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2026-01-23et4: allow zeroout when doing written to unwritten splitOjaswin Mujoo
Currently, when we are doing an extent split and convert operation of written to unwritten extent (example, as done by ZERO_RANGE), we don't allow the zeroout fallback in case the extent tree manipulation fails. This is mostly because zeroout might take unsually long and the fact that this code path is more tolerant to failures than endio. Since we have zeroout machinery in place, we might as well use it hence lift this restriction. To mitigate zeroout taking too long respect the max zeroout limit here so that the operation finishes relatively fast. Also, add kunit tests for this case. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/1c3349020b8e098a63f293b84bc8a9b56011cef4.1769149131.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-23ext4: refactor split and convert extentsOjaswin Mujoo
ext4_split_convert_extents() has been historically prone to subtle bugs and inconsistent behavior due to the way all the various flags interact with the extent split and conversion process. For example, callers like ext4_convert_unwritten_extents_endio() and convert_initialized_extents() needed to open code extent conversion despite passing CONVERT or CONVERT_UNWRITTEN flags because ext4_split_convert_extents() wasn't performing the conversion. Hence, refactor ext4_split_convert_extents() to clearly enforce the semantics of each flag. The major changes here are: * Clearly separate the split and convert process: * ext4_split_extent() and ext4_split_extent_at() are now only responsible to perform the split. * ext4_split_convert_extents() is now responsible to perform extent conversion after calling ext4_split_extent() for splitting. * This helps get rid of all the MARK_UNWRIT* flags. * Clearly enforce the semantics of flags passed to ext4_split_convert_extents(): * EXT4_GET_BLOCKS_CONVERT: Will convert the split extent to written * EXT4_GET_BLOCKS_CONVERT_UNWRITTEN: Will convert the split extent to unwritten * Modify all callers to enforce the above semantics. * Use ext4_split_convert_extents() instead of ext4_split_extents() in ext4_ext_convert_to_initialized() for uniformity. * Now that ext4_split_convert_extents() is handling caching to es, we dont need to do it in ext4_split_extent_zeroout(). * Cleanup all callers open coding the conversion logic. Further, modify kuniy tests to pass flags based on the new semantics. >From an end user point of view, we should not see any changes in behavior of ext4. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/2084a383d69ceefbaa293b8fcf725365eca0a349.1769149131.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-23ext4: refactor zeroout path and handle all casesOjaswin Mujoo
Currently, zeroout is used as a fallback in case we fail to split/convert extents in the "traditional" modify-the-extent-tree way. This is essential to mitigate failures in critical paths like extent splitting during endio. However, the logic is very messy and not easy to follow. Further, the fragile use of various flags has made it prone to errors. Refactor zeroout out logic by moving it up to ext4_split_extents(). Further, zeroout correctly based on the type of conversion we want, ie: - unwritten to written: Zeroout everything around the mapped range. - written to unwritten: Zeroout only the mapped range. Also, ext4_ext_convert_to_initialized() now passes EXT4_GET_BLOCKS_CONVERT to make the intention clear. Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/e1b51dedeca7c0b1f702141d91edfe4230560e7b.1769149131.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-23ext4: propagate flags to ext4_convert_unwritten_extents_endio()Ojaswin Mujoo
Currently, callers like ext4_convert_unwritten_extents() pass EXT4_EX_NOCACHE flag to avoid caching extents however this is not respected by ext4_convert_unwritten_extents_endio(). Hence, modify it to accept flags from the caller and to pass the flags on to other extent manipulation functions it calls. This makes sure the NOCACHE flag is respected throughout the code path. Also, since the caller already passes METADATA_NOFAIL and CONVERT flags we don't need to explicitly pass it anymore. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/7c2139e0ad32c49c19b194f72219e15d613de284.1769149131.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-23ext4: propagate flags to convert_initialized_extent()Ojaswin Mujoo
Currently, ext4_zero_range passes EXT4_EX_NOCACHE flag to avoid caching extents however this is not respected by convert_initialized_extent(). Hence, modify it to accept flags from the caller and to pass the flags on to other extent manipulation functions it calls. This makes sure the NOCACHE flag is respected throughout the code path. Also, we no longer explicitly pass CONVERT_UNWRITTEN as the caller takes care of this. Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/07008fbb14db727fddcaf4c30e2346c49f6c8fe0.1769149131.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-23ext4: add extent status cache support to kunit testsOjaswin Mujoo
Add support in Kunit tests to ensure that the extent status cache is also in sync after the extent split and conversion operations. Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/5f9d2668feeb89a3f3e9d03dadab8c10cbea3741.1769149131.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-23ext4: kunit tests for extent splitting and conversionOjaswin Mujoo
