01 Mar, 2020
1 commit
-
journal_head::b_transaction and journal_head::b_next_transaction could
be accessed concurrently as noticed by KCSAN,LTP: starting fsync04
/dev/zero: Can't open blockdev
EXT4-fs (loop0): mounting ext3 file system using the ext4 subsystem
EXT4-fs (loop0): mounted filesystem with ordered data mode. Opts: (null)
==================================================================
BUG: KCSAN: data-race in __jbd2_journal_refile_buffer [jbd2] / jbd2_write_access_granted [jbd2]write to 0xffff99f9b1bd0e30 of 8 bytes by task 25721 on cpu 70:
__jbd2_journal_refile_buffer+0xdd/0x210 [jbd2]
__jbd2_journal_refile_buffer at fs/jbd2/transaction.c:2569
jbd2_journal_commit_transaction+0x2d15/0x3f20 [jbd2]
(inlined by) jbd2_journal_commit_transaction at fs/jbd2/commit.c:1034
kjournald2+0x13b/0x450 [jbd2]
kthread+0x1cd/0x1f0
ret_from_fork+0x27/0x50read to 0xffff99f9b1bd0e30 of 8 bytes by task 25724 on cpu 68:
jbd2_write_access_granted+0x1b2/0x250 [jbd2]
jbd2_write_access_granted at fs/jbd2/transaction.c:1155
jbd2_journal_get_write_access+0x2c/0x60 [jbd2]
__ext4_journal_get_write_access+0x50/0x90 [ext4]
ext4_mb_mark_diskspace_used+0x158/0x620 [ext4]
ext4_mb_new_blocks+0x54f/0xca0 [ext4]
ext4_ind_map_blocks+0xc79/0x1b40 [ext4]
ext4_map_blocks+0x3b4/0x950 [ext4]
_ext4_get_block+0xfc/0x270 [ext4]
ext4_get_block+0x3b/0x50 [ext4]
__block_write_begin_int+0x22e/0xae0
__block_write_begin+0x39/0x50
ext4_write_begin+0x388/0xb50 [ext4]
generic_perform_write+0x15d/0x290
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+0x91/0xb05
entry_SYSCALL_64_after_hwframe+0x49/0xbe5 locks held by fsync04/25724:
#0: ffff99f9911093f8 (sb_writers#13){.+.+}, at: vfs_write+0x21c/0x260
#1: ffff99f9db4c0348 (&sb->s_type->i_mutex_key#15){+.+.}, at: ext4_buffered_write_iter+0x65/0x210 [ext4]
#2: ffff99f5e7dfcf58 (jbd2_handle){++++}, at: start_this_handle+0x1c1/0x9d0 [jbd2]
#3: ffff99f9db4c0168 (&ei->i_data_sem){++++}, at: ext4_map_blocks+0x176/0x950 [ext4]
#4: ffffffff99086b40 (rcu_read_lock){....}, at: jbd2_write_access_granted+0x4e/0x250 [jbd2]
irq event stamp: 1407125
hardirqs last enabled at (1407125): [] __find_get_block+0x107/0x790
hardirqs last disabled at (1407124): [] __find_get_block+0x49/0x790
softirqs last enabled at (1405528): [] __do_softirq+0x34c/0x57c
softirqs last disabled at (1405521): [] irq_exit+0xa2/0xc0Reported by Kernel Concurrency Sanitizer on:
CPU: 68 PID: 25724 Comm: fsync04 Tainted: G L 5.6.0-rc2-next-20200221+ #7
Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019The plain reads are outside of jh->b_state_lock critical section which result
in data races. Fix them by adding pairs of READ|WRITE_ONCE().Reviewed-by: Jan Kara
Signed-off-by: Qian Cai
Link: https://lore.kernel.org/r/20200222043111.2227-1-cai@lca.pw
Signed-off-by: Theodore Ts'o
22 Feb, 2020
1 commit
-
I found a NULL pointer dereference in ocfs2_block_group_clear_bits().
The running environment:
kernel version: 4.19
A cluster with two nodes, 5 luns mounted on two nodes, and do some
file operations like dd/fallocate/truncate/rm on every lun with storage
network disconnection.The fallocate operation on dm-23-45 caused an null pointer dereference.
