9332-1-jack@suse.cz
Fixes: d65d87a074 ("ext4: improve explanation of a mount failure caused by a misconfigured kernel")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
If EXT4_EXTENTS_FL is set on an inode while ext4_writepages() is running
on it, the following warning in ext4_add_complete_io() can be hit:
WARNING: CPU: 1 PID: 0 at fs/ext4/page-io.c:234 ext4_put_io_end_defer+0xf0/0x120
Here's a minimal reproducer (not 100% reliable) (root isn't required):
while true; do
sync
done &
while true; do
rm -f file
touch file
chattr -e file
echo X >> file
chattr +e file
done
The problem is that in ext4_writepages(), ext4_should_dioread_nolock()
(which only returns true on extent-based files) is checked once to set
the number of reserved journal credits, and also again later to select
the flags for ext4_map_blocks() and copy the reserved journal handle to
ext4_io_end::handle. But if EXT4_EXTENTS_FL is being concurrently set,
the first check can see dioread_nolock disabled while the later one can
see it enabled, causing the reserved handle to unexpectedly be NULL.
Since changing EXT4_EXTENTS_FL is uncommon, and there may be other races
related to doing so as well, fix this by synchronizing changing
EXT4_EXTENTS_FL with ext4_writepages() via the existing
s_writepages_rwsem (previously called s_journal_flag_rwsem).
This was originally reported by syzbot without a reproducer at
https://syzkaller.appspot.com/bug?extid=2202a584a00fffd19fbf,
but now that dioread_nolock is the default I also started seeing this
when running syzkaller locally.
Link: https://lore.kernel.org/r/20200219183047.47417-3-ebiggers@kernel.org
Reported-by: syzbot+2202a584a00fffd19fbf@syzkaller.appspotmail.com
Fixes: 6b523df4fb ("ext4: use transaction reservation for extent conversion in ext4_end_io")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
In preparation for making s_journal_flag_rwsem synchronize
ext4_writepages() with changes to both the EXTENTS and JOURNAL_DATA
flags (rather than just JOURNAL_DATA as it does currently), rename it to
s_writepages_rwsem.
Link: https://lore.kernel.org/r/20200219183047.47417-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
During an online resize an array of s_flex_groups structures gets replaced
so it can get enlarged. If there is a concurrent access to the array and
this memory has been reused then this can lead to an invalid memory access.
The s_flex_group array has been converted into an array of pointers rather
than an array of structures. This is to ensure that the information
contained in the structures cannot get out of sync during a resize due to
an accessor updating the value in the old structure after it has been
copied but before the array pointer is updated. Since the structures them-
selves are no longer copied but only the pointers to them this case is
mitigated.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206443
Link: https://lore.kernel.org/r/20200221053458.730016-4-tytso@mit.edu
Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
During an online resize an array of pointers to s_group_info gets replaced
so it can get enlarged. If there is a concurrent access to the array in
ext4_get_group_info() and this memory has been reused then this can lead to
an invalid memory access.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206443
Link: https://lore.kernel.org/r/20200221053458.730016-3-tytso@mit.edu
Signed-off-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Balbir Singh <sblbir@amazon.com>
Cc: stable@kernel.org
During an online resize an array of pointers to buffer heads gets
replaced so it can get enlarged. If there is a racing block
allocation or deallocation which uses the old array, and the old array
has gotten reused this can lead to a GPF or some other random kernel
memory getting modified.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206443
Link: https://lore.kernel.org/r/20200221053458.730016-2-tytso@mit.edu
Reported-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
We tested a soft lockup problem in linux 4.19 which could also
be found in linux 5.x.
When dir inode takes up a large number of blocks, and if the
directory is growing when we are searching, it's possible the
restart branch could be called many times, and the do while loop
could hold cpu a long time.
Here is the call trace in linux 4.19.
