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2022-09-28ext4: use locality group preallocation for small closed filesJan Kara
commit a9f2a2931d0e197ab28c6007966053fdababd53f upstream. Curently we don't use any preallocation when a file is already closed when allocating blocks (from writeback code when converting delayed allocation). However for small files, using locality group preallocation is actually desirable as that is not specific to a particular file. Rather it is a method to pack small files together to reduce fragmentation and for that the fact the file is closed is actually even stronger hint the file would benefit from packing. So change the logic to allow locality group preallocation in this case. Fixes: 196e402adf2e ("ext4: improve cr 0 / cr 1 group scanning") CC: stable@kernel.org Reported-and-tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/all/0d81a7c2-46b7-6010-62a4-3e6cfc1628d6@i2se.com/ Link: https://lore.kernel.org/r/20220908092136.11770-4-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-28ext4: avoid unnecessary spreading of allocations among groupsJan Kara
commit 1940265ede6683f6317cba0d428ce6505eaca944 upstream. mb_set_largest_free_order() updates lists containing groups with largest chunk of free space of given order. The way it updates it leads to always moving the group to the tail of the list. Thus allocations looking for free space of given order effectively end up cycling through all groups (and due to initialization in last to first order). This spreads allocations among block groups which reduces performance for rotating disks or low-end flash media. Change mb_set_largest_free_order() to only update lists if the order of the largest free chunk in the group changed. Fixes: 196e402adf2e ("ext4: improve cr 0 / cr 1 group scanning") CC: stable@kernel.org Reported-and-tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/all/0d81a7c2-46b7-6010-62a4-3e6cfc1628d6@i2se.com/ Link: https://lore.kernel.org/r/20220908092136.11770-2-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-28ext4: make mballoc try target group first even with mb_optimize_scanJan Kara
commit 4fca50d440cc5d4dc570ad5484cc0b70b381bc2a upstream. One of the side-effects of mb_optimize_scan was that the optimized functions to select next group to try were called even before we tried the goal group. As a result we no longer allocate files close to corresponding inodes as well as we don't try to expand currently allocated extent in the same group. This results in reaim regression with workfile.disk workload of upto 8% with many clients on my test machine: baseline mb_optimize_scan Hmean disk-1 2114.16 ( 0.00%) 2099.37 ( -0.70%) Hmean disk-41 87794.43 ( 0.00%) 83787.47 * -4.56%* Hmean disk-81 148170.73 ( 0.00%) 135527.05 * -8.53%* Hmean disk-121 177506.11 ( 0.00%) 166284.93 * -6.32%* Hmean disk-161 220951.51 ( 0.00%) 207563.39 * -6.06%* Hmean disk-201 208722.74 ( 0.00%) 203235.59 ( -2.63%) Hmean disk-241 222051.60 ( 0.00%) 217705.51 ( -1.96%) Hmean disk-281 252244.17 ( 0.00%) 241132.72 * -4.41%* Hmean disk-321 255844.84 ( 0.00%) 245412.84 * -4.08%* Also this is causing huge regression (time increased by a factor of 5 or so) when untarring archive with lots of small files on some eMMC storage cards. Fix the problem by making sure we try goal group first. Fixes: 196e402adf2e ("ext4: improve cr 0 / cr 1 group scanning") CC: stable@kernel.org Reported-and-tested-by: Stefan Wahren <stefan.wahren@i2se.com> Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Link: https://lore.kernel.org/all/20220727105123.ckwrhbilzrxqpt24@quack3/ Link: https://lore.kernel.org/all/0d81a7c2-46b7-6010-62a4-3e6cfc1628d6@i2se.com/ Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20220908092136.11770-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-28ext4: limit the number of retries after discarding preallocations blocksTheodore Ts'o
commit 80fa46d6b9e7b1527bfd2197d75431fd9c382161 upstream. This patch avoids threads live-locking for hours when a large number threads are competing over the last few free extents as they blocks getting added and removed from preallocation pools. From our bug reporter: A reliable way for triggering this has multiple writers continuously write() to files when the filesystem is full, while small amounts of space are freed (e.g. by truncating a large file -1MiB at a time). In the local filesystem, this can be done by simply not checking the return code of write (0) and/or the error (ENOSPACE) that is set. Over NFS with an async mount, even clients with proper error checking will behave this way since the linux NFS client implementation will not propagate the server errors [the write syscalls immediately return success] until the file handle is closed. This leads to a situation where NFS clients send a continuous stream of WRITE rpcs which result in ERRNOSPACE -- but since the client isn't seeing this, the stream of writes continues at maximum network speed. When some space does appear, multiple writers will all attempt to claim it for their current write. For NFS, we may see dozens to hundreds of threads that do this. The real-world scenario of this is database backup tooling (in particular, github.com/mdkent/percona-xtrabackup) which may write large files (>1TiB) to NFS for safe keeping. Some temporary files are written, rewound, and read back -- all before closing the file handle (the temp file is actually unlinked, to trigger automatic deletion on close/crash.) An application like this operating on an async NFS mount will not see an error code until TiB have been written/read. The lockup was observed when running this database backup on large filesystems (64 TiB in this case) with a high number of block groups and no free space. Fragmentation is generally not a factor in this filesystem (~thousands of large files, mostly contiguous except for the parts written while the filesystem is at capacity.) Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-22ext4: fix bug_on ext4_mb_use_inode_paBaokun Li
