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Commit Graph

622 Commits

Author SHA1 Message Date
Kemeng Shi
d2f7cf40ea ext4: make state in ext4_mb_mark_bb to be bool
As state could only be either 0 or 1, just make it bool.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-10-05 22:32:15 -04:00
Wang Jianjian
ebf6cb7c6e ext4: no need to generate from free list in mballoc
Commit 7a2fcbf7f8 ("ext4: don't use blocks freed but not yet committed in
buddy cache init") added a code to mark as used blocks in the list of not yet
committed freed blocks during initialization of a buddy page. However
ext4_mb_free_metadata() makes sure buddy page is already loaded and takes a
reference to it so it cannot happen that ext4_mb_init_cache() is called
when efd list is non-empty. Just remove the
ext4_mb_generate_from_freelist() call.

Fixes: 7a2fcbf7f85('ext4: don't use blocks freed but not yet committed in buddy cache init')
Signed-off-by: Wang Jianjian <wangjianjian0@foxmail.com>
Link: https://lore.kernel.org/r/tencent_53CBCB1668358AE862684E453DF37B722008@qq.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
2023-10-05 22:32:14 -04:00
Jinke Han
ce774e5365 ext4: make running and commit transaction have their own freed_data_list
When releasing space in jbd, we traverse s_freed_data_list to get the
free range belonging to the current commit transaction. In extreme cases,
the time spent may not be small, and we have observed cases exceeding
10ms. This patch makes running and commit transactions manage their own
free_data_list respectively, eliminating unnecessary traversal.

And in the callback phase of the commit transaction, no one will touch
it except the jbd thread itself, so s_md_lock is no longer needed.

Signed-off-by: Jinke Han <hanjinke.666@bytedance.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20230612124017.14115-1-hanjinke.666@bytedance.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-10-05 21:48:03 -04:00
Jan Kara
5229a658f6 ext4: do not let fstrim block system suspend
Len Brown has reported that system suspend sometimes fail due to
inability to freeze a task working in ext4_trim_fs() for one minute.
Trimming a large filesystem on a disk that slowly processes discard
requests can indeed take a long time. Since discard is just an advisory
call, it is perfectly fine to interrupt it at any time and the return
number of discarded blocks until that moment. Do that when we detect the
task is being frozen.

Cc: stable@kernel.org
Reported-by: Len Brown <lenb@kernel.org>
Suggested-by: Dave Chinner <david@fromorbit.com>
References: https://bugzilla.kernel.org/show_bug.cgi?id=216322
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230913150504.9054-2-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-09-14 12:06:59 -04:00
Jan Kara
45e4ab320c ext4: move setting of trimmed bit into ext4_try_to_trim_range()
Currently we set the group's trimmed bit in ext4_trim_all_free() based
on return value of ext4_try_to_trim_range(). However when we will want
to abort trimming because of suspend attempt, we want to return success
from ext4_try_to_trim_range() but not set the trimmed bit. Instead
implementing awkward propagation of this information, just move setting
of trimmed bit into ext4_try_to_trim_range() when the whole group is
trimmed.

Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230913150504.9054-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-09-14 12:06:47 -04:00
Ruan Jinjie
0f6bc57971 ext4: use LIST_HEAD() to initialize the list_head in mballoc.c
Use LIST_HEAD() to initialize the list_head instead of open-coding it.

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/r/20230812071839.3481909-1-ruanjinjie@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-27 11:27:13 -04:00
Su Hui
a50bda1474 ext4: mballoc: avoid garbage value from err
clang's static analysis warning: fs/ext4/mballoc.c
line 4178, column 6, Branch condition evaluates to a garbage value.

err is uninitialized and will be judged when 'len <= 0' or
it first enters the loop while the condition "!ext4_sb_block_valid()"
is true. Although this can't make problems now, it's better to
correct it.

Signed-off-by: Su Hui <suhui@nfschina.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20230725043310.1227621-1-suhui@nfschina.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-27 11:27:12 -04:00
Lu Hongfei
79ebf48c44 ext4: use sbi instead of EXT4_SB(sb) in ext4_mb_new_blocks_simple()
Signed-off-by: Lu Hongfei <luhongfei@vivo.com>
Link: https://lore.kernel.org/r/20230707115907.26637-1-luhongfei@vivo.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-27 11:27:12 -04:00
Lu Hongfei
89cadf6e22 ext4: change the type of blocksize in ext4_mb_init_cache()
The return value type of i_blocksize() is 'unsigned int', so the
type of blocksize has been modified from 'int' to 'unsigned int'
to ensure data type consistency.

Signed-off-by: Lu Hongfei <luhongfei@vivo.com>
Link: https://lore.kernel.org/r/20230707105516.9156-1-luhongfei@vivo.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-27 11:27:12 -04:00
Ritesh Harjani
772c9f691d ext4: don't use CR_BEST_AVAIL_LEN for non-regular files
Using CR_BEST_AVAIL_LEN only make sense for regular files, as for
non-regular files we never normalize the allocation request length i.e.
goal len is same as original length (ac_g_ex.fe_len == ac_o_ex.fe_len).

Hence there is no scope of trimming the goal length to make it
satisfy original request len. Thus this patch avoids using
CR_BEST_AVAIL_LEN criteria for non-regular files request.

Cc: stable@kernel.org
Fixes: 33122aa930f1 ("ext4: Add allocation criteria 1.5 (CR1_5)")
Reported-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Tested-by: Eric Whitney <enwlinux@gmail.com>
Link: https://lore.kernel.org/r/2a694c748ff8b8c4b416995a24f06f07b55047a8.1689516047.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-05 08:18:04 -04:00
Kemeng Shi
4eea9fbed9 ext4: correct some stale comment of criteria
We named criteria with CR_XXX, correct stale comment to criteria with
raw number.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-11-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:47:30 -04:00
Kemeng Shi
bcb123ac9b ext4: return found group directly in ext4_mb_choose_next_group_best_avail
Return good group when it's found in loop to remove futher check if good
group is found after loop.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-10-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:47:30 -04:00
Kemeng Shi
b50675a4a6 ext4: return found group directly in ext4_mb_choose_next_group_goal_fast
Return good group when it's found in loop to remove futher check if good
group is found after loop.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-9-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:47:30 -04:00
Kemeng Shi
de8bf0e5ee ext4: replace the traditional ternary conditional operator with with max()/min()
Replace the traditional ternary conditional operator with with max()/min()

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-7-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:47:30 -04:00
Kemeng Shi
ad635507b5 ext4: remove unnecessary return for void function
The return at end of void function is unnecessary, just remove it.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-6-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:47:30 -04:00
Kemeng Shi
bb60caa2db ext4: use is_power_of_2 helper in ext4_mb_regular_allocator
Use intuitive is_power_of_2 helper in ext4_mb_regular_allocator.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-5-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:47:30 -04:00
Kemeng Shi
919eb90cec ext4: return found group directly in ext4_mb_choose_next_group_p2_aligned
Return good group when it's found in loop to remove unnecessary NULL
initialization of grp and futher check if good group is found after loop.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-4-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:47:30 -04:00
Kemeng Shi
60c672b7f2 ext4: avoid potential data overflow in next_linear_group
ngroups is ext4_group_t (unsigned int) while next_linear_group treat it
in int. If ngroups is bigger than max number described by int, it will
be treat as a negative number. Then "return group + 1 >= ngroups ? 0 :
group + 1;" may keep returning 0.
Switch int to ext4_group_t in next_linear_group to fix the overflow.