[ 473.756186] Call trace:
[ 473.756196] dump_backtrace+0x0/0x198
[ 473.756199] show_stack+0x24/0x30
[ 473.756205] dump_stack+0xa4/0xcc
[ 473.756210] watchdog_timer_fn+0x300/0x3e8
[ 473.756215] __hrtimer_run_queues+0x114/0x358
[ 473.756217] hrtimer_interrupt+0x104/0x2d8
[ 473.756222] arch_timer_handler_virt+0x38/0x58
[ 473.756226] handle_percpu_devid_irq+0x90/0x248
[ 473.756231] generic_handle_irq+0x34/0x50
[ 473.756234] __handle_domain_irq+0x68/0xc0
[ 473.756236] gic_handle_irq+0x6c/0x150
[ 473.756238] el1_irq+0xb8/0x140
[ 473.756286] ext4_es_lookup_extent+0xdc/0x258 [ext4]
[ 473.756310] ext4_map_blocks+0x64/0x5c0 [ext4]
[ 473.756333] ext4_getblk+0x6c/0x1d0 [ext4]
[ 473.756356] ext4_bread_batch+0x7c/0x1f8 [ext4]
[ 473.756379] ext4_find_entry+0x124/0x3f8 [ext4]
[ 473.756402] ext4_lookup+0x8c/0x258 [ext4]
[ 473.756407] __lookup_hash+0x8c/0xe8
[ 473.756411] filename_create+0xa0/0x170
[ 473.756413] do_mkdirat+0x6c/0x140
[ 473.756415] __arm64_sys_mkdirat+0x28/0x38
[ 473.756419] el0_svc_common+0x78/0x130
[ 473.756421] el0_svc_handler+0x38/0x78
[ 473.756423] el0_svc+0x8/0xc
[ 485.755156] watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [tmp:5149]
Add cond_resched() to avoid soft lockup and to provide a better
system responding.
Link: https://lore.kernel.org/r/20200215080206.13293-1-luoshijie1@huawei.com
Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
EXT4_I(inode)->i_disksize could be accessed concurrently as noticed by
KCSAN,
BUG: KCSAN: data-race in ext4_write_end [ext4] / ext4_writepages [ext4]
write to 0xffff91c6713b00f8 of 8 bytes by task 49268 on cpu 127:
ext4_write_end+0x4e3/0x750 [ext4]
ext4_update_i_disksize at fs/ext4/ext4.h:3032
(inlined by) ext4_update_inode_size at fs/ext4/ext4.h:3046
(inlined by) ext4_write_end at fs/ext4/inode.c:1287
generic_perform_write+0x208/0x2a0
ext4_buffered_write_iter+0x11f/0x210 [ext4]
ext4_file_write_iter+0xce/0x9e0 [ext4]
new_sync_write+0x29c/0x3b0
__vfs_write+0x92/0xa0
vfs_write+0x103/0x260
ksys_write+0x9d/0x130
__x64_sys_write+0x4c/0x60
do_syscall_64+0x91/0xb47
entry_SYSCALL_64_after_hwframe+0x49/0xbe
read to 0xffff91c6713b00f8 of 8 bytes by task 24872 on cpu 37:
ext4_writepages+0x10ac/0x1d00 [ext4]
mpage_map_and_submit_extent at fs/ext4/inode.c:2468
(inlined by) ext4_writepages at fs/ext4/inode.c:2772
do_writepages+0x5e/0x130
__writeback_single_inode+0xeb/0xb20
writeback_sb_inodes+0x429/0x900
__writeback_inodes_wb+0xc4/0x150
wb_writeback+0x4bd/0x870
wb_workfn+0x6b4/0x960
process_one_work+0x54c/0xbe0
worker_thread+0x80/0x650
kthread+0x1e0/0x200
ret_from_fork+0x27/0x50
Reported by Kernel Concurrency Sanitizer on:
CPU: 37 PID: 24872 Comm: kworker/u261:2 Tainted: G W O L 5.5.0-next-20200204+ #5
Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019
Workqueue: writeback wb_workfn (flush-7:0)
Since only the read is operating as lockless (outside of the
"i_data_sem"), load tearing could introduce a logic bug. Fix it by
adding READ_ONCE() for the read and WRITE_ONCE() for the write.
Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/1581085751-31793-1-git-send-email-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Miscellaneous ext4 bug fixes (all stable fodder)"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: improve explanation of a mount failure caused by a misconfigured kernel
jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer
jbd2: move the clearing of b_modified flag to the journal_unmap_buffer()
ext4: add cond_resched() to ext4_protect_reserved_inode
ext4: fix checksum errors with indexed dirs
ext4: fix support for inode sizes > 1024 bytes
ext4: simplify checking quota limits in ext4_statfs()
ext4: don't assume that mmp_nodename/bdevname have NUL
If CONFIG_QFMT_V2 is not enabled, but CONFIG_QUOTA is enabled, when a
user tries to mount a file system with the quota or project quota
enabled, the kernel will emit a very confusing messsage:
EXT4-fs warning (device vdc): ext4_enable_quotas:5914: Failed to enable quota tracking (type=0, err=-3). Please run e2fsck to fix.