commit a08f789d2ab5242c07e716baf9a835725046be89 upstream. Hulk Robot reported a BUG_ON: ================================================================== kernel BUG at fs/ext4/mballoc.c:3211! [...] RIP: 0010:ext4_mb_mark_diskspace_used.cold+0x85/0x136f [...] Call Trace: ext4_mb_new_blocks+0x9df/0x5d30 ext4_ext_map_blocks+0x1803/0x4d80 ext4_map_blocks+0x3a4/0x1a10 ext4_writepages+0x126d/0x2c30 do_writepages+0x7f/0x1b0 __filemap_fdatawrite_range+0x285/0x3b0 file_write_and_wait_range+0xb1/0x140 ext4_sync_file+0x1aa/0xca0 vfs_fsync_range+0xfb/0x260 do_fsync+0x48/0xa0 [...] ================================================================== Above issue may happen as follows: ------------------------------------- do_fsync vfs_fsync_range ext4_sync_file file_write_and_wait_range __filemap_fdatawrite_range do_writepages ext4_writepages mpage_map_and_submit_extent mpage_map_one_extent ext4_map_blocks ext4_mb_new_blocks ext4_mb_normalize_request >>> start + size <= ac->ac_o_ex.fe_logical ext4_mb_regular_allocator ext4_mb_simple_scan_group ext4_mb_use_best_found ext4_mb_new_preallocation ext4_mb_new_inode_pa ext4_mb_use_inode_pa >>> set ac->ac_b_ex.fe_len <= 0 ext4_mb_mark_diskspace_used >>> BUG_ON(ac->ac_b_ex.fe_len <= 0); we can easily reproduce this problem with the following commands: `fallocate -l100M disk` `mkfs.ext4 -b 1024 -g 256 disk` `mount disk /mnt` `fsstress -d /mnt -l 0 -n 1000 -p 1` The size must be smaller than or equal to EXT4_BLOCKS_PER_GROUP. Therefore, "start + size <= ac->ac_o_ex.fe_logical" may occur when the size is truncated. So start should be the start position of the group where ac_o_ex.fe_logical is located after alignment. In addition, when the value of fe_logical or EXT4_BLOCKS_PER_GROUP is very large, the value calculated by start_off is more accurate. Cc: stable@kernel.org Fixes: cd648b8a8fd5 ("ext4: trim allocation requests to group size") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20220528110017.354175-2-libaokun1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09ext4: mark group as trimmed only if it was fully scannedDmitry Monakhov
commit d63c00ea435a5352f486c259665a4ced60399421 upstream. Otherwise nonaligned fstrim calls will works inconveniently for iterative scanners, for example: // trim [0,16MB] for group-1, but mark full group as trimmed fstrim -o $((1024*1024*128)) -l $((1024*1024*16)) ./m // handle [16MB,16MB] for group-1, do nothing because group already has the flag. fstrim -o $((1024*1024*144)) -l $((1024*1024*16)) ./m [ Update function documentation for ext4_trim_all_free -- TYT ] Signed-off-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru> Link: https://lore.kernel.org/r/1650214995-860245-1-git-send-email-dmtrmonakhov@yandex-team.ru Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08ext4: fix ext4_mb_mark_bb() with flex_bg with fast_commitRitesh Harjani
[ Upstream commit bfdc502a4a4c058bf4cbb1df0c297761d528f54d ] In case of flex_bg feature (which is by default enabled), extents for any given inode might span across blocks from two different block group. ext4_mb_mark_bb() only reads the buffer_head of block bitmap once for the starting block group, but it fails to read it again when the extent length boundary overflows to another block group. Then in this below loop it accesses memory beyond the block group bitmap buffer_head and results into a data abort. for (i = 0; i < clen; i++) if (!mb_test_bit(blkoff + i, bitmap_bh->b_data) == !state) already++; This patch adds this functionality for checking block group boundary in ext4_mb_mark_bb() and update the buffer_head(bitmap_bh) for every different block group. w/o this patch, I was easily able to hit a data access abort using Power platform. <...> [ 74.327662] EXT4-fs error (device loop3): ext4_mb_generate_buddy:1141: group 11, block bitmap and bg descriptor inconsistent: 21248 vs 23294 free clusters [ 74.533214] EXT4-fs (loop3): shut down requested (2) [ 74.536705] Aborting journal on device loop3-8. [ 74.702705] BUG: Unable to handle kernel data access on read at 0xc00000005e980000 [ 74.703727] Faulting instruction address: 0xc0000000007bffb8 cpu 0xd: Vector: 300 (Data Access) at [c000000015db7060] pc: c0000000007bffb8: ext4_mb_mark_bb+0x198/0x5a0 lr: c0000000007bfeec: ext4_mb_mark_bb+0xcc/0x5a0 sp: c000000015db7300 msr: 800000000280b033 dar: c00000005e980000 dsisr: 40000000 current = 0xc000000027af6880 paca = 0xc00000003ffd5200 irqmask: 0x03 irq_happened: 0x01 pid = 5167, comm = mount <...> enter ? for help [c000000015db7380] c000000000782708 ext4_ext_clear_bb+0x378/0x410 [c000000015db7400] c000000000813f14 ext4_fc_replay+0x1794/0x2000 [c000000015db7580] c000000000833f7c do_one_pass+0xe9c/0x12a0 [c000000015db7710] c000000000834504 jbd2_journal_recover+0x184/0x2d0 [c000000015db77c0] c000000000841398 jbd2_journal_load+0x188/0x4a0 [c000000015db7880] c000000000804de8 ext4_fill_super+0x2638/0x3e10 [c000000015db7a40] c0000000005f8404 get_tree_bdev+0x2b4/0x350 [c000000015db7ae0] c0000000007ef058 ext4_get_tree+0x28/0x40 [c000000015db7b00] c0000000005f6344 vfs_get_tree+0x44/0x100 [c000000015db7b70] c00000000063c408 path_mount+0xdd8/0xe70 [c000000015db7c40] c00000000063c8f0 sys_mount+0x450/0x550 [c000000015db7d50] c000000000035770 system_call_exception+0x4a0/0x4e0 [c000000015db7e10] c00000000000c74c system_call_common+0xec/0x250 Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/2609bc8f66fc15870616ee416a18a3d392a209c4.1644992609.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08ext4: correct cluster len and clusters changed accounting in ext4_mb_mark_bbRitesh Harjani
