kernel/linux.git/fs/ocfs2/suballoc.c, branch v7.0.10

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

ocfs2: detect released suballocator BG for fh_to_[dentry|parent]

2026-01-21T03:44:16+00:00

After ocfs2 gained the ability to reclaim suballocator free block group (BGs), a suballocator block group may be released. This change causes the xfstest case generic/426 to fail. generic/426 expects return value -ENOENT or -ESTALE, but the current code triggers -EROFS. Call stack before ocfs2 gained the ability to reclaim bg: ocfs2_fh_to_dentry //or ocfs2_fh_to_parent ocfs2_get_dentry + ocfs2_test_inode_bit | ocfs2_test_suballoc_bit | + ocfs2_read_group_descriptor //Since ocfs2 never releases the bg, | | //the bg block was always found. | + *res = ocfs2_test_bit //unlink was called, and the bit is zero | + if (!set) //because the above *res is 0 status = -ESTALE //the generic/426 expected return value Current call stack that triggers -EROFS: ocfs2_get_dentry ocfs2_test_inode_bit ocfs2_test_suballoc_bit ocfs2_read_group_descriptor + if reading a released bg, validation fails and triggers -EROFS How to fix: Since the read BG is already released, we must avoid triggering -EROFS. With this commit, we use ocfs2_read_hint_group_descriptor() to detect the released BG block. This approach quietly handles this type of error and returns -EINVAL, which triggers the caller's existing conversion path to -ESTALE. [dan.carpenter@linaro.org: fix uninitialized variable] Link: https://lkml.kernel.org/r/dc37519fd2470909f8c65e26c5131b8b6dde2a5c.1766043917.git.dan.carpenter@linaro.org Link: https://lkml.kernel.org/r/20251212074505.25962-3-heming.zhao@suse.com Signed-off-by: Heming Zhao Signed-off-by: Dan Carpenter Reviewed-by: Su Yue Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Heming Zhao Signed-off-by: Andrew Morton

ocfs2: give ocfs2 the ability to reclaim suballocator free bg

2026-01-21T03:44:16+00:00

Patch series "ocfs2: give ocfs2 the ability to reclaim suballocator free bg", v6. This patch (of 2): The current ocfs2 code can't reclaim suballocator block group space. In some cases, this causes ocfs2 to hold onto a lot of space. For example, when creating lots of small files, the space is held/managed by the '//inode_alloc'. After the user deletes all the small files, the space never returns to the '//global_bitmap'. This issue prevents ocfs2 from providing the needed space even when there is enough free space in a small ocfs2 volume. This patch gives ocfs2 the ability to reclaim suballocator free space when the block group is freed. For performance reasons, this patch keeps the first suballocator block group active. Link: https://lkml.kernel.org/r/20251212074505.25962-2-heming.zhao@suse.com Signed-off-by: Heming Zhao Reviewed-by: Su Yue Reviewed-by: Joseph Qi Cc: Changwei Ge Cc: Joel Becker Cc: Jun Piao Cc: Junxiao Bi Cc: Mark Fasheh Signed-off-by: Andrew Morton

ocfs2: fix kernel BUG in ocfs2_find_victim_chain

2025-12-11T00:07:42+00:00

syzbot reported a kernel BUG in ocfs2_find_victim_chain() because the `cl_next_free_rec` field of the allocation chain list (next free slot in the chain list) is 0, triggring the BUG_ON(!cl->cl_next_free_rec) condition in ocfs2_find_victim_chain() and panicking the kernel. To fix this, an if condition is introduced in ocfs2_claim_suballoc_bits(), just before calling ocfs2_find_victim_chain(), the code block in it being executed when either of the following conditions is true: 1. `cl_next_free_rec` is equal to 0, indicating that there are no free chains in the allocation chain list 2. `cl_next_free_rec` is greater than `cl_count` (the total number of chains in the allocation chain list) Either of them being true is indicative of the fact that there are no chains left for usage. This is addressed using ocfs2_error(), which prints the error log for debugging purposes, rather than panicking the kernel. Link: https://lkml.kernel.org/r/20251201130711.143900-1-activprithvi@gmail.com Signed-off-by: Prithvi Tambewagh Reported-by: syzbot+96d38c6e1655c1420a72@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=96d38c6e1655c1420a72 Tested-by: syzbot+96d38c6e1655c1420a72@syzkaller.appspotmail.com Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Heming Zhao Cc: Signed-off-by: Andrew Morton