EXT4-fs (vdc): mount failed
We will now report an explanatory message indicating which kernel
configuration options have to be enabled, to avoid customer/sysadmin
confusion.
Link: https://lore.kernel.org/r/20200215012738.565735-1-tytso@mit.edu
Google-Bug-Id: 149093531
Fixes: 7c319d3285 ("ext4: make quota as first class supported feature")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
DIR_INDEX has been introduced as a compat ext4 feature. That means that
even kernels / tools that don't understand the feature may modify the
filesystem. This works because for kernels not understanding indexed dir
format, internal htree nodes appear just as empty directory entries.
Index dir aware kernels then check the htree structure is still
consistent before using the data. This all worked reasonably well until
metadata checksums were introduced. The problem is that these
effectively made DIR_INDEX only ro-compatible because internal htree
nodes store checksums in a different place than normal directory blocks.
Thus any modification ignorant to DIR_INDEX (or just clearing
EXT4_INDEX_FL from the inode) will effectively cause checksum mismatch
and trigger kernel errors. So we have to be more careful when dealing
with indexed directories on filesystems with checksumming enabled.
1) We just disallow loading any directory inodes with EXT4_INDEX_FL when
DIR_INDEX is not enabled. This is harsh but it should be very rare (it
means someone disabled DIR_INDEX on existing filesystem and didn't run
e2fsck), e2fsck can fix the problem, and we don't want to answer the
difficult question: "Should we rather corrupt the directory more or
should we ignore that DIR_INDEX feature is not set?"
2) When we find out htree structure is corrupted (but the filesystem and
the directory should in support htrees), we continue just ignoring htree
information for reading but we refuse to add new entries to the
directory to avoid corrupting it more.
Link: https://lore.kernel.org/r/20200210144316.22081-1-jack@suse.cz
Fixes: dbe8944404 ("ext4: Calculate and verify checksums for htree nodes")
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
A recent commit, 9803387c55 ("ext4: validate the
debug_want_extra_isize mount option at parse time"), moved mount-time
checks around. One of those changes moved the inode size check before
the blocksize variable was set to the blocksize of the file system.
After 9803387c55 was set to the minimum allowable blocksize, which
in practice on most systems would be 1024 bytes. This cuased file
systems with inode sizes larger than 1024 bytes to be rejected with a
message:
EXT4-fs (sdXX): unsupported inode size: 4096
Fixes: 9803387c55 ("ext4: validate the debug_want_extra_isize mount option at parse time")
Link: https://lore.kernel.org/r/20200206225252.GA3673@mit.edu
Reported-by: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Coverity reports that conditions checking quota limits in ext4_statfs()
contain dead code. Indeed it is right and current conditions can be
simplified.
Link: https://lore.kernel.org/r/20200130111148.10766-1-jack@suse.cz
Reported-by: Coverity <scan-admin@coverity.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
- Fix RWF_NOWAIT writes to properly return -EAGAIN
- Clean up an unused helper
- Update dax_writeback_mapping_range to not need a block_device argument
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Merge tag 'dax-fixes-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull dax fixes from Dan Williams:
"A fix for an xfstest failure and some and an update that removes an
fsdax dependency on block devices.
Summary:
- Fix RWF_NOWAIT writes to properly return -EAGAIN
- Clean up an unused helper
- Update dax_writeback_mapping_range to not need a block_device
argument"
* tag 'dax-fixes-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
dax: pass NOWAIT flag to iomap_apply
dax: Get rid of fs_dax_get_by_host() helper
dax: Pass dax_dev instead of bdev to dax_writeback_mapping_range()
handle inode locking in the read/write paths, and improving the
performance of Direct I/O overwrites. We also now record the error
code which caused the first and most recent ext4_error() report in the
superblock, to make it easier to root cause problems in production
systems. There are also many of the usual cleanups and miscellaneous
bug fixes.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"This merge window, we've added some performance improvements in how we
handle inode locking in the read/write paths, and improving the
performance of Direct I/O overwrites.