[ Upstream commit a5c0e2fdf7cea535ba03259894dc184e5a4c2800 ] ext4_mb_mark_bb() currently wrongly calculates cluster len (clen) and flex_group->free_clusters. This patch fixes that. Identified based on code review of ext4_mb_mark_bb() function. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/a0b035d536bafa88110b74456853774b64c8ac40.1644992609.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08ext4: make mb_optimize_scan performance mount option work with extentsOjaswin Mujoo
commit 077d0c2c78df6f7260cdd015a991327efa44d8ad upstream. Currently mb_optimize_scan scan feature which improves filesystem performance heavily (when FS is fragmented), seems to be not working with files with extents (ext4 by default has files with extents). This patch fixes that and makes mb_optimize_scan feature work for files with extents. Below are some performance numbers obtained when allocating a 10M and 100M file with and w/o this patch on a filesytem with no 1M contiguous block. <perf numbers> =============== Workload: dd if=/dev/urandom of=test conv=fsync bs=1M count=10/100 Time taken ===================================================== no. Size without-patch with-patch Diff(%) 1 10M 0m8.401s 0m5.623s 33.06% 2 100M 1m40.465s 1m14.737s 25.6% <debug stats> ============= w/o patch: mballoc: reqs: 17056 success: 11407 groups_scanned: 13643 cr0_stats: hits: 37 groups_considered: 9472 useless_loops: 36 bad_suggestions: 0 cr1_stats: hits: 11418 groups_considered: 908560 useless_loops: 1894 bad_suggestions: 0 cr2_stats: hits: 1873 groups_considered: 6913 useless_loops: 21 cr3_stats: hits: 21 groups_considered: 5040 useless_loops: 21 extents_scanned: 417364 goal_hits: 3707 2^n_hits: 37 breaks: 1873 lost: 0 buddies_generated: 239/240 buddies_time_used: 651080 preallocated: 705 discarded: 478 with patch: mballoc: reqs: 12768 success: 11305 groups_scanned: 12768 cr0_stats: hits: 1 groups_considered: 18 useless_loops: 0 bad_suggestions: 0 cr1_stats: hits: 5829 groups_considered: 50626 useless_loops: 0 bad_suggestions: 0 cr2_stats: hits: 6938 groups_considered: 580363 useless_loops: 0 cr3_stats: hits: 0 groups_considered: 0 useless_loops: 0 extents_scanned: 309059 goal_hits: 0 2^n_hits: 1 breaks: 1463 lost: 0 buddies_generated: 239/240 buddies_time_used: 791392 preallocated: 673 discarded: 446 Fixes: 196e402 (ext4: improve cr 0 / cr 1 group scanning) Cc: stable@kernel.org Reported-by: Geetika Moolchandani <Geetika.Moolchandani1@ibm.com> Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com> Suggested-by: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://lore.kernel.org/r/fc9a48f7f8dcfc83891a8b21f6dd8cdf056ed810.1646732698.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-08ext4: modify the logic of ext4_mb_new_blocks_simpleXin Yin
commit 31a074a0c62dc0d2bfb9b543142db4fe27f9e5eb upstream. For now in ext4_mb_new_blocks_simple, if we found a block which should be excluded then will switch to next group, this may probably cause 'group' run out of range. Change to check next block in the same group when get a block should be excluded. Also change the search range to EXT4_CLUSTERS_PER_GROUP and add error checking. Signed-off-by: Xin Yin <yinxin.x@bytedance.com> Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20220110035141.1980-3-yinxin.x@bytedance.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27ext4: fix a possible ABBA deadlock due to busy PAChunguang Xu
commit 8c80fb312d7abf8bcd66cca1d843a80318a2c522 upstream. We found on older kernel (3.10) that in the scenario of insufficient disk space, system may trigger an ABBA deadlock problem, it seems that this problem still exists in latest kernel, try to fix it here. The main process triggered by this problem is that task A occupies the PA and waits for the jbd2 transaction finish, the jbd2 transaction waits for the completion of task B's IO (plug_list), but task B waits for the release of PA by task A to finish discard, which indirectly forms an ABBA deadlock. The related calltrace is as follows: Task A vfs_write ext4_mb_new_blocks() ext4_mb_mark_diskspace_used() JBD2 jbd2_journal_get_write_access() -> jbd2_journal_commit_transaction() ->schedule() filemap_fdatawait() | | | Task B | | do_unlinkat() | | ext4_evict_inode() | | jbd2_journal_begin_ordered_truncate() | | filemap_fdatawrite_range() | | ext4_mb_new_blocks() | -ext4_mb_discard_group_preallocations() <----- Here, try to cancel ext4_mb_discard_group_preallocations() internal retry due to PA busy, and do a limited number of retries inside ext4_mb_discard_preallocations(), which can circumvent the above problems, but also has some advantages: 1. Since the PA is in a busy state, if other groups have free PAs, keeping the current PA may help to reduce fragmentation. 2. Continue to traverse forward instead of waiting for the current group PA to be released. In most scenarios, the PA discard time can be reduced. However, in the case of smaller free space, if only a few groups have space, then due to multiple traversals of the group, it may increase CPU overhead. But in contrast, I feel that the overall benefit is better than the cost. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reported-by: kernel test robot <lkp@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/1637630277-23496-1-git-send-email-brookxu.cn@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27ext4: avoid trim error on fs with small groupsJan Kara