ocfs2: replace deprecated strcpy with strscpy

2025-12-11T00:07:42+00:00

strcpy() has been deprecated [1] because it performs no bounds checking on the destination buffer, which can lead to buffer overflows. Replace it with the safer strscpy(). No functional changes. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy [1] Link: https://lkml.kernel.org/r/20251126114419.92539-1-thorsten.blum@linux.dev Signed-off-by: Thorsten Blum Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Signed-off-by: Andrew Morton

ocfs2: fix the issue with discontiguous allocation in the global_bitmap

2025-05-08T06:39:37+00:00

commit 4eb7b93e0310 ("ocfs2: improve write IO performance when fragmentation is high") introduced another regression. The following ocfs2-test case can trigger this issue: > discontig_runner.sh => activate_discontig_bg.sh => resv_unwritten: > ${RESV_UNWRITTEN_BIN} -f ${WORK_PLACE}/large_testfile -s 0 -l \ > $((${FILE_MAJOR_SIZE_M}*1024*1024)) In my env, test disk size (by "fdisk -l "): > 53687091200 bytes, 104857600 sectors. Above command is: > /usr/local/ocfs2-test/bin/resv_unwritten -f \ > /mnt/ocfs2/ocfs2-activate-discontig-bg-dir/large_testfile -s 0 -l \ > 53187969024 Error log: > [*] Reserve 50724M space for a LARGE file, reserve 200M space for future test. > ioctl error 28: "No space left on device" > resv allocation failed Unknown error -1 > reserve unwritten region from 0 to 53187969024. Call flow: __ocfs2_change_file_space //by ioctl OCFS2_IOC_RESVSP64 ocfs2_allocate_unwritten_extents //start:0 len:53187969024 while() + ocfs2_get_clusters //cpos:0, alloc_size:1623168 (cluster number) + ocfs2_extend_allocation + ocfs2_lock_allocators | + choose OCFS2_AC_USE_MAIN & ocfs2_cluster_group_search | + ocfs2_add_inode_data ocfs2_add_clusters_in_btree __ocfs2_claim_clusters ocfs2_claim_suballoc_bits + During the allocation of the final part of the large file (after ~47GB), no chain had the required contiguous bits_wanted. Consequently, the allocation failed. How to fix: When OCFS2 is encountering fragmented allocation, the file system should stop attempting bits_wanted contiguous allocation and instead provide the largest available contiguous free bits from the cluster groups. Link: https://lkml.kernel.org/r/20250414060125.19938-2-heming.zhao@suse.com Fixes: 4eb7b93e0310 ("ocfs2: improve write IO performance when fragmentation is high") Signed-off-by: Heming Zhao Reported-by: Gautham Ananthakrishna Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Jun Piao Cc: Signed-off-by: Andrew Morton

ocfs2: speed up chain-list searching

2024-04-26T04:07:04+00:00

Add short-circuit code to speed up searching Link: https://lkml.kernel.org/r/20240328125203.20892-4-heming.zhao@suse.com Signed-off-by: Heming Zhao Reviewed-by: Joseph Qi Cc: Changwei Ge Cc: Gang He Cc: Joel Becker Cc: Jun Piao Cc: Junxiao Bi Cc: Mark Fasheh Signed-off-by: Andrew Morton