Fixes: 196e402adf ("ext4: improve cr 0 / cr 1 group scanning")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:47:29 -04:00
Kemeng Shi
a9ce5993a0 ext4: correct grp validation in ext4_mb_good_group
Group corruption check will access memory of grp and will trigger kernel
crash if grp is NULL. So do NULL check before corruption check.

Fixes: 5354b2af34 ("ext4: allow ext4_get_group_info() to fail")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230801143204.2284343-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:47:29 -04:00
Ojaswin Mujoo
304749c0d5 ext4: replace CR_FAST macro with inline function for readability
Replace CR_FAST with ext4_mb_cr_expensive() inline function for better
readability. This function returns true if the criteria is one of the
expensive/slower ones where lots of disk IO/prefetching is acceptable.

No functional changes are intended in this patch.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230630085927.140137-1-ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-08-03 10:39:05 -04:00
Jan Kara
95257987a6 ext4: drop EXT4_MF_FS_ABORTED flag
EXT4_MF_FS_ABORTED flag has practically the same intent as
EXT4_FLAGS_SHUTDOWN flag. The shutdown flag is checked in many more
places than the aborted flag which is mostly the historical artifact
where we were relying on SB_RDONLY checks instead of the aborted flag
checks. There are only three places - ext4_sync_file(),
__ext4_remount(), and mballoc debug code - which check aborted flag and
not shutdown flag and this is arguably a bug. Avoid these
inconsistencies by removing EXT4_MF_FS_ABORTED flag and using
EXT4_FLAGS_SHUTDOWN everywhere.

Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230616165109.21695-5-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-07-29 18:37:53 -04:00
Baokun Li
bedc5d3463 ext4: avoid overlapping preallocations due to overflow
Let's say we want to allocate 2 blocks starting from 4294966386, after
predicting the file size, start is aligned to 4294965248, len is changed
to 2048, then end = start + size = 0x100000000. Since end is of
type ext4_lblk_t, i.e. uint, end is truncated to 0.

This causes (pa->pa_lstart >= end) to always hold when checking if the
current extent to be allocated crosses already preallocated blocks, so the
resulting ac_g_ex may cross already preallocated blocks. Hence we convert
the end type to loff_t and use pa_logical_end() to avoid overflow.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230724121059.11834-4-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-07-29 00:02:30 -04:00
Baokun Li
bc056e7163 ext4: fix BUG in ext4_mb_new_inode_pa() due to overflow
When we calculate the end position of ext4_free_extent, this position may
be exactly where ext4_lblk_t (i.e. uint) overflows. For example, if
ac_g_ex.fe_logical is 4294965248 and ac_orig_goal_len is 2048, then the
computed end is 0x100000000, which is 0. If ac->ac_o_ex.fe_logical is not
the first case of adjusting the best extent, that is, new_bex_end > 0, the
following BUG_ON will be triggered:

=========================================================
kernel BUG at fs/ext4/mballoc.c:5116!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 3 PID: 673 Comm: xfs_io Tainted: G E 6.5.0-rc1+ #279
RIP: 0010:ext4_mb_new_inode_pa+0xc5/0x430
Call Trace:
 <TASK>
 ext4_mb_use_best_found+0x203/0x2f0
 ext4_mb_try_best_found+0x163/0x240
 ext4_mb_regular_allocator+0x158/0x1550
 ext4_mb_new_blocks+0x86a/0xe10
 ext4_ext_map_blocks+0xb0c/0x13a0
 ext4_map_blocks+0x2cd/0x8f0
 ext4_iomap_begin+0x27b/0x400
 iomap_iter+0x222/0x3d0
 __iomap_dio_rw+0x243/0xcb0
 iomap_dio_rw+0x16/0x80
=========================================================

A simple reproducer demonstrating the problem:

	mkfs.ext4 -F /dev/sda -b 4096 100M
	mount /dev/sda /tmp/test
	fallocate -l1M /tmp/test/tmp
	fallocate -l10M /tmp/test/file
	fallocate -i -o 1M -l16777203M /tmp/test/file
	fsstress -d /tmp/test -l 0 -n 100000 -p 8 &
	sleep 10 && killall -9 fsstress
	rm -f /tmp/test/tmp
	xfs_io -c "open -ad /tmp/test/file" -c "pwrite -S 0xff 0 8192"

We simply refactor the logic for adjusting the best extent by adding
a temporary ext4_free_extent ex and use extent_logical_end() to avoid
overflow, which also simplifies the code.

Cc: stable@kernel.org # 6.4
Fixes: 93cdf49f6e ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230724121059.11834-3-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-07-29 00:02:30 -04:00
Baokun Li
43bbddc067 ext4: add two helper functions extent_logical_end() and pa_logical_end()
When we use lstart + len to calculate the end of free extent or prealloc
space, it may exceed the maximum value of 4294967295(0xffffffff) supported
by ext4_lblk_t and cause overflow, which may lead to various problems.

Therefore, we add two helper functions, extent_logical_end() and
pa_logical_end(), to limit the type of end to loff_t, and also convert
lstart to loff_t for calculation to avoid overflow.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230724121059.11834-2-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-07-29 00:02:30 -04:00
Ojaswin Mujoo
9d3de7ee19 ext4: fix rbtree traversal bug in ext4_mb_use_preallocated
During allocations, while looking for preallocations(PA) in the per
inode rbtree, we can't do a direct traversal of the tree because
ext4_mb_discard_group_preallocation() can paralelly mark the pa deleted
and that can cause direct traversal to skip some entries. This was
leading to a BUG_ON() being hit [1] when we missed a PA that could satisfy
our request and ultimately tried to create a new PA that would overlap
with the missed one.

To makes sure we handle that case while still keeping the performance of
the rbtree, we make use of the fact that the only pa that could possibly
overlap the original goal start is the one that satisfies the below
conditions:

  1. It must have it's logical start immediately to the left of
  (ie less than) original logical start.

  2. It must not be deleted

To find this pa we use the following traversal method:

1. Descend into the rbtree normally to find the immediate neighboring
PA. Here we keep descending irrespective of if the PA is deleted or if
it overlaps with our request etc. The goal is to find an immediately
adjacent PA.

2. If the found PA is on right of original goal, use rb_prev() to find
the left adjacent PA.

3. Check if this PA is deleted and keep moving left with rb_prev() until
a non deleted PA is found.

4. This is the PA we are looking for. Now we can check if it can satisfy
the original request and proceed accordingly.

This approach also takes care of having deleted PAs in the tree.