[ Upstream commit 173b6e383d2a204c9921ffc1eca3b87aa2106c33 ] A user reported FITRIM ioctl failing for him on ext4 on some devices without apparent reason. After some debugging we've found out that these devices (being LVM volumes) report rather large discard granularity of 42MB and the filesystem had 1k blocksize and thus group size of 8MB. Because ext4 FITRIM implementation puts discard granularity into minlen, ext4_trim_fs() declared the trim request as invalid. However just silently doing nothing seems to be a more appropriate reaction to such combination of parameters since user did not specify anything wrong. CC: Lukas Czerner <lczerner@redhat.com> Fixes: 5c2ed62fd447 ("ext4: Adjust minlen with discard_granularity in the FITRIM ioctl") Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20211112152202.26614-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-30ext4: Support for checksumming from journal triggersJan Kara
JBD2 layer support triggers which are called when journaling layer moves buffer to a certain state. We can use the frozen trigger, which gets called when buffer data is frozen and about to be written out to the journal, to compute block checksums for some buffer types (similarly as does ocfs2). This avoids unnecessary repeated recomputation of the checksum (at the cost of larger window where memory corruption won't be caught by checksumming) and is even necessary when there are unsynchronized updaters of the checksummed data. So add superblock and journal trigger type arguments to ext4_journal_get_write_access() and ext4_journal_get_create_access() so that frozen triggers can be set accordingly. Also add inode argument to ext4_walk_page_buffers() and all the callbacks used with that function for the same purpose. This patch is mostly only a change of prototype of the above mentioned functions and a few small helpers. Real checksumming will come later. Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210816095713.16537-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-30ext4: fix sparse warningsTheodore Ts'o
Add sparse annotations to suppress false positive context imbalance warnings, and use NULL instead of 0 in EXT_MAX_{EXTENT,INDEX}. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-30ext4: flush background discard kwork when retry allocationWang Jianchao
The background discard kwork tries to mark blocks used and issue discard. This can make filesystem suffer from NOSPC error, xfstest generic/371 can fail due to it. Fix it by flushing discard kwork in ext4_should_retry_alloc. At the same time, give up discard at the moment. Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com> Link: https://lore.kernel.org/r/20210830075246.12516-6-jianchao.wan9@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-30ext4: get discard out of jbd2 commit kthread contexWang Jianchao
Right now, discard is issued and waited to be completed in jbd2 commit kthread context after the logs are committed. When large amount of files are deleted and discard is flooding, jbd2 commit kthread can be blocked for long time. Then all of the metadata operations can be blocked to wait the log space. One case is the page fault path with read mm->mmap_sem held, which wants to update the file time but has to wait for the log space. When other threads in the task wants to do mmap, then write mmap_sem is blocked. Finally all of the following read mmap_sem requirements are blocked, even the ps command which need to read the /proc/pid/ -cmdline. Our monitor service which needs to read /proc/pid/cmdline used to be blocked for 5 mins. This patch frees the blocks back to buddy after commit and then do discard in a async kworker context in fstrim fashion, namely, - mark blocks to be discarded as used if they have not been allocated - do discard - mark them free After this, jbd2 commit kthread won't be blocked any more by discard and we won't get NOSPC even if the discard is slow or throttled. Link: https://marc.info/?l=linux-kernel&m=162143690731901&w=2 Suggested-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com> Link: https://lore.kernel.org/r/20210830075246.12516-5-jianchao.wan9@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-12ext4: remove the repeated comment of ext4_trim_all_freeWang Jianchao
Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210724074124.25731-4-jianchao.wan9@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-12ext4: add new helper interface ext4_try_to_trim_range()Wang Jianchao
There is no functional change in this patch but just split the codes, which serachs free block and does trim, into a new function ext4_try_to_trim_range. This is preparing for the following async backgroup discard. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210724074124.25731-3-jianchao.wan9@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-08-12ext4: remove the 'group' parameter of ext4_trim_extentWang Jianchao