Add multiple KUnit tests to test various permutations of extent splitting and conversion. We test the following cases: 1. Split of unwritten extent into 2 parts and convert 1 part to written 2. Split of unwritten extent into 3 parts and convert 1 part to written 3. Split of written extent into 2 parts and convert 1 part to unwritten 4. Split of written extent into 3 parts and convert 1 part to unwritten 5. Zeroout fallback for all the above cases except 3-4 because zeroout is not supported for written to unwritten splits The main function we test here is ext4_split_convert_extents(). Currently some of the tests are failing due to issues in implementation. All failures are mitigated at other layers in ext4 [1] but still point out the mismatch in expectation of what the caller wants vs what the function does. The aim is to eventually fix all the failures we see here. More detailed implementation notes can be found in the topmost commit in the test file. [1] for example, EXT4_GET_BLOCKS_CONVERT doesn't really convert the split extent to written, but rather the callers end up doing the conversion. Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/22bb9d17cd88c1318a2edde48887ca7488cb8a13.1769149131.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-19ext4: remove redundant NULL check after __GFP_NOFAILBaolin Liu
Remove redundant NULL check after kcalloc() with GFP_NOFS | __GFP_NOFAIL. Signed-off-by: Baolin Liu <liubaolin@kylinos.cn> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Link: https://patch.msgid.link/20260106062016.154573-1-liubaolin12138@163.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-19ext4: remove EXT4_GET_BLOCKS_IO_CREATE_EXTZhang Yi
We do not use EXT4_GET_BLOCKS_IO_CREATE_EXT or split extents before submitting I/O; therefore, remove the related code. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20260105014522.1937690-8-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-19ext4: don't split extent before submitting I/OZhang Yi
Currently, when writing back dirty pages to the filesystem with the dioread_nolock feature enabled and when doing DIO, if the area to be written back is part of an unwritten extent, the EXT4_GET_BLOCKS_IO_CREATE_EXT flag is set during block allocation before submitting I/O. The function ext4_split_convert_extents() then attempts to split this extent in advance. This approach is designed to prevents extent splitting and conversion to the written type from failing due to insufficient disk space at the time of I/O completion, which could otherwise result in data loss. However, we already have two mechanisms to ensure successful extent conversion. The first is the EXT4_GET_BLOCKS_METADATA_NOFAIL flag, which is a best effort, it permits the use of 2% of the reserved space or 4,096 blocks in the file system when splitting extents. This flag covers most scenarios where extent splitting might fail. The second is the EXT4_EXT_MAY_ZEROOUT flag, which is also set during extent splitting. If the reserved space is insufficient and splitting fails, it does not retry the allocation. Instead, it directly zeros out the extra part of the extent, thereby avoiding splitting and directly converting the entire extent to the written type. These two mechanisms also exist when I/Os are completed because there is a concurrency window between write-back and fallocate, which may still require us to split extents upon I/O completion. There is no much difference between splitting extents before submitting I/O. Therefore, It seems possible to defer the splitting until I/O completion, it won't increase the risk of I/O failure and data loss. On the contrary, if some I/Os can be merged when I/O completion, it can also reduce unnecessary splitting operations, thereby alleviating the pressure on reserved space. In addition, deferring extent splitting until I/O completion can also simplify the IO submission process and avoid initiating unnecessary journal handles when writing unwritten extents. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20260105014522.1937690-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-19ext4: use reserved metadata blocks when splitting extent on endioZhang Yi
When performing buffered writes, we may need to split and convert an unwritten extent into a written one during the end I/O process. However, we do not reserve space specifically for these metadata changes, we only reserve 2% of space or 4096 blocks. To address this, we use EXT4_GET_BLOCKS_PRE_IO to potentially split extents in advance and EXT4_GET_BLOCKS_METADATA_NOFAIL to utilize reserved space if necessary. These two approaches can reduce the likelihood of running out of space and losing data. However, these methods are merely best efforts, we could still run out of space, and there is not much difference between converting an extent during the writeback process and the end I/O process, it won't increase the risk of losing data if we postpone the conversion. Therefore, also use EXT4_GET_BLOCKS_METADATA_NOFAIL in ext4_convert_unwritten_extents_endio() to prepare for the buffered I/O iomap conversion, which may perform extent conversion during the end I/O process. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20260105014522.1937690-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-19ext4: fix memory leak in ext4_ext_shift_extents()Zilin Guan
In ext4_ext_shift_extents(), if the extent is NULL in the while loop, the function returns immediately without releasing the path obtained via ext4_find_extent(), leading to a memory leak. Fix this by jumping to the out label to ensure the path is properly released. Fixes: a18ed359bdddc ("ext4: always check ext4_ext_find_extent result") Signed-off-by: Zilin Guan <zilin@seu.edu.cn> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Link: https://patch.msgid.link/20251225084800.905701-1-zilin@seu.edu.cn Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2026-01-18ext4: replace ext4_es_insert_extent() when caching on-disk extentsZhang Yi
In ext4, the remaining places for inserting extents into the extent status tree within ext4_ext_determine_insert_hole() and ext4_map_query_blocks() directly cache on-disk extents. We can use ext4_es_cache_extent() instead of ext4_es_insert_extent() in these cases. This will help reduce unnecessary increases in extent sequence numbers and cache invalidations after supporting IOMAP in the future. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Message-ID: <20251129103247.686136-14-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-18ext4: cleanup zeroout in ext4_split_extent_at()Zhang Yi