The information of NULL pointer dereference as follows:
[577992.878282] JBD2: Error -5 detected when updating journal superblock for dm-23-45.
[577992.878290] Aborting journal on device dm-23-45.
...
[577992.890778] JBD2: Error -5 detected when updating journal superblock for dm-24-46.
[577992.890908] __journal_remove_journal_head: freeing b_committed_data
[577992.890916] (fallocate,88392,52):ocfs2_extend_trans:474 ERROR: status = -30
[577992.890918] __journal_remove_journal_head: freeing b_committed_data
[577992.890920] (fallocate,88392,52):ocfs2_rotate_tree_right:2500 ERROR: status = -30
[577992.890922] __journal_remove_journal_head: freeing b_committed_data
[577992.890924] (fallocate,88392,52):ocfs2_do_insert_extent:4382 ERROR: status = -30
[577992.890928] (fallocate,88392,52):ocfs2_insert_extent:4842 ERROR: status = -30
[577992.890928] __journal_remove_journal_head: freeing b_committed_data
[577992.890930] (fallocate,88392,52):ocfs2_add_clusters_in_btree:4947 ERROR: status = -30
[577992.890933] __journal_remove_journal_head: freeing b_committed_data
[577992.890939] __journal_remove_journal_head: freeing b_committed_data
[577992.890949] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
[577992.890950] Mem abort info:
[577992.890951] ESR = 0x96000004
[577992.890952] Exception class = DABT (current EL), IL = 32 bits
[577992.890952] SET = 0, FnV = 0
[577992.890953] EA = 0, S1PTW = 0
[577992.890954] Data abort info:
[577992.890955] ISV = 0, ISS = 0x00000004
[577992.890956] CM = 0, WnR = 0
[577992.890958] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f8da07a9
[577992.890960] [0000000000000020] pgd=0000000000000000
[577992.890964] Internal error: Oops: 96000004 [#1] SMP
[577992.890965] Process fallocate (pid: 88392, stack limit = 0x00000000013db2fd)
[577992.890968] CPU: 52 PID: 88392 Comm: fallocate Kdump: loaded Tainted: G W OE 4.19.36 #1
[577992.890969] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019
[577992.890971] pstate: 60400009 (nZCv daif +PAN -UAO)
[577992.891054] pc : _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
[577992.891082] lr : _ocfs2_free_suballoc_bits+0x618/0x968 [ocfs2]
[577992.891084] sp : ffff0000c8e2b810
[577992.891085] x29: ffff0000c8e2b820 x28: 0000000000000000
[577992.891087] x27: 00000000000006f3 x26: ffffa07957b02e70
[577992.891089] x25: ffff807c59d50000 x24: 00000000000006f2
[577992.891091] x23: 0000000000000001 x22: ffff807bd39abc30
[577992.891093] x21: ffff0000811d9000 x20: ffffa07535d6a000
[577992.891097] x19: ffff000001681638 x18: ffffffffffffffff
[577992.891098] x17: 0000000000000000 x16: ffff000080a03df0
[577992.891100] x15: ffff0000811d9708 x14: 203d207375746174
[577992.891101] x13: 73203a524f525245 x12: 20373439343a6565
[577992.891103] x11: 0000000000000038 x10: 0101010101010101
[577992.891106] x9 : ffffa07c68a85d70 x8 : 7f7f7f7f7f7f7f7f
[577992.891109] x7 : 0000000000000000 x6 : 0000000000000080
[577992.891110] x5 : 0000000000000000 x4 : 0000000000000002
[577992.891112] x3 : ffff000001713390 x2 : 2ff90f88b1c22f00
[577992.891114] x1 : ffff807bd39abc30 x0 : 0000000000000000
[577992.891116] Call trace:
[577992.891139] _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
[577992.891162] _ocfs2_free_clusters+0x100/0x290 [ocfs2]