We also now record the error code which caused the first and most
recent ext4_error() report in the superblock, to make it easier to
root cause problems in production systems.
There are also many of the usual cleanups and miscellaneous bug fixes"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (49 commits)
jbd2: clean __jbd2_journal_abort_hard() and __journal_abort_soft()
jbd2: make sure ESHUTDOWN to be recorded in the journal superblock
ext4, jbd2: ensure panic when aborting with zero errno
jbd2: switch to use jbd2_journal_abort() when failed to submit the commit record
jbd2_seq_info_next should increase position index
jbd2: remove pointless assertion in __journal_remove_journal_head
ext4,jbd2: fix comment and code style
jbd2: delete the duplicated words in the comments
ext4: fix extent_status trace points
ext4: fix symbolic enum printing in trace output
ext4: choose hardlimit when softlimit is larger than hardlimit in ext4_statfs_project()
ext4: fix race conditions in ->d_compare() and ->d_hash()
ext4: make dioread_nolock the default
ext4: fix extent_status fragmentation for plain files
jbd2: clear JBD2_ABORT flag before journal_reset to update log tail info when load journal
ext4: drop ext4_kvmalloc()
ext4: Add EXT4_IOC_FSGETXATTR/EXT4_IOC_FSSETXATTR to compat_ioctl
ext4: remove unused macro MPAGE_DA_EXTENT_TAIL
ext4: add missing braces in ext4_ext_drop_refs()
ext4: fix some nonstandard indentation in extents.c
...
This kunit update for Linux 5.6-rc1 consists of:
-- Support for building kunit as a module from Alan Maguire
-- AppArmor KUnit tests for policy unpack from Mike Salvatore
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Merge tag 'linux-kselftest-5.6-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull Kselftest kunit updates from Shuah Khan:
"This kunit update consists of:
- Support for building kunit as a module from Alan Maguire
- AppArmor KUnit tests for policy unpack from Mike Salvatore"
* tag 'linux-kselftest-5.6-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
kunit: building kunit as a module breaks allmodconfig
kunit: update documentation to describe module-based build
kunit: allow kunit to be loaded as a module
kunit: remove timeout dependence on sysctl_hung_task_timeout_seconds
kunit: allow kunit tests to be loaded as a module
kunit: hide unexported try-catch interface in try-catch-impl.h
kunit: move string-stream.h to lib/kunit
apparmor: add AppArmor KUnit tests for policy unpack
- Optimize fs-verity sequential read performance by implementing
readahead of Merkle tree pages. This allows the Merkle tree to be
read in larger chunks.
- Optimize FS_IOC_ENABLE_VERITY performance in the uncached case by
implementing readahead of data pages.
- Allocate the hash requests from a mempool in order to eliminate the
possibility of allocation failures during I/O.
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Merge tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt
Pull fsverity updates from Eric Biggers:
- Optimize fs-verity sequential read performance by implementing
readahead of Merkle tree pages. This allows the Merkle tree to be
read in larger chunks.
- Optimize FS_IOC_ENABLE_VERITY performance in the uncached case by
implementing readahead of data pages.
- Allocate the hash requests from a mempool in order to eliminate the
possibility of allocation failures during I/O.
* tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
fs-verity: use u64_to_user_ptr()
fs-verity: use mempool for hash requests
fs-verity: implement readahead of Merkle tree pages
fs-verity: implement readahead for FS_IOC_ENABLE_VERITY
Show pblock only if it has meaningful value.
# before
ext4:ext4_es_lookup_extent_exit: dev 253,0 ino 12 found 1 [1/4294967294) 576460752303423487 H
ext4:ext4_es_lookup_extent_exit: dev 253,0 ino 12 found 1 [2/4294967293) 576460752303423487 HR
# after
ext4:ext4_es_lookup_extent_exit: dev 253,0 ino 12 found 1 [1/4294967294) 0 H
ext4:ext4_es_lookup_extent_exit: dev 253,0 ino 12 found 1 [2/4294967293) 0 HR
Signed-off-by: Dmitry Monakhov <dmonakhov@gmail.com>
Link: https://lore.kernel.org/r/20191114200147.1073-2-dmonakhov@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Setting softlimit larger than hardlimit seems meaningless
for disk quota but currently it is allowed. In this case,
there may be a bit of comfusion for users when they run
df comamnd to directory which has project quota.