zero_ex is a temporary variable used only for writing zeros and inserting extent status entry, it will not be directly inserted into the tree. Therefore, it can be assigned values from the target extent in various scenarios, eliminating the need to explicitly assign values to each variable individually. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Baokun Li <libaokun1@huawei.com> Message-ID: <20251129103247.686136-9-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-18ext4: drop extent cache when splitting extent failsZhang Yi
When the split extent fails, we might leave some extents still being processed and return an error directly, which will result in stale extent entries remaining in the extent status tree. So drop all of the remaining potentially stale extents if the splitting fails. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Cc: stable@kernel.org Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Message-ID: <20251129103247.686136-8-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-18ext4: drop extent cache after doing PARTIAL_VALID1 zerooutZhang Yi
When splitting an unwritten extent in the middle and converting it to initialized in ext4_split_extent() with the EXT4_EXT_MAY_ZEROOUT and EXT4_EXT_DATA_VALID2 flags set, it could leave a stale unwritten extent. Assume we have an unwritten file and buffered write in the middle of it without dioread_nolock enabled, it will allocate blocks as written extent. 0 A B N [UUUUUUUUUUUU] on-disk extent U: unwritten extent [UUUUUUUUUUUU] extent status tree [--DDDDDDDD--] D: valid data |<- ->| ----> this range needs to be initialized ext4_split_extent() first try to split this extent at B with EXT4_EXT_DATA_PARTIAL_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but ext4_split_extent_at() failed to split this extent due to temporary lack of space. It zeroout B to N and leave the entire extent as unwritten. 0 A B N [UUUUUUUUUUUU] on-disk extent [UUUUUUUUUUUU] extent status tree [--DDDDDDDDZZ] Z: zeroed data ext4_split_extent() then try to split this extent at A with EXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and leave an written extent from A to N. 0 A B N [UUWWWWWWWWWW] on-disk extent W: written extent [UUUUUUUUUUUU] extent status tree [--DDDDDDDDZZ] Finally ext4_map_create_blocks() only insert extent A to B to the extent status tree, and leave an stale unwritten extent in the status tree. 0 A B N [UUWWWWWWWWWW] on-disk extent W: written extent [UUWWWWWWWWUU] extent status tree [--DDDDDDDDZZ] Fix this issue by always cached extent status entry after zeroing out the second part. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Cc: stable@kernel.org Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Message-ID: <20251129103247.686136-7-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-18ext4: don't cache extent during splitting extentZhang Yi
Caching extents during the splitting process is risky, as it may result in stale extents remaining in the status tree. Moreover, in most cases, the corresponding extent block entries are likely already cached before the split happens, making caching here not particularly useful. Assume we have an unwritten extent, and then DIO writes the first half. [UUUUUUUUUUUUUUUU] on-disk extent U: unwritten extent [UUUUUUUUUUUUUUUU] extent status tree |<- ->| ----> dio write this range First, when ext4_split_extent_at() splits this extent, it truncates the existing extent and then inserts a new one. During this process, this extent status entry may be shrunk, and calls to ext4_find_extent() and ext4_cache_extents() may occur, which could potentially insert the truncated range as a hole into the extent status tree. After the split is completed, this hole is not replaced with the correct status. [UUUUUUU|UUUUUUUU] on-disk extent U: unwritten extent [UUUUUUU|HHHHHHHH] extent status tree H: hole Then, the outer calling functions will not correct this remaining hole extent either. Finally, if we perform a delayed buffer write on this latter part, it will re-insert the delayed extent and cause an error in space accounting. In adition, if the unwritten extent cache is not shrunk during the splitting, ext4_cache_extents() also conflicts with existing extents when caching extents. In the future, we will add checks when caching extents, which will trigger a warning. Therefore, Do not cache extents that are being split. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Cc: stable@kernel.org Message-ID: <20251129103247.686136-6-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-18ext4: correct the mapping status if the extent has been zeroedZhang Yi
Before submitting I/O and allocating blocks with the EXT4_GET_BLOCKS_PRE_IO flag set, ext4_split_convert_extents() may convert the target extent range to initialized due to ENOSPC, ENOMEM, or EQUOTA errors. However, it still marks the mapping as incorrectly unwritten. Although this may not seem to cause any practical problems, it will result in an unnecessary extent conversion operation after I/O completion. Therefore, it's better to correct the returned mapping status. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Message-ID: <20251129103247.686136-5-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-18ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/OZhang Yi