(While we are at it, also fix a possible overflow bug in calculating the
end of a PA)

[1] https://lore.kernel.org/linux-ext4/CA+G9fYv2FRpLqBZf34ZinR8bU2_ZRAUOjKAD3+tKRFaEQHtt8Q@mail.gmail.com/

Cc: stable@kernel.org # 6.4
Fixes: 3872778664 ("ext4: Use rbtrees to manage PAs instead of inode i_prealloc_list")
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reviewed-by: Ritesh Harjani (IBM) ritesh.list@gmail.com
Tested-by: Ritesh Harjani (IBM) ritesh.list@gmail.com
Link: https://lore.kernel.org/r/edd2efda6a83e6343c5ace9deea44813e71dbe20.1690045963.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-07-23 08:21:14 -04:00
Ojaswin Mujoo
5d5460fa79 ext4: fix off by one issue in ext4_mb_choose_next_group_best_avail()
In ext4_mb_choose_next_group_best_avail(), we want the start order to be
1 less than goal length and the min_order to be, at max, 1 more than the
original length. This commit fixes an off by one issue that arose due to
the fact that 1 << fls(n) > (n).

After all the processing:

order = 1 order below goal len
min_order = maximum of the three:-
             - order - trim_order
             - 1 order below B2C(s_stripe)
             - 1 order above original len

Cc: stable@kernel.org
Fixes: 33122aa930 ("ext4: Add allocation criteria 1.5 (CR1_5)")
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230609103403.112807-1-ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-07-23 08:21:14 -04:00
Theodore Ts'o
4c0cfebdf3 ext4: clean up mballoc criteria comments
Line wrap and slightly clarify the comments describing mballoc's
cirtiera.

Define EXT4_MB_NUM_CRS as part of the enum, so that it will
automatically get updated when criteria is added or removed.

Also fix a potential unitialized use of 'cr' variable if
CONFIG_EXT4_DEBUG is enabled.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:35:12 -04:00
Ojaswin Mujoo
f52f3d2b9f ext4: Give symbolic names to mballoc criterias
mballoc criterias have historically been called by numbers
like CR0, CR1... however this makes it confusing to understand
what each criteria is about.

Change these criterias from numbers to symbolic names and add
relevant comments. While we are at it, also reformat and add some
comments to ext4_seq_mb_stats_show() for better readability.

Additionally, define CR_FAST which signifies the criteria
below which we can make quicker decisions like:
  * quitting early if (free block < requested len)
  * avoiding to scan free extents smaller than required len.
  * avoiding to initialize buddy cache and work with existing cache
  * limiting prefetches

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/a2dc6ec5aea5e5e68cf8e788c2a964ffead9c8b0.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Ojaswin Mujoo
7e170922f0 ext4: Add allocation criteria 1.5 (CR1_5)
CR1_5 aims to optimize allocations which can't be satisfied in CR1. The
fact that we couldn't find a group in CR1 suggests that it would be
difficult to find a continuous extent to compleltely satisfy our
allocations. So before falling to the slower CR2, in CR1.5 we
proactively trim the the preallocations so we can find a group with
(free / fragments) big enough.  This speeds up our allocation at the
cost of slightly reduced preallocation.

The patch also adds a new sysfs tunable:

* /sys/fs/ext4/<partition>/mb_cr1_5_max_trim_order

This controls how much CR1.5 can trim a request before falling to CR2.
For example, for a request of order 7 and max trim order 2, CR1.5 can
trim this upto order 5.

Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/150fdf65c8e4cc4dba71e020ce0859bcf636a5ff.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Ojaswin Mujoo
856d865c17 ext4: Abstract out logic to search average fragment list
Make the logic of searching average fragment list of a given order reusable
by abstracting it out to a differnet function. This will also avoid
code duplication in upcoming patches.

No functional changes.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/028c11d95b17ce0285f45456709a0ca922df1b83.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Ojaswin Mujoo
4f3d1e4533 ext4: Ensure ext4_mb_prefetch_fini() is called for all prefetched BGs
Before this patch, the call stack in ext4_run_li_request is as follows:

  /*
   * nr = no. of BGs we want to fetch (=s_mb_prefetch)
   * prefetch_ios = no. of BGs not uptodate after
   * 		    ext4_read_block_bitmap_nowait()
   */
  next_group = ext4_mb_prefetch(sb, group, nr, prefetch_ios);
  ext4_mb_prefetch_fini(sb, next_group prefetch_ios);

ext4_mb_prefetch_fini() will only try to initialize buddies for BGs in
range [next_group - prefetch_ios, next_group). This is incorrect since
sometimes (prefetch_ios < nr), which causes ext4_mb_prefetch_fini() to
incorrectly ignore some of the BGs that might need initialization. This
issue is more notable now with the previous patch enabling "fetching" of
BLOCK_UNINIT BGs which are marked buffer_uptodate by default.

Fix this by passing nr to ext4_mb_prefetch_fini() instead of
prefetch_ios so that it considers the right range of groups.

Similarly, make sure we don't pass nr=0 to ext4_mb_prefetch_fini() in
ext4_mb_regular_allocator() since we might have prefetched BLOCK_UNINIT
groups that would need buddy initialization.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/05e648ae04ec5b754207032823e9c1de9a54f87a.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Ojaswin Mujoo
3c6296046c ext4: Don't skip prefetching BLOCK_UNINIT groups
Currently, ext4_mb_prefetch() and ext4_mb_prefetch_fini() skip
BLOCK_UNINIT groups since fetching their bitmaps doesn't need disk IO.
As a consequence, we end not initializing the buddy structures and CR0/1
lists for these BGs, even though it can be done without any disk IO
overhead. Hence, don't skip such BGs during prefetch and prefetch_fini.

This improves the accuracy of CR0/1 allocation as earlier, we could have
essentially empty BLOCK_UNINIT groups being ignored by CR0/1 due to their buddy
not being initialized, leading to slower CR2 allocations. With this patch CR0/1
will be able to discover these groups as well, thus improving performance.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/dc3130b8daf45ffe63d8a3c1edcf00eb8ba70e1f.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Ojaswin Mujoo
1b42001121 ext4: Avoid scanning smaller extents in BG during CR1
When we are inside ext4_mb_complex_scan_group() in CR1, we can be sure
that this group has atleast 1 big enough continuous free extent to satisfy
our request because (free / fragments) > goal length.

Hence, instead of wasting time looping over smaller free extents, only
try to consider the free extent if we are sure that it has enough
continuous free space to satisfy goal length. This is particularly
useful when scanning highly fragmented BGs in CR1 as, without this
patch, the allocator might stop scanning early before reaching the big
enough free extent (due to ac_found > mb_max_to_scan) which causes us to
uncessarily trim the request.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/a5473df4517c53ec940bc9b603ef83a547032a32.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Ojaswin Mujoo
3ef5d26387 ext4: Add counter to track successful allocation of goal length
Track number of allocations where the length of blocks allocated is equal to the
length of goal blocks (post normalization). This metric could be useful if
making changes to the allocator logic in the future as it could give us
visibility into how often do we trim our requests.