For example, we set 20M softlimit and 10M hardlimit of
block usage limit for project quota of test_dir(project id 123).
[root@hades mnt_ext4]# repquota -P -a
*** Report for project quotas on device /dev/loop0
Block grace time: 7days; Inode grace time: 7days
Block limits File limits
Project used soft hard grace used soft hard grace
----------------------------------------------------------------------
0 -- 13 0 0 2 0 0
123 -- 10237 20480 10240 5 200 100
The result of df command as below:
[root@hades mnt_ext4]# df -h test_dir
Filesystem Size Used Avail Use% Mounted on
/dev/loop0 20M 10M 10M 50% /home/cgxu/test/mnt_ext4
Even though it looks like there is another 10M free space to use,
if we write new data to diretory test_dir(inherit project id),
the write will fail with errno(-EDQUOT).
After this patch, the df result looks like below.
[root@hades mnt_ext4]# df -h test_dir
Filesystem Size Used Avail Use% Mounted on
/dev/loop0 10M 10M 3.0K 100% /home/cgxu/test/mnt_ext4
Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20191016022501.760-1-cgxu519@mykernel.net
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since ->d_compare() and ->d_hash() can be called in RCU-walk mode,
->d_parent and ->d_inode can be concurrently modified, and in
particular, ->d_inode may be changed to NULL. For ext4_d_hash() this
resulted in a reproducible NULL dereference if a lookup is done in a
directory being deleted, e.g. with:
int main()
{
if (fork()) {
for (;;) {
mkdir("subdir", 0700);
rmdir("subdir");
}
} else {
for (;;)
access("subdir/file", 0);
}
}
... or by running the 't_encrypted_d_revalidate' program from xfstests.
Both repros work in any directory on a filesystem with the encoding
feature, even if the directory doesn't actually have the casefold flag.
I couldn't reproduce a crash in ext4_d_compare(), but it appears that a
similar crash is possible there.
Fix these bugs by reading ->d_parent and ->d_inode using READ_ONCE() and
falling back to the case sensitive behavior if the inode is NULL.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: b886ee3e77 ("ext4: Support case-insensitive file name lookups")
Cc: <stable@vger.kernel.org> # v5.2+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200124041234.159740-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Extents are cached in read_extent_tree_block(); as a result, extents
are not cached for inodes with depth == 0 when we try to find the
extent using ext4_find_extent(). The result of the lookup is cached
in ext4_map_blocks() but is only a subset of the extent on disk. As a
result, the contents of extents status cache can get very badly
fragmented for certain workloads, such as a random 4k read workload.
File size of /mnt/test is 33554432 (8192 blocks of 4096 bytes)
ext: logical_offset: physical_offset: length: expected: flags:
0: 0.. 8191: 40960.. 49151: 8192: last,eof
$ perf record -e 'ext4:ext4_es_*' /root/bin/fio --name=t --direct=0 --rw=randread --bs=4k --filesize=32M --size=32M --filename=/mnt/test
$ perf script | grep ext4_es_insert_extent | head -n 10
fio 131 [000] 13.975421: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [494/1) mapped 41454 status W
fio 131 [000] 13.975939: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [6064/1) mapped 47024 status W
fio 131 [000] 13.976467: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [6907/1) mapped 47867 status W
fio 131 [000] 13.976937: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [3850/1) mapped 44810 status W
fio 131 [000] 13.977440: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [3292/1) mapped 44252 status W
fio 131 [000] 13.977931: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [6882/1) mapped 47842 status W
fio 131 [000] 13.978376: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [3117/1) mapped 44077 status W
fio 131 [000] 13.978957: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [2896/1) mapped 43856 status W
fio 131 [000] 13.979474: ext4:ext4_es_insert_extent: dev 253,0 ino 12 es [7479/1) mapped 48439 status W
Fix this by caching the extents for inodes with depth == 0 in
ext4_find_extent().