When allocating blocks during within-EOF DIO and writeback with dioread_nolock enabled, EXT4_GET_BLOCKS_PRE_IO was set to split an existing large unwritten extent. However, EXT4_GET_BLOCKS_CONVERT was set when calling ext4_split_convert_extents(), which may potentially result in stale data issues. Assume we have an unwritten extent, and then DIO writes the second half. [UUUUUUUUUUUUUUUU] on-disk extent U: unwritten extent [UUUUUUUUUUUUUUUU] extent status tree |<- ->| ----> dio write this range First, ext4_iomap_alloc() call ext4_map_blocks() with EXT4_GET_BLOCKS_PRE_IO, EXT4_GET_BLOCKS_UNWRIT_EXT and EXT4_GET_BLOCKS_CREATE flags set. ext4_map_blocks() find this extent and call ext4_split_convert_extents() with EXT4_GET_BLOCKS_CONVERT and the above flags set. Then, ext4_split_convert_extents() calls ext4_split_extent() with EXT4_EXT_MAY_ZEROOUT, EXT4_EXT_MARK_UNWRIT2 and EXT4_EXT_DATA_VALID2 flags set, and it calls ext4_split_extent_at() to split the second half with EXT4_EXT_DATA_VALID2, EXT4_EXT_MARK_UNWRIT1, EXT4_EXT_MAY_ZEROOUT and EXT4_EXT_MARK_UNWRIT2 flags set. However, ext4_split_extent_at() failed to insert extent since a temporary lack -ENOSPC. It zeroes out the first half but convert the entire on-disk extent to written since the EXT4_EXT_DATA_VALID2 flag set, but left the second half as unwritten in the extent status tree. [0000000000SSSSSS] data S: stale data, 0: zeroed [WWWWWWWWWWWWWWWW] on-disk extent W: written extent [WWWWWWWWWWUUUUUU] extent status tree Finally, if the DIO failed to write data to the disk, the stale data in the second half will be exposed once the cached extent entry is gone. Fix this issue by not passing EXT4_GET_BLOCKS_CONVERT when splitting an unwritten extent before submitting I/O, and make ext4_split_convert_extents() to zero out the entire extent range to zero for this case, and also mark the extent in the extent status tree for consistency. Fixes: b8a8684502a0 ("ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate") Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Cc: stable@kernel.org Message-ID: <20251129103247.686136-4-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-18ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1Zhang Yi
When allocating initialized blocks from a large unwritten extent, or when splitting an unwritten extent during end I/O and converting it to initialized, there is currently a potential issue of stale data if the extent needs to be split in the middle. 0 A B N [UUUUUUUUUUUU] U: unwritten extent [--DDDDDDDD--] D: valid data |<- ->| ----> this range needs to be initialized ext4_split_extent() first try to split this extent at B with EXT4_EXT_DATA_ENTIRE_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but ext4_split_extent_at() failed to split this extent due to temporary lack of space. It zeroout B to N and mark the entire extent from 0 to N as written. 0 A B N [WWWWWWWWWWWW] W: written extent [SSDDDDDDDDZZ] Z: zeroed, S: stale data ext4_split_extent() then try to split this extent at A with EXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and left a stale written extent from 0 to A. 0 A B N [WW|WWWWWWWWWW] [SS|DDDDDDDDZZ] Fix this by pass EXT4_EXT_DATA_PARTIAL_VALID1 to ext4_split_extent_at() when splitting at B, don't convert the entire extent to written and left it as unwritten after zeroing out B to N. The remaining work is just like the standard two-part split. ext4_split_extent() will pass the EXT4_EXT_DATA_VALID2 flag when it calls ext4_split_extent_at() for the second time, allowing it to properly handle the split. If the split is successful, it will keep extent from 0 to A as unwritten. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Cc: stable@kernel.org Message-ID: <20251129103247.686136-3-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-01-18ext4: subdivide EXT4_EXT_DATA_VALID1Zhang Yi
When splitting an extent, if the EXT4_GET_BLOCKS_CONVERT flag is set and it is necessary to split the target extent in the middle, ext4_split_extent() first handles splitting the latter half of the extent and passes the EXT4_EXT_DATA_VALID1 flag. This flag implies that all blocks before the split point contain valid data; however, this assumption is incorrect. Therefore, subdivid EXT4_EXT_DATA_VALID1 into EXT4_EXT_DATA_ENTIRE_VALID1 and EXT4_EXT_DATA_PARTIAL_VALID1, which indicate that the first half of the extent is either entirely valid or only partially valid, respectively. These two flags cannot be set simultaneously. This patch does not use EXT4_EXT_DATA_PARTIAL_VALID1, it only replaces EXT4_EXT_DATA_VALID1 with EXT4_EXT_DATA_ENTIRE_VALID1 at the location where it is set, no logical changes. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Cc: stable@kernel.org Message-ID: <20251129103247.686136-2-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-11-28ext4: add EXT4_LBLK_TO_B macro for logical block to bytes conversionBaokun Li
No functional changes. Signed-off-by: Baokun Li <libaokun1@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Message-ID: <20251121090654.631996-10-libaokun@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-11-26ext4: correct the comments place for EXT4_EXT_MAY_ZEROOUTYang Erkun
Move the comments just before we set EXT4_EXT_MAY_ZEROOUT in ext4_split_convert_extents. Signed-off-by: Yang Erkun <yangerkun@huawei.com> Message-ID: <20251112084538.1658232-4-yangerkun@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-11-26ext4: rename EXT4_GET_BLOCKS_PRE_IOYang Erkun
This flag has been generalized to split an unwritten extent when we do dio or dioread_nolock writeback, or to avoid merge new extents which was created by extents split. Update some related comments too. Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Baokun Li <libaokun1@huawei.com> Signed-off-by: Yang Erkun <yangerkun@huawei.com> Message-ID: <20251112084538.1658232-2-yangerkun@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-11-06ext4: make ext4_es_lookup_extent() pass out the extent seq counterZhang Yi