PS: ac_b_ex.fe_len might get modified due to preallocation efforts and
hence we use ac_f_ex.fe_len instead since we want to compare how much the
allocator was able to actually find.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/343620e2be8a237239ea2613a7a866ee8607e973.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Ojaswin Mujoo
fdd9a00943 ext4: Add per CR extent scanned counter
This gives better visibility into the number of extents scanned in each
particular CR. For example, this information can be used to see how out
block group scanning logic is performing when the BG is fragmented.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/55bb6d80f6e22ed2a5a830aa045572bdffc8b1b9.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Ojaswin Mujoo
4eb7a4a1a3 ext4: Convert mballoc cr (criteria) to enum
Convert criteria to be an enum so it easier to maintain and
update the tracefiles to use enum names. This change also makes
it easier to insert new criterias in the future.

There is no functional change in this patch.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/5d82fd467bdf70ea45bdaef810af3b146013946c.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Ritesh Harjani
569f196f1e ext4: mballoc: Remove useless setting of ac_criteria
There will be changes coming in future patches which will introduce a new
criteria for block allocation. This removes the useless setting of ac_criteria.
AFAIU, this might be only used to differentiate between whether a preallocated
blocks was allocated or was regular allocator called for allocating blocks.
Hence this also adds the debug prints to identify what type of block allocation
was done in ext4_mb_show_ac().

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1dbae05617519cb6202f1b299c9d1be3e7cda763.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:56 -04:00
Kemeng Shi
2ec6d0a5ea ext4: fix wrong unit use in ext4_mb_new_blocks
Function ext4_free_blocks_simple needs count in cluster. Function
ext4_free_blocks accepts count in block. Convert count to cluster
to fix the mismatch.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: stable@kernel.org
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-12-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:48 -04:00
Kemeng Shi
247c3d214c ext4: fix wrong unit use in ext4_mb_clear_bb
Function ext4_issue_discard need count in cluster. Pass count_clusters
instead of count to fix the mismatch.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: stable@kernel.org
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-11-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:34:36 -04:00
Kemeng Shi
ad78b5efe4 ext4: remove unused parameter from ext4_mb_new_blocks_simple()
Two cleanups for ext4_mb_new_blocks_simple:
Remove unused parameter handle of ext4_mb_new_blocks_simple.
Move ext4_mb_new_blocks_simple definition before ext4_mb_new_blocks to
remove unnecessary forward declaration of ext4_mb_new_blocks_simple.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-10-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 19:33:59 -04:00
Kemeng Shi
11b6890be0 ext4: get block from bh in ext4_free_blocks for fast commit replay
ext4_free_blocks will retrieve block from bh if block parameter is zero.
Retrieve block before ext4_free_blocks_simple to avoid potentially
passing wrong block to ext4_free_blocks_simple.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: stable@kernel.org
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-9-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-26 18:13:05 -04:00
Kemeng Shi
19a043bb1f ext4: try all groups in ext4_mb_new_blocks_simple
ext4_mb_new_blocks_simple ignores the group before goal, so it will fail
if free blocks reside in group before goal. Try all groups to avoid
unexpected failure.
Search finishes either if any free block is found or if no available
blocks are found. Simpliy check "i >= max" to distinguish the above
cases.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Suggested-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-8-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-15 00:02:10 -04:00
Kemeng Shi
1eff590489 ext4: add EXT4_MB_HINT_GOAL_ONLY test in ext4_mb_use_preallocated
ext4_mb_use_preallocated will ignore the demand to alloc goal blocks,
although the EXT4_MB_HINT_GOAL_ONLY is requested.
For group pa, ext4_mb_group_or_file will not set EXT4_MB_HINT_GROUP_ALLOC
if EXT4_MB_HINT_GOAL_ONLY is set. So we will not alloc goal blocks from
group pa if EXT4_MB_HINT_GOAL_ONLY is set.
For inode pa, ext4_mb_pa_goal_check is added to check if free extent in
found inode pa meets goal blocks when EXT4_MB_HINT_GOAL_ONLY is set.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Suggested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-6-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-15 00:02:10 -04:00
Kemeng Shi
c3defd99d5 ext4: treat stripe in block unit
Stripe is misused in block unit and in cluster unit in different code
paths. User awared of stripe maybe not awared of bigalloc feature, so
treat stripe only in block unit to fix this.
Besides, it's hard to get stripe aligned blocks (start and length are both
aligned with stripe) if stripe is not aligned with cluster, just disable
stripe and alert user in this case to simpfy the code and avoid
unnecessary work to get stripe aligned blocks which likely to be failed.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-5-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-15 00:02:10 -04:00
Kemeng Shi
99c515e3a8 ext4: fix wrong unit use in ext4_mb_find_by_goal
We need start in block unit while fe_start is in cluster unit. Use
ext4_grp_offs_to_block helper to convert fe_start to get start in
block unit.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-4-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-15 00:02:10 -04:00
Kemeng Shi
497885f72d ext4: fix unit mismatch in ext4_mb_new_blocks_simple
The "i" returned from mb_find_next_zero_bit is in cluster unit and we
need offset "block" corresponding to "i" in block unit. Convert "i" to
block unit to fix the unit mismatch.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-15 00:02:10 -04:00
Kemeng Shi
b3916da0d9 ext4: fix wrong unit use in ext4_mb_normalize_request
NRL_CHECK_SIZE will compare input req and size, so req and size should
be in same unit. Input req "fe_len" is in cluster unit while input
size "(8<<20)>>bsbits" is in block unit. Convert "fe_len" to block
unit to fix the mismatch.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230603150327.3596033-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-15 00:02:10 -04:00
Ojaswin Mujoo
3582e74599 Revert "ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ext4_mb_check_limits"
This reverts commit 32c0869370.

The reverted commit was intended to remove a dead check however it was observed
that this check was actually being used to exit early instead of looping
sbi->s_mb_max_to_scan times when we are able to find a free extent bigger than
the goal extent. Due to this, a my performance tests (fsmark, parallel file
writes in a highly fragmented FS) were seeing a 2x-3x regression.

Example, the default value of the following variables is:

sbi->s_mb_max_to_scan = 200
sbi->s_mb_min_to_scan = 10

In ext4_mb_check_limits() if we find an extent smaller than goal, then we return
early and try again. This loop will go on until we have processed
sbi->s_mb_max_to_scan(=200) number of free extents at which point we exit and
just use whatever we have even if it is smaller than goal extent.

Now, the regression comes when we find an extent bigger than goal. Earlier, in
this case we would loop only sbi->s_mb_min_to_scan(=10) times and then just use
the bigger extent. However with commit 32c08693 that check was removed and hence
we would loop sbi->s_mb_max_to_scan(=200) times even though we have a big enough
free extent to satisfy the request. The only time we would exit early would be
when the free extent is *exactly* the size of our goal, which is pretty uncommon
occurrence and so we would almost always end up looping 200 times.

Hence, revert the commit by adding the check back to fix the regression. Also
add a comment to outline this policy.