[ Renamed ext4_es_cache_extents() to ext4_cache_extents() since this
newly added function is not in extents_cache.c, and to avoid
potential visual confusion with ext4_es_cache_extent(). -TYT ]
Signed-off-by: Dmitry Monakhov <dmonakhov@gmail.com>
Link: https://lore.kernel.org/r/20191106122502.19986-1-dmonakhov@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Remove unused macro MPAGE_DA_EXTENT_TAIL which
is no more used after below commit
4e7ea81d ("ext4: restructure writeback path")
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200101095137.25656-1-riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
For clarity, add braces to the loop in ext4_ext_drop_refs().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231180444.46586-9-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Clean up some code that was using 2-character indents.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231180444.46586-8-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Support for unwritten extents was added to ext4 a long time ago, so
remove a misleading comment that says they're a future feature.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231180444.46586-7-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Don't mention the nonexistent return value, and mention both types of
merges that are attempted.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231180444.46586-6-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Make the following functions static since they're only used in
extents.c:
__ext4_ext_dirty()
ext4_can_extents_be_merged()
ext4_collapse_range()
ext4_insert_range()
Also remove the prototype for ext4_ext_writepage_trans_blocks(), as this
function is not defined anywhere.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231180444.46586-5-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
ext4_fallocate() is only used in the file_operations for regular files.
Also, the VFS only allows fallocate() on regular files and block
devices, but block devices always use blkdev_fallocate(). For both of
these reasons, S_ISREG() is always true in ext4_fallocate().
Therefore the S_ISREG() checks in ext4_zero_range(),
ext4_collapse_range(), ext4_insert_range(), and ext4_punch_hole() are
redundant. Remove them.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231180444.46586-4-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
- Fix some comments.
- Consistently access i_size directly rather than using i_size_read(),
since in all relevant cases we're under inode_lock().
- Simplify the alignment checks by using the IS_ALIGNED() macro.
- In ext4_insert_range(), do the check against s_maxbytes in a way
that is safe against signed overflow. (This doesn't currently matter
for ext4 due to ext4's limited max file size, but this is something
other filesystems have gotten wrong. We might as well do it safely.)
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231180444.46586-3-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Remove the ext4_ind_calc_metadata_amount() and
ext4_ext_calc_metadata_amount() functions, which have been unused since
commit 71d4f7d032 ("ext4: remove metadata reservation checks").
Also remove the i_da_metadata_calc_last_lblock and
i_da_metadata_calc_len fields from struct ext4_inode_info, as these were
only used by these removed functions.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231180444.46586-2-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Since allocating an object from a mempool never fails when
__GFP_DIRECT_RECLAIM (which is included in GFP_NOFS) is set, the check
for failure to allocate a bio_post_read_ctx is unnecessary. Remove it.
Also remove the redundant assignment to ->bi_private.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231181256.47770-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Without any form of coordination, any case where multiple allocations
from the same mempool are needed at a time to make forward progress can
deadlock under memory pressure.
This is the case for struct bio_post_read_ctx, as one can be allocated
to decrypt a Merkle tree page during fsverity_verify_bio(), which itself
is running from a post-read callback for a data bio which has its own
struct bio_post_read_ctx.
Fix this by freeing the first bio_post_read_ctx before calling
fsverity_verify_bio(). This works because verity (if enabled) is always
the last post-read step.
This deadlock can be reproduced by trying to read from an encrypted
verity file after reducing NUM_PREALLOC_POST_READ_CTXS to 1 and patching
mempool_alloc() to pretend that pool->alloc() always fails.
Note that since NUM_PREALLOC_POST_READ_CTXS is actually 128, to actually
hit this bug in practice would require reading from lots of encrypted
verity files at the same time. But it's theoretically possible, as N
available objects isn't enough to guarantee forward progress when > N/2
threads each need 2 objects at a time.
Fixes: 22cfe4b48c ("ext4: add fs-verity read support")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231181222.47684-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4_writepages() on an encrypted file has to encrypt the data, but it
can't modify the pagecache pages in-place, so it encrypts the data into
bounce pages and writes those instead. All bounce pages are allocated
from a mempool using GFP_NOFS.
This is not correct use of a mempool, and it can deadlock. This is
because GFP_NOFS includes __GFP_DIRECT_RECLAIM, which enables the "never
fail" mode for mempool_alloc() where a failed allocation will fall back
to waiting for one of the preallocated elements in the pool.
But since this mode is used for all a bio's pages and not just the
first, it can deadlock waiting for pages already in the bio to be freed.
This deadlock can be reproduced by patching mempool_alloc() to pretend
that pool->alloc() always fails (so that it always falls back to the
preallocations), and then creating an encrypted file of size > 128 KiB.