When querying extents in the extent status tree, we should hold the data_sem if we want to obtain the sequence number as a valid cookie simultaneously. However, currently, ext4_map_blocks() calls ext4_es_lookup_extent() without holding data_sem. Therefore, we should acquire i_es_lock instead, which also ensures that the sequence cookie and the extent remain consistent. Consequently, make ext4_es_lookup_extent() to pass out the sequence number when necessary. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Message-ID: <20251013015128.499308-4-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-07-31Merge tag 'ext4_for_linus_6.17-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "Major ext4 changes for 6.17: - Better scalability for ext4 block allocation - Fix insufficient credits when writing back large folios Miscellaneous bug fixes, especially when handling exteded attriutes, inline data, and fast commit" * tag 'ext4_for_linus_6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (39 commits) ext4: do not BUG when INLINE_DATA_FL lacks system.data xattr ext4: implement linear-like traversal across order xarrays ext4: refactor choose group to scan group ext4: convert free groups order lists to xarrays ext4: factor out ext4_mb_scan_group() ext4: factor out ext4_mb_might_prefetch() ext4: factor out __ext4_mb_scan_group() ext4: fix largest free orders lists corruption on mb_optimize_scan switch ext4: fix zombie groups in average fragment size lists ext4: merge freed extent with existing extents before insertion ext4: convert sbi->s_mb_free_pending to atomic_t ext4: fix typo in CR_GOAL_LEN_SLOW comment ext4: get rid of some obsolete EXT4_MB_HINT flags ext4: utilize multiple global goals to reduce contention ext4: remove unnecessary s_md_lock on update s_mb_last_group ext4: remove unnecessary s_mb_last_start ext4: separate stream goal hits from s_bal_goals for better tracking ext4: add ext4_try_lock_group() to skip busy groups ext4: initialize superblock fields in the kballoc-test.c kunit tests ext4: refactor the inline directory conversion and new directory codepaths ...
2025-07-13ext4: replace ext4_writepage_trans_blocks()Zhang Yi
After ext4 supports large folios, the semantics of reserving credits in pages is no longer applicable. In most scenarios, reserving credits in extents is sufficient. Therefore, introduce ext4_chunk_trans_extent() to replace ext4_writepage_trans_blocks(). move_extent_per_page() is the only remaining location where we are still processing extents in pages. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20250707140814.542883-10-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-06-23ext4: add FALLOC_FL_WRITE_ZEROES supportZhang Yi
Add support for FALLOC_FL_WRITE_ZEROES if the underlying device enable the unmap write zeroes operation. This first allocates blocks as unwritten, then issues a zero command outside of the running journal handle, and finally converts them to a written state. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://lore.kernel.org/20250619111806.3546162-10-yi.zhang@huaweicloud.com Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-05-20ext4: Add a WARN_ON_ONCE for querying LAST_IN_LEAF insteadRitesh Harjani (IBM)
We added the documentation in ext4_map_blocks() for usage of EXT4_GET_BLOCKS_QUERY_LAST_IN_LEAF flag. But It's better to add a WARN_ON_ONCE in case if anyone tries using this flag with CREATE to avoid a random issue later. Since depth can change with CREATE and it needs to be re-calculated before using it in there. Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/ee6e82a224c50b432df9ce1ce3333c50182d8473.1747677758.git.ritesh.list@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20ext4: Unwritten to written conversion requires EXT4_EX_NOCACHERitesh Harjani (IBM)
This fixes the atomic write patch series after it was rebased on top of extent status cache cleanup series i.e. 'commit 402e38e6b71f57 ("ext4: prevent stale extent cache entries caused by concurrent I/O writeback")' After the above series, EXT4_GET_BLOCKS_IO_CONVERT_EXT flag which has EXT4_GET_BLOCKS_IO_SUBMIT flag set, requires that the io submit context of any kind should pass EXT4_EX_NOCACHE to avoid caching unncecessary extents in the extent status cache. This patch fixes that by adding the EXT4_EX_NOCACHE flag in ext4_convert_unwritten_extents_atomic() for unwritten to written conversion calls to ext4_map_blocks(). Fixes: b86629c2b299 ("ext4: Add multi-fsblock atomic write support with bigalloc") Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/ea0ad9378ff6d31d73f4e53f87548e3a20817689.1747677758.git.ritesh.list@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20ext4: Add multi-fsblock atomic write support with bigallocRitesh Harjani (IBM)
EXT4 supports bigalloc feature which allows the FS to work in size of clusters (group of blocks) rather than individual blocks. This patch adds atomic write support for bigalloc so that systems with bs = ps can also create FS using - mkfs.ext4 -F -O bigalloc -b 4096 -C 16384 <dev> With bigalloc ext4 can support multi-fsblock atomic writes. We will have to adjust ext4's atomic write unit max value to cluster size. This can then support atomic write of size anywhere between [blocksize, clustersize]. This patch adds the required changes to enable multi-fsblock atomic write support using bigalloc in the next patch. In this patch for block allocation: we first query the underlying region of the requested range by calling ext4_map_blocks() call. Here are the various cases which we then handle depending upon the underlying mapping type: 1. If the underlying region for the entire requested range is a mapped extent, then we don't call ext4_map_blocks() to allocate anything. We don't need to even start the jbd2 txn in this case. 2. For an append write case, we create a mapped extent. 3. If the underlying region is entirely a hole, then we create an unwritten extent for the requested range. 