Get rid of the 'group' parameter of ext4_trim_extent as we can get it from the 'e4b'. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Wang Jianchao <wangjianchao@kuaishou.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210724074124.25731-2-jianchao.wan9@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-07-01ext4: use ext4_grp_locked_error in mb_find_extentStephen Brennan
Commit 5d1b1b3f492f ("ext4: fix BUG when calling ext4_error with locked block group") introduces ext4_grp_locked_error to handle unlocking a group in error cases. Otherwise, there is a possibility of a sleep while atomic. However, since 43c73221b3b1 ("ext4: replace BUG_ON with WARN_ON in mb_find_extent()"), mb_find_extent() has contained a ext4_error() call while a group spinlock is held. Replace this with ext4_grp_locked_error. Fixes: 43c73221b3b1 ("ext4: replace BUG_ON with WARN_ON in mb_find_extent()") Cc: <stable@vger.kernel.org> # 4.14+ Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Reviewed-by: Lukas Czerner <lczerner@redhat.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Link: https://lore.kernel.org/r/20210623232114.34457-1-stephen.s.brennan@oracle.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-05-20ext4: fix memory leak in ext4_mb_init_backend on error path.Phillip Potter
Fix a memory leak discovered by syzbot when a file system is corrupted with an illegally large s_log_groups_per_flex. Reported-by: syzbot+aa12d6106ea4ca1b6aae@syzkaller.appspotmail.com Signed-off-by: Phillip Potter <phil@philpotter.co.uk> Cc: stable@kernel.org Link: https://lore.kernel.org/r/20210412073837.1686-1-phil@philpotter.co.uk Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-09ext4: fix trailing whitespaceJack Qiu
Made suggested modifications from checkpatch in reference to ERROR: trailing whitespace Signed-off-by: Jack Qiu <jack.qiu@huawei.com> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/20210409042035.15516-1-jack.qiu@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-09ext4: add proc files to monitor new structuresHarshad Shirwadkar
This patch adds a new file "mb_structs_summary" which allows us to see the summary of the new allocator structures added in this series. Here's the sample output of file: optimize_scan: 1 max_free_order_lists: list_order_0_groups: 0 list_order_1_groups: 0 list_order_2_groups: 0 list_order_3_groups: 0 list_order_4_groups: 0 list_order_5_groups: 0 list_order_6_groups: 0 list_order_7_groups: 0 list_order_8_groups: 0 list_order_9_groups: 0 list_order_10_groups: 0 list_order_11_groups: 0 list_order_12_groups: 0 list_order_13_groups: 40 fragment_size_tree: tree_min: 16384 tree_max: 32768 tree_nodes: 40 Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20210401172129.189766-7-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-09ext4: improve cr 0 / cr 1 group scanningHarshad Shirwadkar
Instead of traversing through groups linearly, scan groups in specific orders at cr 0 and cr 1. At cr 0, we want to find groups that have the largest free order >= the order of the request. So, with this patch, we maintain lists for each possible order and insert each group into a list based on the largest free order in its buddy bitmap. During cr 0 allocation, we traverse these lists in the increasing order of largest free orders. This allows us to find a group with the best available cr 0 match in constant time. If nothing can be found, we fallback to cr 1 immediately. At CR1, the story is slightly different. We want to traverse in the order of increasing average fragment size. For CR1, we maintain a rb tree of groupinfos which is sorted by average fragment size. Instead of traversing linearly, at CR1, we traverse in the order of increasing average fragment size, starting at the most optimal group. This brings down cr 1 search complexity to log(num groups). For cr >= 2, we just perform the linear search as before. Also, in case of lock contention, we intermittently fallback to linear search even in CR 0 and CR 1 cases. This allows us to proceed during the allocation path even in case of high contention. There is an opportunity to do optimization at CR2 too. That's because at CR2 we only consider groups where bb_free counter (number of free blocks) is greater than the request extent size. That's left as future work. All the changes introduced in this patch are protected under a new mount option "mb_optimize_scan". With this patchset, following experiment was performed: Created a highly fragmented disk of size 65TB. The disk had no contiguous 2M regions. Following command was run consecutively for 3 times: time dd if=/dev/urandom of=file bs=2M count=10 Here are the results with and without cr 0/1 optimizations introduced in this patch: |---------+------------------------------+---------------------------| | | Without CR 0/1 Optimizations | With CR 0/1 Optimizations | |---------+------------------------------+---------------------------| | 1st run | 5m1.871s | 2m47.642s | | 2nd run | 2m28.390s | 0m0.611s | | 3rd run | 2m26.530s | 0m1.255s | |---------+------------------------------+---------------------------| Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/20210401172129.189766-6-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-09ext4: add MB_NUM_ORDERS macroHarshad Shirwadkar
A few arrays in mballoc.c use the total number of valid orders as their size. Currently, this value is set as "sb->s_blocksize_bits + 2". This makes code harder to read. So, instead add a new macro MB_NUM_ORDERS(sb) to make the code more readable. Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20210401172129.189766-5-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-09ext4: add mballoc stats proc fileHarshad Shirwadkar