[577992.891185] ocfs2_free_clusters+0x50/0x68 [ocfs2]
[577992.891206] ocfs2_add_clusters_in_btree+0x198/0x5e0 [ocfs2]
[577992.891227] ocfs2_add_inode_data+0x94/0xc8 [ocfs2]
[577992.891248] ocfs2_extend_allocation+0x1bc/0x7a8 [ocfs2]
[577992.891269] ocfs2_allocate_extents+0x14c/0x338 [ocfs2]
[577992.891290] __ocfs2_change_file_space+0x3f8/0x610 [ocfs2]
[577992.891309] ocfs2_fallocate+0xe4/0x128 [ocfs2]
[577992.891316] vfs_fallocate+0x11c/0x250
[577992.891317] ksys_fallocate+0x54/0x88
[577992.891319] __arm64_sys_fallocate+0x28/0x38
[577992.891323] el0_svc_common+0x78/0x130
[577992.891325] el0_svc_handler+0x38/0x78
[577992.891327] el0_svc+0x8/0xcMy analysis process as follows:
ocfs2_fallocate
__ocfs2_change_file_space
ocfs2_allocate_extents
ocfs2_extend_allocation
ocfs2_add_inode_data
ocfs2_add_clusters_in_btree
ocfs2_insert_extent
ocfs2_do_insert_extent
ocfs2_rotate_tree_right
ocfs2_extend_rotate_transaction
ocfs2_extend_trans
jbd2_journal_restart
jbd2__journal_restart
/* handle->h_transaction is NULL,
* is_handle_aborted(handle) is true
*/
handle->h_transaction = NULL;
start_this_handle
return -EROFS;
ocfs2_free_clusters
_ocfs2_free_clusters
_ocfs2_free_suballoc_bits
ocfs2_block_group_clear_bits
ocfs2_journal_access_gd
__ocfs2_journal_access
jbd2_journal_get_undo_access
/* I think jbd2_write_access_granted() will
* return true, because do_get_write_access()
* will return -EROFS.
*/
if (jbd2_write_access_granted(...)) return 0;
do_get_write_access
/* handle->h_transaction is NULL, it will
* return -EROFS here, so do_get_write_access()
* was not called.
*/
if (is_handle_aborted(handle)) return -EROFS;
/* bh2jh(group_bh) is NULL, caused NULL
pointer dereference */
undo_bg = (struct ocfs2_group_desc *)
bh2jh(group_bh)->b_committed_data;If handle->h_transaction == NULL, then jbd2_write_access_granted()
does not really guarantee that journal_head will stay around,
not even speaking of its b_committed_data. The bh2jh(group_bh)
can be removed after ocfs2_journal_access_gd() and before call
"bh2jh(group_bh)->b_committed_data". So, we should move
is_handle_aborted() check from do_get_write_access() into
jbd2_journal_get_undo_access() and jbd2_journal_get_write_access()
before the call to jbd2_write_access_granted().Link: https://lore.kernel.org/r/f72a623f-b3f1-381a-d91d-d22a1c83a336@huawei.com
Signed-off-by: Yan Wang
Signed-off-by: Theodore Ts'o
Reviewed-by: Jun Piao
Reviewed-by: Jan Kara
Cc: stable@kernel.org
17 Feb, 2020
1 commit
-
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
14 Feb, 2020
2 commits
-
Commit 904cdbd41d74 ("jbd2: clear dirty flag when revoking a buffer from
an older transaction") set the BH_Freed flag when forgetting a metadata
buffer which belongs to the committing transaction, it indicate the
committing process clear dirty bits when it is done with the buffer. But
it also clear the BH_Mapped flag at the same time, which may trigger
below NULL pointer oops when block_size < PAGE_SIZE.rmdir 1 kjournald2 mkdir 2
jbd2_journal_commit_transaction
commit transaction N
jbd2_journal_forget
set_buffer_freed(bh1)
jbd2_journal_commit_transaction
commit transaction N+1
...
clear_buffer_mapped(bh1)
ext4_getblk(bh2 ummapped)
...