4. If the underlying region is a large unwritten extent, then we split the extent into 2 unwritten extent of required size. 5. If the underlying region has any type of mixed mapping, then we call ext4_map_blocks() in a loop to zero out the unwritten and the hole regions within the requested range. This then provide a single mapped extent type mapping for the requested range. Note: We invoke ext4_map_blocks() in a loop with the EXT4_GET_BLOCKS_ZERO flag only when the underlying extent mapping of the requested range is not entirely a hole, an unwritten extent, or a fully mapped extent. That is, if the underlying region contains a mix of hole(s), unwritten extent(s), and mapped extent(s), we use this loop to ensure that all the short mappings are zeroed out. This guarantees that the entire requested range becomes a single, uniformly mapped extent. It is ok to do so because we know this is being done on a bigalloc enabled filesystem where the block bitmap represents the entire cluster unit. Note having a single contiguous underlying region of type mapped, unwrittn or hole is not a problem. But the reason to avoid writing on top of mixed mapping region is because, atomic writes requires all or nothing should get written for the userspace pwritev2 request. So if at any point in time during the write if a crash or a sudden poweroff occurs, the region undergoing atomic write should read either complete old data or complete new data. But it should never have a mix of both old and new data. So, we first convert any mixed mapping region to a single contiguous mapped extent before any data gets written to it. This is because normally FS will only convert unwritten extents to written at the end of the write in ->end_io() call. And if we allow the writes over a mixed mapping and if a sudden power off happens in between, we will end up reading mix of new data (over mapped extents) and old data (over unwritten extents), because unwritten to written conversion never went through. So to avoid this and to avoid writes getting torned due to mixed mapping, we first allocate a single contiguous block mapping and then do the write. Acked-by: Darrick J. Wong <djwong@kernel.org> Co-developed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Link: https://patch.msgid.link/c4965ac3407cbc773f0bc954d0966d9696f5038a.1747337952.git.ritesh.list@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20ext4: Add support for EXT4_GET_BLOCKS_QUERY_LEAF_BLOCKSRitesh Harjani (IBM)
There can be a case where there are contiguous extents on the adjacent leaf nodes of on-disk extent trees. So when someone tries to write to this contiguous range, ext4_map_blocks() call will split by returning 1 extent at a time if this is not already cached in extent_status tree cache (where if these extents when cached can get merged since they are contiguous). This is fine for a normal write however in case of atomic writes, it can't afford to break the write into two. Now this is also something that will only happen in the slow write case where we call ext4_map_blocks() for each of these extents spread across different leaf nodes. However, there is no guarantee that these extent status cache cannot be reclaimed before the last call to ext4_map_blocks() in ext4_map_blocks_atomic_write_slow(). Hence this patch adds support of EXT4_GET_BLOCKS_QUERY_LEAF_BLOCKS. This flag checks if the requested range can be fully found in extent status cache and return. If not, it looks up in on-disk extent tree via ext4_map_query_blocks(). If the found extent is the last entry in the leaf node, then it goes and queries the next lblk to see if there is an adjacent contiguous extent in the adjacent leaf node of the on-disk extent tree. Even though there can be a case where there are multiple adjacent extent entries spread across multiple leaf nodes. But we only read an adjacent leaf block i.e. in total of 2 extent entries spread across 2 leaf nodes. The reason for this is that we are mostly only going to support atomic writes with upto 64KB or maybe max upto 1MB of atomic write support. Acked-by: Darrick J. Wong <djwong@kernel.org> Co-developed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Link: https://patch.msgid.link/6bb563e661f5fbd80e266a9e6ce6e29178f555f6.1747337952.git.ritesh.list@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20ext4: remove sbi argument from ext4_chksum()Eric Biggers
Since ext4_chksum() no longer uses its sbi argument, remove it. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Link: https://patch.msgid.link/20250513053809.699974-2-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20ext4: correct the journal credits calculations of allocating blocksZhang Yi
The journal credits calculation in ext4_ext_index_trans_blocks() is currently inadequate. It only multiplies the depth of the extents tree and doesn't account for the blocks that may be required for adding the leaf extents themselves. After enabling large folios, we can easily run out of handle credits, triggering a warning in jbd2_journal_dirty_metadata() on filesystems with a 1KB block size. This occurs because we may need more extents when iterating through each large folio in ext4_do_writepages()->mpage_map_and_submit_extent(). Therefore, we should modify ext4_ext_index_trans_blocks() to include a count of the leaf extents in the worst case as well. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://patch.msgid.link/20250512063319.3539411-6-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20ext4: factor out ext4_get_maxbytes()Zhang Yi
There are several locations that get the correct maxbytes value based on the inode's block type. It would be beneficial to extract a common helper function to make the code more clear. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Baokun Li <libaokun1@huawei.com> Link: https://patch.msgid.link/20250506012009.3896990-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2025-05-20ext4: fix calculation of credits for extent tree modificationJan Kara
