summaryrefslogtreecommitdiffstats
path: root/fs/ext4/mballoc.c
Commit message (Collapse)AuthorAgeFilesLines
* ext4: remove a BUG_ON in ext4_mb_release_group_pa()Theodore Ts'o2023-05-131-1/+5
| | | | | | | | | | | | | | 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>
* ext4: allow ext4_get_group_info() to failTheodore Ts'o2023-05-131-11/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ext4: Remove the logic to trim inode PAsOjaswin Mujoo2023-04-061-20/+0
| | | | | | | | | | | | | | | | | 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>
* ext4: Use rbtrees to manage PAs instead of inode i_prealloc_listOjaswin Mujoo2023-04-061-79/+207
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ext4: Convert pa->pa_inode_list and pa->pa_obj_lock into a unionOjaswin Mujoo2023-04-061-32/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ** 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>
* ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()Ojaswin Mujoo2023-04-061-18/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ext4: Abstract out overlap fix/check logic in ext4_mb_normalize_request()Ojaswin Mujoo2023-04-061-41/+68
| | | | | | | | | | | | | | 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>
* ext4: Move overlap assert logic into a separate functionOjaswin Mujoo2023-04-061-11/+24
| | | | | | | | | | | | | | | 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>
* ext4: Refactor code in ext4_mb_normalize_request() and ↵Ojaswin Mujoo2023-04-061-47/+49
| | | | | | | | | | | | | | | 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>
* ext4: Refactor code related to freeing PAsOjaswin Mujoo2023-04-061-9/+21
| | | | | | | | | | | | | | | | | | | 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>
* ext4: Stop searching if PA doesn't satisfy non-extent fileOjaswin Mujoo2023-04-061-2/+7
| | | | | | | | | | | | | | | 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>
* ext4: convert some BUG_ON's in mballoc to use WARN_RATELIMITED insteadTheodore Ts'o2023-04-061-6/+19
| | | | | | | 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>
* ext4: avoid unnecessary pointer dereference in ext4_mb_normalize_requestKemeng Shi2023-04-061-5/+3
| | | | | | | | | | | 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>
* ext4: fix typos in mballocKemeng Shi2023-04-061-2/+2
| | | | | | | | | | 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>
* ext4: simplify calculation of blkoff in ext4_mb_new_blocks_simpleKemeng Shi2023-04-061-3/+2
| | | | | | | | | | 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>
* ext4: remove comment code ext4_discard_preallocationsKemeng Shi2023-04-061-1/+0
| | | | | | | | | 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>
* ext4: remove repeat assignment to ac_f_exKemeng Shi2023-04-061-8/+0
| | | | | | | | | | | | | | | | | | | | | | 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>
* ext4: remove unnecessary goto in ext4_mb_mark_diskspace_usedKemeng Shi2023-04-061-3/+1
| | | | | | | | | | 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>
* ext4: remove unnecessary count2 in ext4_free_data_in_buddyKemeng Shi2023-04-061-4/+2
| | | | | | | | | 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>
* ext4: remove unnecessary exit_meta_group_info tagKemeng Shi2023-04-061-2/+1
| | | | | | | | | | 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>
* ext4: use best found when complex scan of group finishsKemeng Shi2023-04-061-12/+2
| | | | | | | | | | | 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>
* ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ↵Kemeng Shi2023-04-061-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ext4: remove dead check in mb_buddy_mark_freeKemeng Shi2023-04-061-1/+2
| | | | | | | | | 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>
* ext4: remove unnecessary check in ext4_mb_new_blocksKemeng Shi2023-04-061-3/+2
| | | | | | | | | | | | | | | 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>
* ext4: remove unnecessary e4b->bd_buddy_page check in ext4_mb_load_buddy_gfpKemeng Shi2023-04-061-2/+1
| | | | | | | | | | | 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>
* ext4: Remove unnecessary release when memory allocation failed in ↵Kemeng Shi2023-04-061-4/+2
| | | | | | | | | | | | 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>
* ext4: remove unused return value of ext4_mb_try_best_found and ↵Kemeng Shi2023-04-061-7/+4
| | | | | | | | | | | | 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>
* ext4: add missed brelse in ext4_free_blocks_simpleKemeng Shi2023-04-061-3/+4
| | | | | | | | | | 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>
* ext4: protect pa->pa_free in ext4_discard_allocated_blocksKemeng Shi2023-04-061-1/+4
| | | | | | | | | | 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>
* ext4: correct start of used group pa for debug in ext4_mb_use_group_paKemeng Shi2023-04-061-1/+1
| | | | | | | | | | 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>
* ext4: correct calculation of s_mb_preallocatedKemeng Shi2023-04-061-1/+1
| | | | | | | | | | | | | | | | 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>
* ext4: get correct ext4_group_info in ext4_mb_prefetch_finiKemeng Shi2023-04-061-4/+4
| | | | | | | | | | | | | 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>
* ext4: allow to find by goal if EXT4_MB_HINT_GOAL_ONLY is setKemeng Shi2023-04-061-1/+1
| | | | | | | | | | | | | | | 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>
* ext4: set goal start correctly in ext4_mb_normalize_requestKemeng Shi2023-04-061-6/+10
| | | | | | | | | | | | | | | | | | 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>
* ext4: remove unused group parameter in ext4_block_bitmap_csum_setKemeng Shi2023-03-231-5/+5
| | | | | | | | | | | 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>
* ext4: make ext4_mb_initialize_context return voidGuoqing Jiang2022-12-081-8/+2
| | | | | | | | | | 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>
* ext4: fixup possible uninitialized variable access in ↵Jan Kara2022-09-261-2/+1
| | | | | | | | | | | | | | | 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: 83e80a6e3543 ("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>
* ext4: limit the number of retries after discarding preallocations blocksTheodore Ts'o2022-09-221-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* ext4: use buckets for cr 1 block scan instead of rbtreeJan Kara2022-09-211-143/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 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> 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>
* ext4: use locality group preallocation for small closed filesJan Kara2022-09-211-12/+15
| | | | | | | | | | | | | | | | | | | | | 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>
* ext4: avoid unnecessary spreading of allocations among groupsJan Kara2022-09-211-11/+13
| | | | | | | | | | | | | | | | | | | | | | 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>
* ext4: make mballoc try target group first even with mb_optimize_scanJan Kara2022-09-211-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ext4: block range must be validated before use in ext4_mb_clear_bb()Lukas Czerner2022-08-021-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ext4: reuse order and buddy in mb_mark_used when buddy splithanjinke2022-08-021-2/+8
| | | | | | | | | | | 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>
* ext4: correct the judgment of BUG in ext4_mb_normalize_requestBaokun Li2022-06-181-1/+16
| | | | | | | | | | | | | 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>
* ext4: fix bug_on ext4_mb_use_inode_paBaokun Li2022-06-181-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge tag 'ext4_for_linus' of ↵Linus Torvalds2022-05-241-11/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * ext4: mark group as trimmed only if it was fully scannedDmitry Monakhov2022-05-171-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * ext4: remove unnecessary code in __mb_check_buddyJinke Han2022-05-111-4/+1
| | | | | | | | | | | | | | | | | | | | | | 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>
| * ext4: remove unnecessary type castingsYu Zhe2022-05-111-1/+1
| | | | | | | | | | | | | | | | 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>
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-06 13:18:31 +0000