grow_dev_page
init_page_buffers
bh1->b_private=NULL
bh2->b_private=NULL
jbd2_journal_put_journal_head(jh1)
__journal_remove_journal_head(hb1)
jh1 is NULL and trigger oops*) Dir entry block bh1 and bh2 belongs to one page, and the bh2 has
already been unmapped.For the metadata buffer we forgetting, we should always keep the mapped
flag and clear the dirty flags is enough, so this patch pick out the
these buffers and keep their BH_Mapped flag.Link: https://lore.kernel.org/r/20200213063821.30455-3-yi.zhang@huawei.com
Fixes: 904cdbd41d74 ("jbd2: clear dirty flag when revoking a buffer from an older transaction")
Reviewed-by: Jan Kara
Signed-off-by: zhangyi (F)
Signed-off-by: Theodore Ts'o
Cc: stable@kernel.org -
There is no need to delay the clearing of b_modified flag to the
transaction committing time when unmapping the journalled buffer, so
just move it to the journal_unmap_buffer().Link: https://lore.kernel.org/r/20200213063821.30455-2-yi.zhang@huawei.com
Reviewed-by: Jan Kara
Signed-off-by: zhangyi (F)
Signed-off-by: Theodore Ts'o
Cc: stable@kernel.org
09 Feb, 2020
1 commit
-
Pull misc vfs updates from Al Viro:
- bmap series from cmaiolino
- getting rid of convolutions in copy_mount_options() (use a couple of
copy_from_user() instead of the __get_user() crap)* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
saner copy_mount_options()
fibmap: Reject negative block numbers
fibmap: Use bmap instead of ->bmap method in ioctl_fibmap
ecryptfs: drop direct calls to ->bmap
cachefiles: drop direct usage of ->bmap method.
fs: Enable bmap() function to properly return errors
04 Feb, 2020
1 commit
-
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.Conversion rule is:
llseek => proc_lseek
unlocked_ioctl => proc_ioctlxxx => proc_xxx
delete ".owner = THIS_MODULE" line
[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2
Signed-off-by: Alexey Dobriyan
Signed-off-by: Stephen Rothwell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Feb, 2020
1 commit
-
By now, bmap() will either return the physical block number related to
the requested file offset or 0 in case of error or the requested offset
maps into a hole.
This patch makes the needed changes to enable bmap() to proper return
errors, using the return value as an error return, and now, a pointer
must be passed to bmap() to be filled with the mapped physical block.It will change the behavior of bmap() on return:
- negative value in case of error
- zero on success or map fell into a holeIn case of a hole, the *block will be zero too
Since this is a prep patch, by now, the only error return is -EINVAL if
->bmap doesn't exist.Reviewed-by: Christoph Hellwig
Signed-off-by: Carlos Maiolino
Signed-off-by: Al Viro
25 Jan, 2020
8 commits
-
__jbd2_journal_abort_hard() is no longer used, so now we can merge
__jbd2_journal_abort_hard() and __journal_abort_soft() these two
functions into jbd2_journal_abort() and remove them.Signed-off-by: zhangyi (F)
Reviewed-by: Jan Kara
Link: https://lore.kernel.org/r/20191204124614.45424-5-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o -
Commit fb7c02445c49 ("ext4: pass -ESHUTDOWN code to jbd2 layer") want
to allow jbd2 layer to distinguish shutdown journal abort from other
error cases. So the ESHUTDOWN should be taken precedence over any other
errno which has already been recoded after EXT4_FLAGS_SHUTDOWN is set,
but it only update errno in the journal suoerblock now if the old errno
is 0.Fixes: fb7c02445c49 ("ext4: pass -ESHUTDOWN code to jbd2 layer")
Signed-off-by: zhangyi (F)
Reviewed-by: Jan Kara
Link: https://lore.kernel.org/r/20191204124614.45424-4-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o -
JBD2_REC_ERR flag used to indicate the errno has been updated when jbd2
aborted, and then __ext4_abort() and ext4_handle_error() can invoke
panic if ERRORS_PANIC is specified. But if the journal has been aborted
with zero errno, jbd2_journal_abort() didn't set this flag so we can
no longer panic. Fix this by always record the proper errno in the
journal superblock.Fixes: 4327ba52afd03 ("ext4, jbd2: ensure entering into panic after recording an error in superblock")
Signed-off-by: zhangyi (F)
Reviewed-by: Jan Kara