Luis and David are reporting that after running generic/750 test for 90+ hours on 2k ext4 filesystem, they are able to trigger a warning in jbd2_journal_dirty_metadata() complaining that there are not enough credits in the running transaction started in ext4_do_writepages(). Indeed the code in ext4_do_writepages() is racy and the extent tree can change between the time we compute credits necessary for extent tree computation and the time we actually modify the extent tree. Thus it may happen that the number of credits actually needed is higher. Modify ext4_ext_index_trans_blocks() to count with the worst case of maximum tree depth. This can reduce the possible number of writers that can operate in the system in parallel (because the credit estimates now won't fit in one transaction) but for reasonably sized journals this shouldn't really be an issue. So just go with a safe and simple fix. Link: https://lore.kernel.org/all/20250415013641.f2ppw6wov4kn4wq2@offworld Reported-by: Davidlohr Bueso <dave@stgolabs.net> Reported-by: Luis Chamberlain <mcgrof@kernel.org> Tested-by: kdevops@lists.linux.dev Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Link: https://patch.msgid.link/20250429175535.23125-2-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2025-05-15ext4: check env when mapping and modifying extentsZhang Yi
Add ext4_check_map_extents_env() to the places where loading extents, mapping blocks, removing blocks, and modifying extents, excluding the I/O writeback context. This function will verify whether the locking mechanisms in place are adequate. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://patch.msgid.link/20250423085257.122685-9-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-14ext4: prevent stale extent cache entries caused by concurrent get es_cacheZhang Yi
The EXT4_IOC_GET_ES_CACHE and EXT4_IOC_PRECACHE_EXTENTS currently invokes ext4_ext_precache() to preload the extent cache without holding the inode's i_rwsem. This can result in stale extent cache entries when competing with operations such as ext4_collapse_range() which calls ext4_ext_remove_space() or ext4_ext_shift_extents(). The problem arises when ext4_ext_remove_space() temporarily releases i_data_sem due to insufficient journal credits. During this interval, a concurrent EXT4_IOC_GET_ES_CACHE or EXT4_IOC_PRECACHE_EXTENTS may cache extent entries that are about to be deleted. As a result, these cached entries become stale and inconsistent with the actual extents. Loading the extents cache without holding the inode's i_rwsem or the mapping's invalidate_lock is not permitted besides during the writeback. Fix this by holding the i_rwsem during EXT4_IOC_GET_ES_CACHE and EXT4_IOC_PRECACHE_EXTENTS. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://patch.msgid.link/20250423085257.122685-6-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-14ext4: prevent stale extent cache entries caused by concurrent fiemapZhang Yi
The ext4_fiemap() currently invokes ext4_ext_precache() and iomap_fiemap() to preload the extent cache and query mapping information without holding the inode's i_rwsem. This can result in stale extent cache entries when competing with operations such as ext4_collapse_range() which calls ext4_ext_remove_space() or ext4_ext_shift_extents(). The problem arises when ext4_ext_remove_space() temporarily releases i_data_sem due to insufficient journal credits. During this interval, a concurrent ext4_fiemap() may cache extent entries that are about to be deleted. As a result, these cached entries become stale and inconsistent with the actual extents. Loading the extents cache without holding the inode's i_rwsem or the mapping's invalidate_lock is not permitted besides during the writeback. Fix this by holding the i_rwsem in ext4_fiemap(). Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://patch.msgid.link/20250423085257.122685-5-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-14ext4: prevent stale extent cache entries caused by concurrent I/O writebackZhang Yi
Currently, in the I/O writeback path, ext4_map_blocks() may attempt to cache additional unrelated extents in the extent status tree without holding the inode's i_rwsem and the mapping's invalidate_lock. This can lead to stale extent status entries remaining in certain scenarios, potentially causing data corruption. For example, when performing a collapse range in ext4_collapse_range(), it clears the extent cache and dirty pages before removing blocks and shifting extents. It also holds the i_data_sem during these two operations. However, both ext4_ext_remove_space() and ext4_ext_shift_extents() may briefly release the i_data_sem if journal credits are insufficient (ext4_datasem_ensure_credits()). If another writeback process writes dirty pages from other regions during this interval, it may cache extents that are about to be modified. Unless ext4_collapse_range() explicitly clears the extent cache again, these cached entries can become stale and inconsistent with the actual extents. 0 a n b c m | | | | | | [www][wwwwww][wwwwwwww]...[wwwww][wwww]... | | N M Assume that block a is dirty. The collapse range operation is removing data from n to m and drops i_data_sem immediately after removing the extent from b to c. At the same time, a concurrent writeback begins to write back block a; it will reloads the extent from [n, b) into the extent status tree since it does not hold the i_rwsem or the invalidate_lock. After the collapse range operation, it left the stale extent [n, b), which points logical block n to N, but the actual physical block of n should be M. Similarly, both ext4_insert_range() and ext4_truncate() have the same problem. ext4_punch_hole() survived since it re-add a hole extent entry after removing space since commit 9f1118223aa0 ("ext4: add a hole extent entry in cache after punch"). In most cases, during dirty page writeback, the block mapping information is likely to be found in the extent cache, making it less necessary to search for physical extents. Consequently, loading unrelated extent caches during writeback appears to be ineffective. Therefore, fix this by adds EXT4_EX_NOCACHE in the writeback path to prevent caching of unrelated extents, eliminating this potential source of corruption. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://patch.msgid.link/20250423085257.122685-4-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-14ext4: ext4: unify EXT4_EX_NOCACHE|NOFAIL flags in ext4_ext_remove_space()Zhang Yi