Add new stats for measuring the performance of mballoc. This patch is forked from Artem Blagodarenko's work that can be found here: https://github.com/lustre/lustre-release/blob/master/ldiskfs/kernel_patches/patches/rhel8/ext4-simple-blockalloc.patch This patch reorganizes the stats by cr level. This is how the output looks like: mballoc: reqs: 0 success: 0 groups_scanned: 0 cr0_stats: hits: 0 groups_considered: 0 useless_loops: 0 bad_suggestions: 0 cr1_stats: hits: 0 groups_considered: 0 useless_loops: 0 bad_suggestions: 0 cr2_stats: hits: 0 groups_considered: 0 useless_loops: 0 cr3_stats: hits: 0 groups_considered: 0 useless_loops: 0 extents_scanned: 0 goal_hits: 0 2^n_hits: 0 breaks: 0 lost: 0 buddies_generated: 0/40 buddies_time_used: 0 preallocated: 0 discarded: 0 Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20210401172129.189766-4-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-09ext4: drop s_mb_bal_lock and convert protected fields to atomicHarshad Shirwadkar
s_mb_buddies_generated gets used later in this patch series to determine if the cr 0 and cr 1 optimziations should be performed or not. Currently, s_mb_buddies_generated is protected under a spin_lock. In the allocation path, it is better if we don't depend on the lock and instead read the value atomically. In order to do that, we drop s_bal_lock altogether and we convert the only two protected fields by it s_mb_buddies_generated and s_mb_generation_time to atomic type. Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com> Link: https://lore.kernel.org/r/20210401172129.189766-2-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-03-06fs/ext4: fix integer overflow in s_log_groups_per_flexSabyrzhan Tasbolatov
syzbot found UBSAN: shift-out-of-bounds in ext4_mb_init [1], when 1 << sbi->s_es->s_log_groups_per_flex is bigger than UINT_MAX, where sbi->s_mb_prefetch is unsigned integer type. 32 is the maximum allowed power of s_log_groups_per_flex. Following if check will also trigger UBSAN shift-out-of-bound: if (1 << sbi->s_es->s_log_groups_per_flex >= UINT_MAX) { So I'm checking it against the raw number, perhaps there is another way to calculate UINT_MAX max power. Also use min_t as to make sure it's uint type. [1] UBSAN: shift-out-of-bounds in fs/ext4/mballoc.c:2713:24 shift exponent 60 is too large for 32-bit type 'int' Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x137/0x1be lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:148 [inline] __ubsan_handle_shift_out_of_bounds+0x432/0x4d0 lib/ubsan.c:395 ext4_mb_init_backend fs/ext4/mballoc.c:2713 [inline] ext4_mb_init+0x19bc/0x19f0 fs/ext4/mballoc.c:2898 ext4_fill_super+0xc2ec/0xfbe0 fs/ext4/super.c:4983 Reported-by: syzbot+a8b4b0c60155e87e9484@syzkaller.appspotmail.com Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210224095800.3350002-1-snovitoll@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-12-22ext4: avoid s_mb_prefetch to be zero in individual scenariosChunguang Xu
Commit cfd732377221 ("ext4: add prefetching for block allocation bitmaps") introduced block bitmap prefetch, and expects to read block bitmaps of flex_bg through an IO. However, it seems to ignore the value range of s_log_groups_per_flex. In the scenario where the value of s_log_groups_per_flex is greater than 27, s_mb_prefetch or s_mb_prefetch_limit will overflow, cause a divide zero exception. In addition, the logic of calculating nr is also flawed, because the size of flexbg is fixed during a single mount, but s_mb_prefetch can be modified, which causes nr to fail to meet the value condition of [1, flexbg_size]. To solve this problem, we need to set the upper limit of s_mb_prefetch. Since we expect to load block bitmaps of a flex_bg through an IO, we can consider determining a reasonable upper limit among the IO limit parameters. After consideration, we chose BLK_MAX_SEGMENT_SIZE. This is a good choice to solve divide zero problem and avoiding performance degradation. [ Some minor code simplifications to make the changes easy to follow -- TYT ] Reported-by: Tosk Robot <tencent_os_robot@tencent.com> Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Samuel Liao <samuelliao@tencent.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/1607051143-24508-1-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-12-17ext4: fix a memory leak of ext4_free_dataChunguang Xu
When freeing metadata, we will create an ext4_free_data and insert it into the pending free list. After the current transaction is committed, the object will be freed. ext4_mb_free_metadata() will check whether the area to be freed overlaps with the pending free list. If true, return directly. At this time, ext4_free_data is leaked. Fortunately, the probability of this problem is small, since it only occurs if the file system is corrupted such that a block is claimed by more one inode and those inodes are deleted within a single jbd2 transaction. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Link: https://lore.kernel.org/r/1604764698-4269-8-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2020-12-03ext4: simplify the code of mb_find_order_for_blockChunguang Xu
The code of mb_find_order_for_block is a bit obscure, but we can simplify it with mb_find_buddy(), make the code more concise. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/1604764698-4269-3-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-12-03ext4: remove redundant mb_regenerate_buddy()Chunguang Xu