Link: https://lore.kernel.org/r/20191204124614.45424-3-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o -
We invoke jbd2_journal_abort() to abort the journal and record errno
in the jbd2 superblock when committing journal transaction besides the
failure on submitting the commit record. But there is no need for the
case and we can also invoke jbd2_journal_abort() instead of
__jbd2_journal_abort_hard().Fixes: 818d276ceb83a ("ext4: Add the journal checksum feature")
Signed-off-by: zhangyi (F)
Reviewed-by: Jan Kara
Link: https://lore.kernel.org/r/20191204124614.45424-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o -
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.Script below generates endless output
$ q=;while read -r r;do echo "$((++q)) $r";done
Reviewed-by: Jan Kara
Link: https://lore.kernel.org/r/d13805e5-695e-8ac3-b678-26ca2313629f@virtuozzo.com
Signed-off-by: Theodore Ts'o -
Only when jh->b_jcount = 0 in jbd2_journal_put_journal_head, we are allowed
to call __journal_remove_journal_head. This assertion is meaningless,
just remove it.Signed-off-by: Shijie Luo
Reviewed-by: Jan Kara
Link: https://lore.kernel.org/r/20200123070054.50585-1-luoshijie1@huawei.com
Signed-off-by: Theodore Ts'o -
Fix comment and remove unneccessary blank.
Signed-off-by: Shijie Luo
Reviewed-by: Jan Kara
Link: https://lore.kernel.org/r/20200123064325.36358-1-luoshijie1@huawei.com
Signed-off-by: Theodore Ts'o -
Delete the duplicated words "is" in the comments
Signed-off-by: Yan Wang
Reviewed-by: Jan Kara
Link: https://lore.kernel.org/r/12087f77-ab4d-c7ba-53b4-893dbf0026f0@huawei.com
Signed-off-by: Theodore Ts'o
18 Jan, 2020
1 commit
-
If the journal is dirty when the filesystem is mounted, jbd2 will replay
the journal but the journal superblock will not be updated by
journal_reset() because JBD2_ABORT flag is still set (it was set in
journal_init_common()). This is problematic because when a new transaction
is then committed, it will be recorded in block 1 (journal->j_tail was set
to 1 in journal_reset()). If unclean shutdown happens again before the
journal superblock is updated, the new recorded transaction will not be
replayed during the next mount (because of stale sb->s_start and
sb->s_sequence values) which can lead to filesystem corruption.Fixes: 85e0c4e89c1b ("jbd2: if the journal is aborted then don't allow update of the log tail")
Signed-off-by: Kai Li
Link: https://lore.kernel.org/r/20200111022542.5008-1-li.kai4@h3c.com
Signed-off-by: Theodore Ts'o
01 Dec, 2019
1 commit
-
Pull ext4 updates from Ted Ts'o:
"This merge window saw the the following new featuers added to ext4:- Direct I/O via iomap (required the iomap-for-next branch from
Darrick as a prereq).- Support for using dioread-nolock where the block size < page size.
- Support for encryption for file systems where the block size < page
size.- Rework of journal credits handling so a revoke-heavy workload will
not cause the journal to run out of space.- Replace bit-spinlocks with spinlocks in jbd2
Also included were some bug fixes and cleanups, mostly to clean up
corner cases from fuzzed file systems and error path handling"* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (59 commits)
ext4: work around deleting a file with i_nlink == 0 safely
ext4: add more paranoia checking in ext4_expand_extra_isize handling
jbd2: make jbd2_handle_buffer_credits() handle reserved handles
ext4: fix a bug in ext4_wait_for_tail_page_commit
ext4: bio_alloc with __GFP_DIRECT_RECLAIM never fails
ext4: code cleanup for get_next_id
ext4: fix leak of quota reservations
ext4: remove unused variable warning in parse_options()
ext4: Enable encryption for subpage-sized blocks
fs/buffer.c: support fscrypt in block_read_full_page()
ext4: Add error handling for io_end_vec struct allocation
jbd2: Fine tune estimate of necessary descriptor blocks
jbd2: Provide trace event for handle restarts
ext4: Reserve revoke credits for freed blocks
jbd2: Make credit checking more strict
jbd2: Rename h_buffer_credits to h_total_credits
jbd2: Reserve space for revoke descriptor blocks
jbd2: Drop jbd2_space_needed()
jbd2: Account descriptor blocks into t_outstanding_credits
jbd2: Factor out common parts of stopping and restarting a handle
...