Fixes: 32c0869370 ("ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ext4_mb_check_limits")
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/ddcae9658e46880dfec2fb0aa61d01fb3353d202.1685449706.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-06-02 14:47:29 -04:00
Theodore Ts'o
463808f237 ext4: remove a BUG_ON in ext4_mb_release_group_pa()
If a malicious fuzzer overwrites the ext4 superblock while it is
mounted such that the s_first_data_block is set to a very large
number, the calculation of the block group can underflow, and trigger
a BUG_ON check.  Change this to be an ext4_warning so that we don't
crash the kernel.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230430154311.579720-3-tytso@mit.edu
Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-05-13 18:05:04 -04:00
Theodore Ts'o
5354b2af34 ext4: allow ext4_get_group_info() to fail
Previously, ext4_get_group_info() would treat an invalid group number
as BUG(), since in theory it should never happen.  However, if a
malicious attaker (or fuzzer) modifies the superblock via the block
device while it is the file system is mounted, it is possible for
s_first_data_block to get set to a very large number.  In that case,
when calculating the block group of some block number (such as the
starting block of a preallocation region), could result in an
underflow and very large block group number.  Then the BUG_ON check in
ext4_get_group_info() would fire, resutling in a denial of service
attack that can be triggered by root or someone with write access to
the block device.

For a quality of implementation perspective, it's best that even if
the system administrator does something that they shouldn't, that it
will not trigger a BUG.  So instead of BUG'ing, ext4_get_group_info()
will call ext4_error and return NULL.  We also add fallback code in
all of the callers of ext4_get_group_info() that it might NULL.

Also, since ext4_get_group_info() was already borderline to be an
inline function, un-inline it.  The results in a next reduction of the
compiled text size of ext4 by roughly 2k.

Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20230430154311.579720-2-tytso@mit.edu
Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2023-05-13 18:02:46 -04:00
Ojaswin Mujoo
361eb69fc9 ext4: Remove the logic to trim inode PAs
Earlier, inode PAs were stored in a linked list. This caused a need to
periodically trim the list down inorder to avoid growing it to a very
large size, as this would severly affect performance during list
iteration.

Recent patches changed this list to an rbtree, and since the tree scales
up much better, we no longer need to have the trim functionality, hence
remove it.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/c409addceaa3ade4b40328e28e3b54b2f259689e.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:13 -04:00
Ojaswin Mujoo
3872778664 ext4: Use rbtrees to manage PAs instead of inode i_prealloc_list
Currently, the kernel uses i_prealloc_list to hold all the inode
preallocations. This is known to cause degradation in performance in
workloads which perform large number of sparse writes on a single file.
This is mainly because functions like ext4_mb_normalize_request() and
ext4_mb_use_preallocated() iterate over this complete list, resulting in
slowdowns when large number of PAs are present.

Patch 27bc446e2 partially fixed this by enforcing a limit of 512 for
the inode preallocation list and adding logic to continually trim the
list if it grows above the threshold, however our testing revealed that
a hardcoded value is not suitable for all kinds of workloads.

To optimize this, add an rbtree to the inode and hold the inode
preallocations in this rbtree. This will make iterating over inode PAs
faster and scale much better than a linked list. Additionally, we also
had to remove the LRU logic that was added during trimming of the list
(in ext4_mb_release_context()) as it will add extra overhead in rbtree.
The discards now happen in the lowest-logical-offset-first order.

** Locking notes **

With the introduction of rbtree to maintain inode PAs, we can't use RCU
to walk the tree for searching since it can result in partial traversals
which might miss some nodes(or entire subtrees) while discards happen
in parallel (which happens under a lock).  Hence this patch converts the
ei->i_prealloc_lock spin_lock to rw_lock.

Almost all the codepaths that read/modify the PA rbtrees are protected
by the higher level inode->i_data_sem (except
ext4_mb_discard_group_preallocations() and ext4_clear_inode()) IIUC, the
only place we need lock protection is when one thread is reading
"searching" the PA rbtree (earlier protected under rcu_read_lock()) and
another is "deleting" the PAs in ext4_mb_discard_group_preallocations()
function (which iterates all the PAs using the grp->bb_prealloc_list and
deletes PAs from the tree without taking any inode lock (i_data_sem)).

So, this patch converts all rcu_read_lock/unlock() paths for inode list
PA to use read_lock() and all places where we were using
ei->i_prealloc_lock spinlock will now be using write_lock().

Note that this makes the fast path (searching of the right PA e.g.
ext4_mb_use_preallocated() or ext4_mb_normalize_request()), now use
read_lock() instead of rcu_read_lock/unlock().  Ths also will now block
due to slow discard path (ext4_mb_discard_group_preallocations()) which
uses write_lock().

But this is not as bad as it looks. This is because -

1. The slow path only occurs when the normal allocation failed and we
   can say that we are low on disk space.  One can argue this scenario
   won't be much frequent.

2. ext4_mb_discard_group_preallocations(), locks and unlocks the rwlock
   for deleting every individual PA.  This gives enough opportunity for
   the fast path to acquire the read_lock for searching the PA inode
   list.

Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/4137bce8f6948fedd8bae134dabae24acfe699c6.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:13 -04:00
Ojaswin Mujoo
a8e38fd37c ext4: Convert pa->pa_inode_list and pa->pa_obj_lock into a union
** Splitting pa->pa_inode_list **

Currently, we use the same pa->pa_inode_list to add a pa to either
the inode preallocation list or the locality group preallocation list.
For better clarity, split this list into a union of 2 list_heads and use
either of the them based on the type of pa.

** Splitting pa->pa_obj_lock **

Currently, pa->pa_obj_lock is either assigned &ei->i_prealloc_lock for
inode PAs or lg_prealloc_lock for lg PAs, and is then used to lock the
lists containing these PAs. Make the distinction between the 2 PA types
clear by changing this lock to a union of 2 locks. Explicitly use the
pa_lock_node.inode_lock for inode PAs and pa_lock_node.lg_lock for lg
PAs.

This patch is required so that the locality group preallocation code
remains the same as in upcoming patches we are going to make changes to
inode preallocation code to move from list to rbtree based
implementation. This patch also makes it easier to review the upcoming
patches.

There are no functional changes in this patch.

Suggested-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1d7ac0557e998c3fc7eef422b52e4bc67bdef2b0.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:13 -04:00
Ojaswin Mujoo
93cdf49f6e ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()
When the length of best extent found is less than the length of goal extent
we need to make sure that the best extent atleast covers the start of the
original request. This is done by adjusting the ac_b_ex.fe_logical (logical
start) of the extent.

While doing so, the current logic sometimes results in the best extent's
logical range overflowing the goal extent. Since this best extent is later
added to the inode preallocation list, we have a possibility of introducing
overlapping preallocations. This is discussed in detail here [1].

As per Jan's suggestion, to fix this, replace the existing logic with the
below logic for adjusting best extent as it keeps fragmentation in check
while ensuring logical range of best extent doesn't overflow out of goal
extent:

1. Check if best extent can be kept at end of goal range and still cover
   original start.
2. Else, check if best extent can be kept at start of goal range and still
   cover original start.
3. Else, keep the best extent at start of original request.

Also, add a few extra BUG_ONs that might help catch errors faster.