When removing space, we should use EXT4_EX_NOCACHE because we don't need to cache extents, and we should also use EXT4_EX_NOFAIL to prevent metadata inconsistencies that may arise from memory allocation failures. While ext4_ext_remove_space() already uses these two flags in most places, they are missing in ext4_ext_search_right() and read_extent_tree_block() calls. Unify the flags to ensure consistent behavior throughout the extent removal process. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Link: https://patch.msgid.link/20250423085257.122685-2-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-03-21ext4: correct the error handle in ext4_fallocate()Zhang Yi
The error out label of file_modified() should be out_inode_lock in ext4_fallocate(). Fixes: 2890e5e0f49e ("ext4: move out common parts into ext4_fallocate()") Reported-by: Baokun Li <libaokun1@huawei.com> Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Baokun Li <libaokun1@huawei.com> Link: https://patch.msgid.link/20250319023557.2785018-1-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-03-17ext4: remove redundant function ext4_has_metadata_csumEric Biggers
Since commit f2b4fa19647e ("ext4: switch to using the crc32c library"), ext4_has_metadata_csum() is just an alias for ext4_has_feature_metadata_csum(). ext4_has_feature_metadata_csum() is generated by EXT4_FEATURE_RO_COMPAT_FUNCS and uses the regular naming convention for checking a single ext4 feature. Therefore, remove ext4_has_metadata_csum() and update all its callers to use ext4_has_feature_metadata_csum() directly. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Link: https://patch.msgid.link/20250207031335.42637-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-02-10ext4: move out common parts into ext4_fallocate()Zhang Yi
Currently, all zeroing ranges, punch holes, collapse ranges, and insert ranges first wait for all existing direct I/O workers to complete, and then they acquire the mapping's invalidate lock before performing the actual work. These common components are nearly identical, so we can simplify the code by factoring them out into the ext4_fallocate(). Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20241220011637.1157197-11-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-02-10ext4: move out inode_lock into ext4_fallocate()Zhang Yi
Currently, all five sub-functions of ext4_fallocate() acquire the inode's i_rwsem at the beginning and release it before exiting. This process can be simplified by factoring out the management of i_rwsem into the ext4_fallocate() function. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20241220011637.1157197-10-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-02-10ext4: factor out ext4_do_fallocate()Zhang Yi
Now the real job of normal fallocate are open coded in ext4_fallocate(), factor out a new helper ext4_do_fallocate() to do the real job, like others functions (e.g. ext4_zero_range()) in ext4_fallocate() do, this can make the code more clear, no functional changes. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20241220011637.1157197-9-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-02-10ext4: refactor ext4_insert_range()Zhang Yi
Simplify ext4_insert_range() and align its code style with that of ext4_collapse_range(). Refactor it by: a) renaming variables, b) removing redundant input parameter checks and moving the remaining checks under i_rwsem in preparation for future refactoring, and c) renaming the three stale error tags. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20241220011637.1157197-8-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-02-10ext4: refactor ext4_collapse_range()Zhang Yi
Simplify ext4_collapse_range() and align its code style with that of ext4_zero_range() and ext4_punch_hole(). Refactor it by: a) renaming variables, b) removing redundant input parameter checks and moving the remaining checks under i_rwsem in preparation for future refactoring, and c) renaming the three stale error tags. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20241220011637.1157197-7-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-02-10ext4: refactor ext4_zero_range()Zhang Yi
The current implementation of ext4_zero_range() contains complex position calculations and stale error tags. To improve the code's clarity and maintainability, it is essential to clean up the code and improve its readability, this can be achieved by: a) simplifying and renaming variables, making the style the same as ext4_punch_hole(); b) eliminating unnecessary position calculations, writing back all data in data=journal mode, and drop page cache from the original offset to the end, rather than using aligned blocks; c) renaming the stale out_mutex tags. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20241220011637.1157197-6-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-02-10ext4: don't explicit update times in ext4_fallocate()Zhang Yi
After commit 'ad5cd4f4ee4d ("ext4: fix fallocate to use file_modified to update permissions consistently"), we can update mtime and ctime appropriately through file_modified() when doing zero range, collapse rage, insert range and punch hole, hence there is no need to explicit update times in those paths, just drop them. Signed-off-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Link: https://patch.msgid.link/20241220011637.1157197-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>