06 Nov, 2019
15 commits
-
Currently we reserve j_max_transaction_buffers / 32 for transaction
descriptor blocks. Now that revoke descriptors are accounted for
separately this estimate is unnecessarily high and we can actually
compute much tighter estimate. In the common case of 32k journal blocks
and 4k blocksize this actually reduces the amount of reserved descriptor
blocks from 256 to ~25 which allows us to fit more real data into a
transaction.Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-25-jack@suse.cz
Signed-off-by: Theodore Ts'o -
Provide trace event for handle restarts to ease debugging.
Reviewed-by: Theodore Ts'o
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-24-jack@suse.cz
Signed-off-by: Theodore Ts'o -
Make checking of available credits in jbd2_journal_dirty_metadata() more
strict. There should be always enough credits in the handle to write all
potential revoke descriptors. Also we warn in case there are not enough
credits since this is a bug in the filesystem.Reviewed-by: Theodore Ts'o
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-22-jack@suse.cz
Signed-off-by: Theodore Ts'o -
The credit counter now contains both buffer and revoke descriptor block
credits. Rename to counter to h_total_credits to reflect that. No
functional change.Reviewed-by: Theodore Ts'o
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-21-jack@suse.cz
Signed-off-by: Theodore Ts'o -
Extend functions for starting, extending, and restarting transaction
handles to take number of revoke records handle must be able to
accommodate. These functions then make sure transaction has enough
credits to be able to store resulting revoke descriptor blocks. Also
revoke code tracks number of revoke records created by a handle to catch
situation where some place didn't reserve enough space for revoke
records. Similarly to standard transaction credits, space for unused
reserved revoke records is released when the handle is stopped.On the ext4 side we currently take a simplistic approach of reserving
space for 1024 revoke records for any transaction. This grows amount of
credits reserved for each handle only by a few and is enough for any
normal workload so that we don't hit warnings in jbd2. We will refine
the logic in following commits.Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-20-jack@suse.cz
Signed-off-by: Theodore Ts'o -
The function is now just a trivial wrapper returning
journal->j_max_transaction_buffers. Drop it.Reviewed-by: Theodore Ts'o
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-19-jack@suse.cz
Signed-off-by: Theodore Ts'o -
Currently, journal descriptor blocks were not accounted in
transaction->t_outstanding_credits and we were just leaving some slack
space in the journal for them (in jbd2_log_space_left() and
jbd2_space_needed()). This is making proper accounting (and reservation
we want to add) of descriptor blocks difficult so switch to accounting
descriptor blocks in transaction->t_outstanding_credits and just reserve
the same amount of credits in t_outstanding credits for journal
descriptor blocks when creating transaction.Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-18-jack@suse.cz
Signed-off-by: Theodore Ts'o -
jbd2__journal_restart() has quite some code that is common with
jbd2_journal_stop(). Factor this functionality into stop_this_handle()
helper and use it from both functions. Note that this also drops
t_handle_lock protection from jbd2__journal_restart() as
jbd2_journal_stop() does the same thing without it.Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-17-jack@suse.cz
Signed-off-by: Theodore Ts'o -
When we drop last handle from a transaction and journal->j_barrier_count
> 0, jbd2_journal_stop() wakes up journal->j_wait_transaction_locked
wait queue. This looks pointless - wait for outstanding handles always
happens on journal->j_wait_updates waitqueue.