[1] https://lore.kernel.org/r/Y+OGkVvzPN0RMv0O@li-bb2b2a4c-3307-11b2-a85c-8fa5c3a69313.ibm.com

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/f96aca6d415b36d1f90db86c1a8cd7e2e9d7ab0e.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:13 -04:00
Ojaswin Mujoo
0830344c95 ext4: Abstract out overlap fix/check logic in ext4_mb_normalize_request()
Abstract out the logic of fixing PA overlaps in ext4_mb_normalize_request
to improve readability of code. This also makes it easier to make changes
to the overlap logic in future.

There are no functional changes in this patch

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/9b35f3955a1d7b66bbd713eca1e63026e01f78c1.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Ojaswin Mujoo
7692094ac5 ext4: Move overlap assert logic into a separate function
Abstract out the logic to double check for overlaps in normalize_pa to
a separate function. Since there has been no reports in past where we
have seen any overlaps which hits this bug_on(), in future we can
consider calling this function under "#ifdef AGGRESSIVE_CHECK" only.

There are no functional changes in this patch

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/35dd5d94fa0b2d1cd2d2947adf8967279c72967d.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Ojaswin Mujoo
bcf4349921 ext4: Refactor code in ext4_mb_normalize_request() and ext4_mb_use_preallocated()
Change some variable names to be more consistent and
refactor some of the code to make it easier to read.

There are no functional changes in this patch

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/8edcab489c06cf861b19d87207d9b0ff7ac7f3c1.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Ojaswin Mujoo
820897258a ext4: Refactor code related to freeing PAs
This patch makes the following changes:

*  Rename ext4_mb_pa_free to ext4_mb_pa_put_free
   to better reflect its purpose

*  Add new ext4_mb_pa_free() which only handles freeing

*  Refactor ext4_mb_pa_callback() to use ext4_mb_pa_free()

There are no functional changes in this patch

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/b273bc9cbf5bd278f641fa5bc6c0cc9e6cb3330c.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Ojaswin Mujoo
e86a718228 ext4: Stop searching if PA doesn't satisfy non-extent file
If we come across a PA that matches the logical offset but is unable to
satisfy a non-extent file due to its physical start being higher than
that supported by non extent files, then simply stop searching for
another PA and break out of loop. This is because, since PAs don't
overlap, we won't be able to find another inode PA which can satisfy the
original request.

Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/42404ca29bd304ae2c962184c3c32a02e8eefcd0.1679731817.git.ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Theodore Ts'o
19b8b035a7 ext4: convert some BUG_ON's in mballoc to use WARN_RATELIMITED instead
In cases where we have an obvious way of continuing, let's use
WARN_RATELIMITED() instead of BUG_ON().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Kemeng Shi
91a48aaf59 ext4: avoid unnecessary pointer dereference in ext4_mb_normalize_request
Result of EXT4_SB(ac->ac_sb) is already stored in sbi at beginning of
ext4_mb_normalize_request. Use sbi instead of EXT4_SB(ac->ac_sb) to
remove unnecessary pointer dereference.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230311170949.1047958-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Kemeng Shi
1221b23501 ext4: fix typos in mballoc
pa_plen -> pa_len
pa_start -> pa_pstart

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230311170949.1047958-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Kemeng Shi
253cacb0de ext4: simplify calculation of blkoff in ext4_mb_new_blocks_simple
We try to allocate a block from goal in ext4_mb_new_blocks_simple. We
only need get blkoff in first group with goal and set blkoff to 0 for
the rest groups.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-21-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Kemeng Shi
46825e9490 ext4: remove comment code ext4_discard_preallocations
Just remove comment code in ext4_discard_preallocations.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-20-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Kemeng Shi
3a037b1b88 ext4: remove repeat assignment to ac_f_ex
Call trace to assign ac_f_ex:
ext4_mb_use_best_found
	ac->ac_f_ex = ac->ac_b_ex;
	ext4_mb_new_preallocation
		ext4_mb_new_group_pa
			ac->ac_f_ex = ac->ac_b_ex;
		ext4_mb_new_inode_pa
			ac->ac_f_ex = ac->ac_b_ex;

Actually allocated blocks is already stored in ac_f_ex in
ext4_mb_use_best_found, so there is no need to assign ac_f_ex
in ext4_mb_new_group_pa and ext4_mb_new_inode_pa.
Just remove repeat assignment to ac_f_ex in ext4_mb_new_group_pa
and ext4_mb_new_inode_pa.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-19-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Kemeng Shi
fb28f9ceec ext4: remove unnecessary goto in ext4_mb_mark_diskspace_used
When ext4_read_block_bitmap fails, we can return PTR_ERR(bitmap_bh) to
remove unnecessary NULL check of bitmap_bh.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-18-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Kemeng Shi
c7f2bafa3c ext4: remove unnecessary count2 in ext4_free_data_in_buddy
count2 is always 1 in mb_debug, just remove unnecessary count2.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-17-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:12 -04:00
Kemeng Shi
df11909514 ext4: remove unnecessary exit_meta_group_info tag
We goto exit_meta_group_info only to return -ENOMEM. Return -ENOMEM
directly instead of goto to remove this unnecessary tag.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-16-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
78dc9f844f ext4: use best found when complex scan of group finishs
If any bex which meets bex->fe_len >= gex->fe_len is found, then it will
always be used when complex scan of group that bex belongs to finishs.
So there will not be any lock-unlock period.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-15-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
32c0869370 ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ext4_mb_check_limits
Only call trace of ext4_mb_check_limits is as following:
ext4_mb_complex_scan_group
	ext4_mb_measure_extent
		ext4_mb_check_limits(ac, e4b, 0);
	ext4_mb_check_limits(ac, e4b, 1);

If the first ac->ac_found > sbi->s_mb_max_to_scan check in
ext4_mb_check_limits is met, we will set ac_status to
AC_STATUS_BREAK and call ext4_mb_try_best_found to try to use
ac->ac_b_ex.
If ext4_mb_try_best_found successes, then block allocation finishs,
the removed ac->ac_found > sbi->s_mb_min_to_scan check is not reachable.
If ext4_mb_try_best_found fails, then we set EXT4_MB_HINT_FIRST and
reset ac->ac_b_ex to retry block allocation. We will use any found
free extent in ext4_mb_measure_extent before reach the removed
ac->ac_found > sbi->s_mb_min_to_scan check.
In summary, the removed ac->ac_found > sbi->s_mb_min_to_scan check is
not reachable and we can remove that dead check.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-14-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
976620bd26 ext4: remove dead check in mb_buddy_mark_free
We always adjust first to even number and adjust last to odd number, so
first == last will never happen. Remove this dead check.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-13-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
aaae558dae ext4: remove unnecessary check in ext4_mb_new_blocks
1. remove unnecessary ac check:
We always go to out tag before ac is successfully allocated, then we can
move out tag after free of ac and remove NULL check of ac.