Fix it by only using GFP_NOFS for the first page in the bio. For
subsequent pages just use GFP_NOWAIT, and if any of those fail, just
submit the bio and start a new one.
This will need to be fixed in f2fs too, but that's less straightforward.
Fixes: c9af28fdd4 ("ext4 crypto: don't let data integrity writebacks fail with ENOMEM")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231181149.47619-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
For encrypted files, commit 36086d43f6 ("ext4 crypto: fix bugs in
ext4_encrypted_zeroout()") disabled the optimization where when a write
occurs to the middle of an unwritten extent, the head and/or tail of the
extent (when they aren't too large) are zeroed out, turned into an
initialized extent, and merged with the part being written to. This
optimization helps prevent fragmentation of the extent tree.
However, disabling this optimization also made fscrypt_zeroout_range()
nearly impossible to test, as now it's only reachable via the very rare
case in ext4_split_extent_at() where allocating a new extent tree block
fails due to ENOSPC. 'gce-xfstests -c ext4/encrypt -g auto' doesn't
even hit this at all.
It's preferable to avoid really rare cases that are hard to test.
That commit also cited data corruption in xfstest generic/127 as a
reason to disable the extent zeroout optimization, but that's no longer
reproducible anymore. It also cited fscrypt_zeroout_range() having poor
performance, but I've written a patch to fix that.
Therefore, re-enable the extent zeroout optimization on encrypted files.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191226161114.53606-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
fscrypt_zeroout_range() is only for encrypted regular files, not for
encrypted directories or symlinks.
Fortunately, currently it seems it's never called on non-regular files.
But to be safe ext4 should explicitly check S_ISREG() before calling it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191226161022.53490-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When ext4 encryption support was first added, ZERO_RANGE was disallowed,
supposedly because test failures (e.g. ext4/001) were seen when enabling
it, and at the time there wasn't enough time/interest to debug it.
However, there's actually no reason why ZERO_RANGE can't work on
encrypted files. And it fact it *does* work now. Whole blocks in the
zeroed range are converted to unwritten extents, as usual; encryption
makes no difference for that part. Partial blocks are zeroed in the
pagecache and then ->writepages() encrypts those blocks as usual.
ext4_block_zero_page_range() handles reading and decrypting the block if
needed before actually doing the pagecache write.
Also, f2fs has always supported ZERO_RANGE on encrypted files.
As far as I can tell, the reason that ext4/001 was failing in v4.1 was
actually because of one of the bugs fixed by commit 36086d43f6 ("ext4
crypto: fix bugs in ext4_encrypted_zeroout()"). The bug made
ext4_encrypted_zeroout() always return a positive value, which caused
unwritten extents in encrypted files to sometimes not be marked as
initialized after being written to. This bug was not actually in
ZERO_RANGE; it just happened to trigger during the extents manipulation
done in ext4/001 (and probably other tests too).
So, let's enable ZERO_RANGE on encrypted files on ext4.
Tested with:
gce-xfstests -c ext4/encrypt -g auto
gce-xfstests -c ext4/encrypt_1k -g auto
Got the same set of test failures both with and without this patch.
But with this patch 6 fewer tests are skipped: ext4/001, generic/008,
generic/009, generic/033, generic/096, and generic/511.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191226154216.4808-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
fscrypt_decrypt_pagecache_blocks() can fail, because it uses
skcipher_request_alloc(), which uses kmalloc(), which can fail; and also
because it calls crypto_skcipher_decrypt(), which can fail depending on
the driver that actually implements the crypto.
Therefore it's not appropriate to WARN on decryption error in
__ext4_block_zero_page_range().
Remove the WARN and just handle the error instead.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191226154105.4704-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since EXT3_FS already selects EXT4_FS, there's no reason for it to
redundantly select all the selections of EXT4_FS -- notwithstanding the
comments that claim otherwise.
Remove these redundant selections to avoid confusion.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191226153920.4466-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Determining an inode's journaling mode has gotten more complicated over
time. Move ext4_inode_journal_mode() from an inline function into
ext4_jbd2.c to reduce the compiled code size.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191209233602.117778-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
The ifdefs for CONFIG_FS_ENCRYPTION in htree_dirblock_to_tree() are
unnecessary, as the called functions are already stubbed out when
!CONFIG_FS_ENCRYPTION. Remove them.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191209213225.18477-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>