journal->j_wait_transaction_locked is used to wait for transaction state
changes and by start_this_handle() for waiting until
journal->j_barrier_count drops to 0. The first case is clearly
irrelevant here since only jbd2 thread changes transaction state. The
second case looks related but jbd2_journal_unlock_updates() is
responsible for the wakeup in this case. So just drop the wakeup.Reviewed-by: Theodore Ts'o
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-16-jack@suse.cz
Signed-off-by: Theodore Ts'o -
If a transaction is larger than journal->j_max_transaction_buffers, that
is a bug and not a trigger for transaction commit. Also the very next
attempt to start new handle will start transaction commit anyway. So
just remove the pointless check. Arguably, we could start transaction
commit whenever the transaction size is *close* to
journal->j_max_transaction_buffers. This has a potential to reduce
latency of the next jbd2_journal_start() at the cost of somewhat smaller
transactions. However for this to have any effect, it would mean that
there isn't someone already waiting in jbd2_journal_start() which means
metadata load for the fs is pretty light anyway so probably this
optimization is not worth it.Reviewed-by: Theodore Ts'o
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-15-jack@suse.cz
Signed-off-by: Theodore Ts'o -
Move code in jbd2_journal_stop() around a bit. It removes some
unnecessary code duplication and will make factoring out parts common
with jbd2__journal_restart() easier.Reviewed-by: Theodore Ts'o
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-14-jack@suse.cz
Signed-off-by: Theodore Ts'o -
jbd2 statistics counting number of blocks logged in a transaction was
wrong. It didn't count the commit block and more importantly it didn't
count revoke descriptor blocks. Make sure these get properly counted.Reviewed-by: Theodore Ts'o
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-13-jack@suse.cz
Signed-off-by: Theodore Ts'o -
With 32-bit block numbers, we don't allocate the array for journal
buffer heads large enough for corresponding descriptor tags to fill the
descriptor block. Thus we end up writing out half-full descriptor blocks
to the journal unnecessarily growing the transaction. Fix the logic to
allocate the array large enough.Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-3-jack@suse.cz
Signed-off-by: Theodore Ts'o -
jbd2_journal_next_log_block() does not look at
transaction->t_outstanding_credits. Remove the misleading comment.Reviewed-by: Theodore Ts'o
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20191105164437.32602-2-jack@suse.cz
Signed-off-by: Theodore Ts'o
21 Oct, 2019
6 commits
-
On PREEMPT_RT bit-spinlocks have the same semantics as on PREEMPT_RT=n,
i.e. they disable preemption. That means functions which are not safe to be
called in preempt disabled context on RT trigger a might_sleep() assert.The journal head bit spinlock is mostly held for short code sequences with
trivial RT safe functionality, except for one place:jbd2_journal_put_journal_head() invokes __journal_remove_journal_head()
with the journal head bit spinlock held. __journal_remove_journal_head()
invokes kmem_cache_free() which must not be called with preemption disabled
on RT.Jan suggested to rework the removal function so the actual free happens
outside the bit-spinlocked region.Split it into two parts:
- Do the sanity checks and the buffer head detach under the lock
- Do the actual free after dropping the lock
There is error case handling in the free part which needs to dereference
the b_size field of the now detached buffer head. Due to paranoia (caused
by ignorance) the size is retrieved in the detach function and handed into
the free function. Might be over-engineered, but better safe than sorry.This makes the journal head bit-spinlock usage RT compliant and also avoids
nested locking which is not covered by lockdep.Suggested-by: Jan Kara
Signed-off-by: Thomas Gleixner
Cc: linux-ext4@vger.kernel.org
Cc: "Theodore Ts'o"
Cc: Jan Kara
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20190809124233.13277-8-jack@suse.cz
Signed-off-by: Theodore Ts'o -
Bit-spinlocks are problematic on PREEMPT_RT if functions which might sleep
on RT, e.g. spin_lock(), alloc/free(), are invoked inside the lock held
region because bit spinlocks disable preemption even on RT.A first attempt was to replace state lock with a spinlock placed in struct
buffer_head and make the locking conditional on PREEMPT_RT and
DEBUG_BIT_SPINLOCKS.Jan pointed out that there is a 4 byte hole in struct journal_head where a
regular spinlock fits in and he would not object to convert the state lock
to a spinlock unconditionally.Aside of solving the RT problem, this also gains lockdep coverage for the
journal head state lock (bit-spinlocks are not covered by lockdep as it's
hard to fit a lockdep map into a single bit).The trivial change would have been to convert the jbd_*lock_bh_state()
inlines, but that comes with the downside that these functions take a
buffer head pointer which needs to be converted to a journal head pointer
which adds another level of indirection.As almost all functions which use this lock have a journal head pointer
readily available, it makes more sense to remove the lock helper inlines
and write out spin_*lock() at all call sites.Fixup all locking comments as well.