2. remove unnecessary *errp check:
We always go to errout tag if *errp is non-zero, then we can move errout
tag into error handle if *errp is non-zero.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-12-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
285164b801 ext4: remove unnecessary e4b->bd_buddy_page check in ext4_mb_load_buddy_gfp
e4b->bd_buddy_page is only set if we initialize ext4_buddy successfully. So
e4b->bd_buddy_page is always NULL in error handle branch. Just remove the
dead check.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-11-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
139f46d3b5 ext4: Remove unnecessary release when memory allocation failed in ext4_mb_init_cache
If we alloc array of buffer_head failed, there is no resource need to be
freed and we can simpily return error.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-10-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
85b67ffb7d ext4: remove unused return value of ext4_mb_try_best_found and ext4_mb_free_metadata
Return value static function ext4_mb_try_best_found and
ext4_mb_free_metadata is not used. Just remove unused return value.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-9-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
1b5c9d3494 ext4: add missed brelse in ext4_free_blocks_simple
Release bitmap buffer_head we got if error occurs.
Besides, this patch remove unused assignment to err.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-8-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
36cb0f52ae ext4: protect pa->pa_free in ext4_discard_allocated_blocks
If ext4_mb_mark_diskspace_used fails in ext4_mb_new_blocks, we may
discard pa already in list. Protect pa with pa_lock to avoid race.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-7-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
1afdc58894 ext4: correct start of used group pa for debug in ext4_mb_use_group_pa
As we don't correct pa_lstart here, so there is no need to subtract
pa_lstart with consumed len.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-6-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
abc075d4a5 ext4: correct calculation of s_mb_preallocated
We will add pa_free to s_mb_preallocated when new ext4_prealloc_space is
created. In ext4_mb_new_inode_pa, we will call ext4_mb_use_inode_pa
before adding pa_free to s_mb_preallocated. However, ext4_mb_use_inode_pa
will consume pa_free for block allocation which triggerred the creation
of ext4_prealloc_space. Add pa_free to s_mb_preallocated before
ext4_mb_use_inode_pa to correct calculation of s_mb_preallocated.
There is no such problem in ext4_mb_new_group_pa as pa_free of group pa
is consumed in ext4_mb_release_context instead of ext4_mb_use_group_pa.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-5-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
22fab98402 ext4: get correct ext4_group_info in ext4_mb_prefetch_fini
We always get ext4_group_desc with group + 1 and ext4_group_info with
group to check if we need do initialize ext4_group_info for the group.
Just get ext4_group_desc with group for ext4_group_info initialization
check.

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-4-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:11 -04:00
Kemeng Shi
01e4ca2945 ext4: allow to find by goal if EXT4_MB_HINT_GOAL_ONLY is set
If EXT4_MB_HINT_GOAL_ONLY is set, ext4_mb_regular_allocator will only
allocate blocks from ext4_mb_find_by_goal. Allow to find by goal in
ext4_mb_find_by_goal if EXT4_MB_HINT_GOAL_ONLY is set or allocation
with EXT4_MB_HINT_GOAL_ONLY set will always fail.

EXT4_MB_HINT_GOAL_ONLY is not used at all, so the problem is not
found for now.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:10 -04:00
Kemeng Shi
b07ffe6927 ext4: set goal start correctly in ext4_mb_normalize_request
We need to set ac_g_ex to notify the goal start used in
ext4_mb_find_by_goal. Set ac_g_ex instead of ac_f_ex in
ext4_mb_normalize_request.
Besides we should assure goal start is in range [first_data_block,
blocks_count) as ext4_mb_initialize_context does.

[ Added a check to make sure size is less than ar->pright; otherwise
  we could end up passing an underflowed value of ar->pright - size to
  ext4_get_group_no_and_offset(), which will trigger a BUG_ON later on.
  - TYT ]

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-06 01:13:03 -04:00
Kemeng Shi
1df9bde48f ext4: remove unused group parameter in ext4_block_bitmap_csum_set
Remove unused group parameter in ext4_block_bitmap_csum_set. After this,
group parameter in ext4_set_bitmap_checksums is also not used, just
remove it too.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230221203027.2359920-5-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-03-23 23:00:08 -04:00
Guoqing Jiang
d73eff68a8 ext4: make ext4_mb_initialize_context return void
Change the return type to void since it always return 0, and no need
to do the checking in ext4_mb_new_blocks.

Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20221202120409.24098-1-guoqing.jiang@linux.dev
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-12-08 21:49:25 -05:00
Jan Kara
a078dff870 ext4: fixup possible uninitialized variable access in ext4_mb_choose_next_group_cr1()
Variable 'grp' may be left uninitialized if there's no group with
suitable average fragment size (or larger). Fix the problem by
initializing it earlier.

Link: https://lore.kernel.org/r/20220922091542.pkhedytey7wzp5fi@quack3
Fixes: 83e80a6e35 ("ext4: use buckets for cr 1 block scan instead of rbtree")
Cc: stable@kernel.org
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-09-26 13:21:05 -04:00
Theodore Ts'o
80fa46d6b9 ext4: limit the number of retries after discarding preallocations blocks
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
2022-09-22 10:51:19 -04:00
Jan Kara
83e80a6e35 ext4: use buckets for cr 1 block scan instead of rbtree
Using rbtree for sorting groups by average fragment size is relatively
expensive (needs rbtree update on every block freeing or allocation) and
leads to wide spreading of allocations because selection of block group
is very sentitive both to changes in free space and amount of blocks
allocated. Furthermore selecting group with the best matching average
fragment size is not necessary anyway, even more so because the
variability of fragment sizes within a group is likely large so average
is not telling much. We just need a group with large enough average
fragment size so that we have high probability of finding large enough
free extent and we don't want average fragment size to be too big so
that we are likely to find free extent only somewhat larger than what we
need.

So instead of maintaing rbtree of groups sorted by fragment size keep
bins (lists) or groups where average fragment size is in the interval
[2^i, 2^(i+1)). This structure requires less updates on block allocation
/ freeing, generally avoids chaotic spreading of allocations into block
groups, and still is able to quickly (even faster that the rbtree)
provide a block group which is likely to have a suitably sized free
space extent.

This patch reduces number of block groups used when untarring archive
with medium sized files (size somewhat above 64k which is default
mballoc limit for avoiding locality group preallocation) to about half
and thus improves write speeds for eMMC flash significantly.