ocfs2: adjust enabling place for la window

2024-04-26T04:07:03+00:00

Patch series "improve write IO performance when fragmentation is high", v6. This patch (of 4): After introducing gd->bg_contig_free_bits, the code path 'ocfs2_cluster_group_search() => ocfs2_local_alloc_seen_free_bits()' becomes death when all the gd->bg_contig_free_bits are set to the correct value. This patch relocates ocfs2_local_alloc_seen_free_bits() to a more appropriate location. (The new place being ocfs2_block_group_set_bits().) In ocfs2_local_alloc_seen_free_bits(), the scope of the spin-lock has been adjusted to reduce meaningless lock races. e.g: when userspace creates & deletes 1 cluster_size files in parallel, acquiring the spin-lock in ocfs2_local_alloc_seen_free_bits() is totally pointless and impedes IO performance. Link: https://lkml.kernel.org/r/20240328125203.20892-3-heming.zhao@suse.com Signed-off-by: Heming Zhao Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Gang He Cc: Jun Piao Signed-off-by: Andrew Morton

ocfs2: improve write IO performance when fragmentation is high

2024-04-26T04:07:03+00:00

The group_search function ocfs2_cluster_group_search() should bypass groups with insufficient space to avoid unnecessary searches. This patch is particularly useful when ocfs2 is handling huge number small files, and volume fragmentation is very high. In this case, ocfs2 is busy with looking up available la window from //global_bitmap. This patch introduces a new member in the Group Description (gd) struct called 'bg_contig_free_bits', representing the max contigous free bits in this gd. When ocfs2 allocates a new la window from //global_bitmap, 'bg_contig_free_bits' helps expedite the search process. Let's image below path. 1. la state (->local_alloc_state) is set THROTTLED or DISABLED. 2. when user delete a large file and trigger ocfs2_local_alloc_seen_free_bits set osb->local_alloc_state unconditionally. 3. a write IOs thread run and trigger the worst performance path ``` ocfs2_reserve_clusters_with_limit ocfs2_reserve_local_alloc_bits ocfs2_local_alloc_slide_window //[1] + ocfs2_local_alloc_reserve_for_window //[2] + ocfs2_local_alloc_new_window //[3] ocfs2_recalc_la_window ``` [1]: will be called when la window bits used up. [2]: under la state is ENABLED, and this func only check global_bitmap free bits, it will succeed in general. [3]: will use the default la window size to search clusters then fail. ocfs2_recalc_la_window attempts other la window sizes. the timing complexity is O(n^4), resulting in a significant time cost for scanning global bitmap. This leads to a dramatic slowdown in write I/Os (e.g., user space 'dd'). i.e. an ocfs2 partition size: 1.45TB, cluster size: 4KB, la window default size: 106MB. The partition is fragmentation by creating & deleting huge mount of small files. before this patch, the timing of [3] should be (the number got from real world): - la window size change order (size: MB): 106, 53, 26.5, 13, 6.5, 3.25, 1.6, 0.8 only 0.8MB succeed, 0.8MB also triggers la window to disable. ocfs2_local_alloc_new_window retries 8 times, first 7 times totally runs in worst case. - group chain number: 242 ocfs2_claim_suballoc_bits calls for-loop 242 times - each chain has 49 block group ocfs2_search_chain calls while-loop 49 times - each bg has 32256 blocks ocfs2_block_group_find_clear_bits calls while-loop for 32256 bits. for ocfs2_find_next_zero_bit uses ffz() to find zero bit, let's use (32256/64) (this is not worst value) for timing calucation. the loop times: 7*242*49*(32256/64) = 41835024 (~42 million times) In the worst case, user space writes 1MB data will trigger 42M scanning times. under this patch, the timing is '7*242*49 = 83006', reduced by three orders of magnitude. Link: https://lkml.kernel.org/r/20240328125203.20892-2-heming.zhao@suse.com Signed-off-by: Heming Zhao Reviewed-by: Joseph Qi Cc: Changwei Ge Cc: Gang He Cc: Joel Becker Cc: Jun Piao Cc: Junxiao Bi Cc: Mark Fasheh Signed-off-by: Andrew Morton