Suggested-by: Jan Kara
Signed-off-by: Thomas Gleixner
Signed-off-by: Jan Kara
Cc: "Theodore Ts'o"
Cc: Mark Fasheh
Cc: Joseph Qi
Cc: Joel Becker
Cc: Jan Kara
Cc: linux-ext4@vger.kernel.org
Link: https://lore.kernel.org/r/20190809124233.13277-7-jack@suse.cz
Signed-off-by: Theodore Ts'o -
jbd2_journal_forget() jumps to 'not_jbd' branch which calls __bforget()
in cases where the buffer is clean which is pointless. In case of failed
assertion, it can be even argued that it is safer not to touch buffer's
dirty bits. Also logically it makes more sense to just jump to 'drop'
and that will make logic also simpler when we switch bh_state_lock to a
spinlock.Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20190809124233.13277-6-jack@suse.cz
Signed-off-by: Theodore Ts'o -
We have cleared both dirty & jbddirty bits from the bh. So there's no
difference between bforget() and brelse(). Thus there's no point jumping
to no_jbd branch.Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20190809124233.13277-5-jack@suse.cz
Signed-off-by: Theodore Ts'o -
__jbd2_journal_unfile_buffer() and __jbd2_journal_refile_buffer() drop
transaction's jh reference when they remove jh from a transaction. This
will be however inconvenient once we move state lock into journal_head
itself as we still need to unlock it and we'd need to grab jh reference
just for that. Move dropping of jh reference out of these functions into
the few callers.Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20190809124233.13277-4-jack@suse.cz
Signed-off-by: Theodore Ts'o -
journal_unmap_buffer() checks first whether the buffer head is a journal.
If so it takes locks and then invokes jbd2_journal_grab_journal_head()
followed by another check whether this is journal head buffer.The double checking is pointless.
Replace the initial check with jbd2_journal_grab_journal_head() which
alredy checks whether the buffer head is actually a journal.Allows also early access to the journal head pointer for the upcoming
conversion of state lock to a regular spinlock.Signed-off-by: Thomas Gleixner
Reviewed-by: Jan Kara
Cc: linux-ext4@vger.kernel.org
Cc: "Theodore Ts'o"
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20190809124233.13277-2-jack@suse.cz
Signed-off-by: Theodore Ts'o
09 Oct, 2019
1 commit
-
Since the following commit:
b4adfe8e05f1 ("locking/lockdep: Remove unused argument in __lock_release")
@nested is no longer used in lock_release(), so remove it from all
lock_release() calls and friends.Signed-off-by: Qian Cai
Signed-off-by: Peter Zijlstra (Intel)
Acked-by: Will Deacon
Acked-by: Daniel Vetter
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: alexander.levin@microsoft.com
Cc: daniel@iogearbox.net
Cc: davem@davemloft.net
Cc: dri-devel@lists.freedesktop.org
Cc: duyuyang@gmail.com
Cc: gregkh@linuxfoundation.org
Cc: hannes@cmpxchg.org
Cc: intel-gfx@lists.freedesktop.org
Cc: jack@suse.com
Cc: jlbec@evilplan.or
Cc: joonas.lahtinen@linux.intel.com
Cc: joseph.qi@linux.alibaba.com
Cc: jslaby@suse.com
Cc: juri.lelli@redhat.com
Cc: maarten.lankhorst@linux.intel.com
Cc: mark@fasheh.com
Cc: mhocko@kernel.org
Cc: mripard@kernel.org
Cc: ocfs2-devel@oss.oracle.com
Cc: rodrigo.vivi@intel.com
Cc: sean@poorly.run
Cc: st@kernel.org
Cc: tj@kernel.org
Cc: tytso@mit.edu
Cc: vdavydov.dev@gmail.com
Cc: vincent.guittot@linaro.org
Cc: viro@zeniv.linux.org.uk
Link: https://lkml.kernel.org/r/1568909380-32199-1-git-send-email-cai@lca.pw
Signed-off-by: Ingo Molnar