Fixes: 196e402adf ("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>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/all/0d81a7c2-46b7-6010-62a4-3e6cfc1628d6@i2se.com/
Link: https://lore.kernel.org/r/20220908092136.11770-5-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-09-21 22:12:03 -04:00
Jan Kara
a9f2a2931d ext4: use locality group preallocation for small closed files
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: 196e402adf ("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>
2022-09-21 22:12:00 -04:00
Jan Kara
1940265ede ext4: avoid unnecessary spreading of allocations among groups
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: 196e402adf ("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>
2022-09-21 22:11:41 -04:00
Jan Kara
4fca50d440 ext4: make mballoc try target group first even with mb_optimize_scan
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: 196e402adf ("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>
2022-09-21 22:11:34 -04:00
Lukas Czerner
1e1c2b86ef ext4: block range must be validated before use in ext4_mb_clear_bb()
Block range to free is validated in ext4_free_blocks() using
ext4_inode_block_valid() and then it's passed to ext4_mb_clear_bb().
However in some situations on bigalloc file system the range might be
adjusted after the validation in ext4_free_blocks() which can lead to
troubles on corrupted file systems such as one found by syzkaller that
resulted in the following BUG

kernel BUG at fs/ext4/ext4.h:3319!
PREEMPT SMP NOPTI
CPU: 28 PID: 4243 Comm: repro Kdump: loaded Not tainted 5.19.0-rc6+ #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
RIP: 0010:ext4_free_blocks+0x95e/0xa90
Call Trace:
 <TASK>
 ? lock_timer_base+0x61/0x80
 ? __es_remove_extent+0x5a/0x760
 ? __mod_timer+0x256/0x380
 ? ext4_ind_truncate_ensure_credits+0x90/0x220
 ext4_clear_blocks+0x107/0x1b0
 ext4_free_data+0x15b/0x170
 ext4_ind_truncate+0x214/0x2c0
 ? _raw_spin_unlock+0x15/0x30
 ? ext4_discard_preallocations+0x15a/0x410
 ? ext4_journal_check_start+0xe/0x90
 ? __ext4_journal_start_sb+0x2f/0x110
 ext4_truncate+0x1b5/0x460
 ? __ext4_journal_start_sb+0x2f/0x110
 ext4_evict_inode+0x2b4/0x6f0
 evict+0xd0/0x1d0
 ext4_enable_quotas+0x11f/0x1f0
 ext4_orphan_cleanup+0x3de/0x430
 ? proc_create_seq_private+0x43/0x50
 ext4_fill_super+0x295f/0x3ae0
 ? snprintf+0x39/0x40
 ? sget_fc+0x19c/0x330
 ? ext4_reconfigure+0x850/0x850
 get_tree_bdev+0x16d/0x260
 vfs_get_tree+0x25/0xb0
 path_mount+0x431/0xa70
 __x64_sys_mount+0xe2/0x120
 do_syscall_64+0x5b/0x80
 ? do_user_addr_fault+0x1e2/0x670
 ? exc_page_fault+0x70/0x170
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fdf4e512ace

Fix it by making sure that the block range is properly validated before
used every time it changes in ext4_free_blocks() or ext4_mb_clear_bb().

Link: https://syzkaller.appspot.com/bug?id=5266d464285a03cee9dbfda7d2452a72c3c2ae7c
Reported-by: syzbot+15cd994e273307bf5cfa@syzkaller.appspotmail.com
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Tadeusz Struk <tadeusz.struk@linaro.org>
Tested-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Link: https://lore.kernel.org/r/20220714165903.58260-1-lczerner@redhat.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-08-02 23:56:25 -04:00
hanjinke
218a69441b ext4: reuse order and buddy in mb_mark_used when buddy split
After each buddy split, mb_mark_used will search the proper order
for the block which may consume some loop in mb_find_order_for_block.
In fact, we can reuse the order and buddy generated by the buddy split.

Reviewed by: lei.rao@intel.com
Signed-off-by: hanjinke <hanjinke.666@bytedance.com>
Link: https://lore.kernel.org/r/20220606155305.74146-1-hanjinke.666@bytedance.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-08-02 23:52:19 -04:00
Baokun Li
cf4ff938b4 ext4: correct the judgment of BUG in ext4_mb_normalize_request
ext4_mb_normalize_request() can move logical start of allocated blocks
to reduce fragmentation and better utilize preallocation. However logical
block requested as a start of allocation (ac->ac_o_ex.fe_logical) should
always be covered by allocated blocks so we should check that by
modifying and to or in the assertion.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Ritesh Harjani <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220528110017.354175-3-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-06-18 19:35:57 -04:00
Baokun Li
a08f789d2a ext4: fix bug_on ext4_mb_use_inode_pa
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: cd648b8a8f ("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>
2022-06-18 19:35:43 -04:00
Linus Torvalds
fea3043314 Various bug fixes and cleanups for ext4. In particular, move the
crypto related fucntions from fs/ext4/super.c into a new
 fs/ext4/crypto.c, and fix a number of bugs found by fuzzers and error
 injection tools.
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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:
 "Various bug fixes and cleanups for ext4.

  In particular, move the crypto related fucntions from fs/ext4/super.c
  into a new fs/ext4/crypto.c, and fix a number of bugs found by fuzzers
  and error injection tools"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits)
  ext4: only allow test_dummy_encryption when supported
  ext4: fix bug_on in __es_tree_search
  ext4: avoid cycles in directory h-tree
  ext4: verify dir block before splitting it
  ext4: filter out EXT4_FC_REPLAY from on-disk superblock field s_state
  ext4: fix bug_on in ext4_writepages
  ext4: refactor and move ext4_ioctl_get_encryption_pwsalt()
  ext4: cleanup function defs from ext4.h into crypto.c
  ext4: move ext4 crypto code to its own file crypto.c
  ext4: fix memory leak in parse_apply_sb_mount_options()
  ext4: reject the 'commit' option on ext2 filesystems
  ext4: remove duplicated #include of dax.h in inode.c
  ext4: fix race condition between ext4_write and ext4_convert_inline_data
  ext4: convert symlink external data block mapping to bdev
  ext4: add nowait mode for ext4_getblk()
  ext4: fix journal_ioprio mount option handling
  ext4: mark group as trimmed only if it was fully scanned
  ext4: fix use-after-free in ext4_rename_dir_prepare
  ext4: add unmount filesystem message
  ext4: remove unnecessary conditionals
  ...
2022-05-24 19:04:46 -07:00
Dmitry Monakhov
d63c00ea43 ext4: mark group as trimmed only if it was fully scanned
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
2022-05-17 14:17:21 -04:00
Jinke Han
af2b327581 ext4: remove unnecessary code in __mb_check_buddy
When enter elseif branch, the the MB_CHECK_ASSERT will never fail.
In addtion, the only illegal combination is 0/0, which can be caught
by the first if branch.

Signed-off-by: Jinke Han <hanjinke.666@bytedance.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220404152243.13556-1-hanjinke.666@bytedance.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-05-11 15:19:06 -04:00
Yu Zhe
c30365b90a ext4: remove unnecessary type castings
remove unnecessary void* type castings.

Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
Link: https://lore.kernel.org/r/20220401081321.73735-1-yuzhe@nfschina.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-05-11 15:19:06 -04:00
Christoph Hellwig
44abff2c0b block: decouple REQ_OP_SECURE_ERASE from REQ_OP_DISCARD
Secure erase is a very different operation from discard in that it is
a data integrity operation vs hint.  Fully split the limits and helper
infrastructure to make the separation more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> [nifs2]
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org> [f2fs]
Acked-by: Coly Li <colyli@suse.de> [bcache]
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Chao Yu <chao@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220415045258.199825-27-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-17 19:49:59 -06:00
Christoph Hellwig
7b47ef52d0 block: add a bdev_discard_granularity helper
Abstract away implementation details from file systems by providing a
block_device based helper to retrieve the discard granularity.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> [drbd]
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Link: https://lore.kernel.org/r/20220415045258.199825-26-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-04-17 19:49:59 -06:00