After this patch (163a203), if an abnormal bitmap is detected, we will mark the group as corrupt, and we will not use this group in the future. Therefore, it should be meaningless to regenerate the buddy bitmap of this group, It might be better to delete it. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/1604764698-4269-2-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06ext4: make s_mount_flags modifications atomicHarshad Shirwadkar
Fast commit file system states are recorded in sbi->s_mount_flags. Fast commit expects these bit manipulations to be atomic. This patch adds helpers to make those modifications atomic. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201106035911.1942128-21-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-11-06ext4: silence an uninitialized variable warningDan Carpenter
Smatch complains that "i" can be uninitialized if we don't enter the loop. I don't know if it's possible but we may as well silence this warning. [ Initialize i to sb->s_blocksize instead of 0. The only way the for loop could be skipped entirely is the in-memory data structures, in particular the bh->b_data for the on-disk superblock has gotten corrupted enough that calculated value of group is >= to ext4_get_groups_count(sb). In that case, we want to exit immediately without allocating a block. -- TYT ] Fixes: 8016e29f4362 ("ext4: fast commit recovery path") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20201030114620.GB3251003@mwanda Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2020-10-21ext4: fast commit recovery pathHarshad Shirwadkar
This patch adds fast commit recovery path support for Ext4 file system. We add several helper functions that are similar in spirit to e2fsprogs journal recovery path handlers. Example of such functions include - a simple block allocator, idempotent block bitmap update function etc. Using these routines and the fast commit log in the fast commit area, the recovery path (ext4_fc_replay()) performs fast commit log recovery. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201015203802.3597742-8-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: make mb_check_counter per groupChunguang Xu
Make bb_check_counter per group, so each group has the same chance to be checked, which can expose errors more easily. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Link: https://lore.kernel.org/r/1601292995-32205-2-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: delete invalid comments near mb_buddy_adjust_borderChunguang Xu
The comment near mb_buddy_adjust_border seems meaningless, just clear it. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Link: https://lore.kernel.org/r/1601292995-32205-1-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: delete duplicated words + other fixesRandy Dunlap
Delete repeated words in fs/ext4/. {the, this, of, we, after} Also change spelling of "xttr" in inline.c to "xattr" in 2 places. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200805024850.12129-1-rdunlap@infradead.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: discard preallocations before releasing group lockJan Kara
ext4_mb_discard_group_preallocations() can be releasing group lock with preallocations accumulated on its local list. Thus although discard_pa_seq was incremented and concurrent allocating processes will be retrying allocations, it can happen that premature ENOSPC error is returned because blocks used for preallocations are not available for reuse yet. Make sure we always free locally accumulated preallocations before releasing group lock. Fixes: 07b5b8e1ac40 ("ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling") Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200924150959.4335-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: fix dead loop in ext4_mb_new_blocksYe Bin
As we test disk offline/online with running fsstress, we find fsstress process is keeping running state. kworker/u32:3-262 [004] ...1 140.787471: ext4_mb_discard_preallocations: dev 8,32 needed 114 .... kworker/u32:3-262 [004] ...1 140.787471: ext4_mb_discard_preallocations: dev 8,32 needed 114 ext4_mb_new_blocks repeat: ext4_mb_discard_preallocations_should_retry(sb, ac, &seq) freed = ext4_mb_discard_preallocations ext4_mb_discard_group_preallocations this_cpu_inc(discard_pa_seq); ---> freed == 0 seq_retry = ext4_get_discard_pa_seq_sum for_each_possible_cpu(__cpu) __seq += per_cpu(discard_pa_seq, __cpu); if (seq_retry != *seq) { *seq = seq_retry; ret = true; } As we see seq_retry is sum of discard_pa_seq every cpu, if ext4_mb_discard_group_preallocations return zero discard_pa_seq in this cpu maybe increase one, so condition "seq_retry != *seq" have always been met. Ritesh Harjani suggest to in ext4_mb_discard_group_preallocations function we only increase discard_pa_seq when there is some PA to free. Fixes: 07b5b8e1ac40 ("ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling") Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/20200916113859.1556397-3-yebin10@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-19ext4: limit the length of per-inode prealloc listbrookxu
In the scenario of writing sparse files, the per-inode prealloc list may be very long, resulting in high overhead for ext4_mb_use_preallocated(). To circumvent this problem, we limit the maximum length of per-inode prealloc list to 512 and allow users to modify it. After patching, we observed that the sys ratio of cpu has dropped, and the system throughput has increased significantly. We created a process to write the sparse file, and the running time of the process on the fixed kernel was significantly reduced, as follows: Running time on unfixed kernel： [root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat real 0m2.051s user 0m0.008s sys 0m2.026s Running time on fixed kernel： [root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat real 0m0.471s user 0m0.004s sys 0m0.395s Signed-off-by: Chunguang Xu <brookxu@tencent.com> Link: https://lore.kernel.org/r/d7a98178-056b-6db5-6bce-4ead23f4a257@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-19ext4: reorganize if statement of ext4_mb_release_context()brookxu
Reorganize the if statement of ext4_mb_release_context(), make it easier to read. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Link: https://lore.kernel.org/r/5439ac6f-db79-ad68-76c1-a4dda9aa0cc3@gmail.com Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-19ext4: add mb_debug logging when there are lost chunksbrookxu
Lost chunks are when some other process raced with the current thread to grab a particular block allocation. Add mb_debug log for developers who wants to see how often this is happening for a particular workload. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Link: https://lore.kernel.org/r/0a165ac0-1912-aebd-8a0d-b42e7cd1aea1@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-18mballoc: replace seq_printf with seq_putsXu Wang
seq_puts is a lot cheaper than seq_printf, so use that to print literal strings. Signed-off-by: Xu Wang <vulab@iscas.ac.cn> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/20200810022158.9167-1-vulab@iscas.ac.cn Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-18ext4: optimize the implementation of ext4_mb_good_group()brookxu
It might be better to adjust the code in two places: 1. Determine whether grp is currupt or not should be placed first. 2. (cr<=2 && free <ac->ac_g_ex.fe_len)should may belong to the crx strategy, and it may be more appropriate to put it in the subsequent switch statement block. For cr1, cr2, the conditions in switch potentially realize the above judgment. For cr0, we should add (free <ac->ac_g_ex.fe_len) judgment, and then delete (free / fragments) >= ac->ac_g_ex.fe_len), because cr0 returns true by default. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/e20b2d8f-1154-adb7-3831-a9e11ba842e9@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-18ext4: delete invalid comments near ext4_mb_check_limits()brookxu
These comments do not seem to be related to ext4_mb_check_limits(), it may be invalid. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/c49faf0c-d5d5-9c51-6911-9e0ff57c6bfa@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-18ext4: fix typos in ext4_mb_regular_allocator() commentbrookxu
Fix typos in ext4_mb_regular_allocator() comment Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/d6514145-73b3-808b-ec5a-a8be27c51f9c@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-07ext4: check journal inode extents more carefullyJan Kara
Currently, system zones just track ranges of block, that are "important" fs metadata (bitmaps, group descriptors, journal blocks, etc.). This however complicates how extent tree (or indirect blocks) can be checked for inodes that actually track such metadata - currently the journal inode but arguably we should be treating quota files or resize inode similarly. We cannot run __ext4_ext_check() on such metadata inodes when loading their extents as that would immediately trigger the validity checks and so we just hack around that and special-case the journal inode. This however leads to a situation that a journal inode which has extent tree of depth at least one can have invalid extent tree that gets unnoticed until ext4_cache_extents() crashes. To overcome this limitation, track inode number each system zone belongs to (0 is used for zones not belonging to any inode). We can then verify inode number matches the expected one when verifying extent tree and thus avoid the false errors. With this there's no need to to special-case journal inode during extent tree checking anymore so remove it. Fixes: 0a944e8a6c66 ("ext4: don't perform block validity checks on the journal inode") Reported-by: Wolfgang Frisch <wolfgang.frisch@suse.com> Reviewed-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200728130437.7804-4-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-07ext4: delete the invalid BUGON in ext4_mb_load_buddy_gfp()brookxu
Delete the invalid BUGON in ext4_mb_load_buddy_gfp(), the previous code has already judged whether page is NULL. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/ad68e8a2-5ec3-5beb-537f-f3e53f55367a@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-08-07ext4: add prefetch_block_bitmaps mount optionTheodore Ts'o
For file systems where we can afford to keep the buddy bitmaps cached, we can speed up initial writes to large file systems by starting to load the block allocation bitmaps as soon as the file system is mounted. This won't work well for _super_ large file systems, or memory constrained systems, so we only enable this when it is requested via a mount option. Addresses-Google-Bug: 159488342 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Andreas Dilger <adilger@dilger.ca>
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