kernel/linux.git/fs/exfat/inode.c, branch linux-7.1.y

Merge tag 'exfat-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat

2026-04-13T23:57:31+00:00

Pull exfat updates from Namjae Jeon: - Implement FALLOC_FL_ALLOCATE_RANGE to add support for preallocating clusters without zeroing, helping to reduce file fragmentation - Add a unified block readahead helper for FAT chain conversion, bitmap allocation, and directory entry lookups - Optimize exfat_chain_cont_cluster() by caching buffer heads to minimize mark_buffer_dirty() and mirroring overhead during NO_FAT_CHAIN to FAT_CHAIN conversion - Switch to truncate_inode_pages_final() in evict_inode() to prevent BUG_ON caused by shadow entries during reclaim - Fix a 32-bit truncation bug in directory entry calculations by ensuring proper bitwise coercion - Fix sb->s_maxbytes calculation to correctly reflect the maximum possible volume size for a given cluster size, resolving xfstests generic/213 - Introduced exfat_cluster_walk() helper to traverse FAT chains by a specified step, handling both ALLOC_NO_FAT_CHAIN and ALLOC_FAT_CHAIN modes - Introduced exfat_chain_advance() helper to advance an exfat_chain structure, updating both the current cluster and remaining size - Remove dead assignments and fix Smatch warnings * tag 'exfat-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat: exfat: use exfat_chain_advance helper exfat: introduce exfat_chain_advance helper exfat: remove NULL cache pointer case in exfat_ent_get exfat: use exfat_cluster_walk helper exfat: introduce exfat_cluster_walk helper exfat: fix incorrect directory checksum after rename to shorter name exfat: fix s_maxbytes exfat: fix passing zero to ERR_PTR() in exfat_mkdir() exfat: fix error handling for FAT table operations exfat: optimize exfat_chain_cont_cluster with cached buffer heads exfat: drop redundant sec parameter from exfat_mirror_bh exfat: use readahead helper in exfat_get_dentry exfat: use readahead helper in exfat_allocate_bitmap exfat: add block readahead in exfat_chain_cont_cluster exfat: add fallocate FALLOC_FL_ALLOCATE_RANGE support exfat: Fix bitwise operation having different size exfat: Drop dead assignment of num_clusters exfat: use truncate_inode_pages_final() at evict_inode()

exfat: use exfat_cluster_walk helper

2026-04-03T13:41:05+00:00

Replace the custom exfat_walk_fat_chain() function and open-coded FAT chain walking logic with the exfat_cluster_walk() helper across exfat_find_location, __exfat_get_dentry_set, and exfat_map_cluster. Suggested-by: Sungjong Seo Signed-off-by: Chi Zhiling Reviewed-by: Sungjong Seo Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: Drop pointless invalidate_inode_buffers() call

2026-03-26T14:03:27+00:00

EXFAT never calls mark_buffer_dirty_inode() and thus invalidate_inode_buffers() never has anything to evict. Drop the pointless call. Signed-off-by: Jan Kara Link: https://patch.msgid.link/20260326095354.16340-49-jack@suse.cz Signed-off-by: Christian Brauner

exfat: fix error handling for FAT table operations

2026-03-05T12:09:35+00:00

Fix three error handling issues in FAT table operations: 1. Fix exfat_update_bh() to properly return errors from sync_dirty_buffer 2. Fix exfat_end_bh() to properly return errors from exfat_update_bh() and exfat_mirror_bh() 3. Fix ignored return values from exfat_chain_cont_cluster() in inode.c and namei.c These fixes ensure that FAT table write errors are properly propagated to the caller instead of being silently ignored. Signed-off-by: Chi Zhiling Signed-off-by: Namjae Jeon

exfat: Drop dead assignment of num_clusters

2026-03-04T10:22:41+00:00

num_clusters is not used anywhere afterwards. Remove assignment. Found by static code analysis using Klocwork. Signed-off-by: Philipp Hahn Signed-off-by: Namjae Jeon

exfat: use truncate_inode_pages_final() at evict_inode()

2026-02-26T09:33:50+00:00

Currently, exfat uses truncate_inode_pages() in exfat_evict_inode(). However, truncate_inode_pages() does not mark the mapping as exiting, so reclaim may still install shadow entries for the mapping until the inode teardown completes. In older kernels like Linux 5.10, if shadow entries are present at that point,clear_inode() can hit BUG_ON(inode->i_data.nrexceptional); To align with VFS eviction semantics and prevent this situation, switch to truncate_inode_pages_final() in ->evict_inode(). Other filesystems were updated to use truncate_inode_pages_final() in ->evict_inode() by commit 91b0abe36a7b ("mm + fs: store shadow entries in page cache")'. Signed-off-by: Yang Wen Signed-off-by: Namjae Jeon

exfat: remove unnecessary else after return statement

2026-02-12T12:21:51+00:00

Else-branch is unnecessary after return statement in if-branch. Remove to enhance readability and reduce indentation. Signed-off-by: William Hansen-Baird Signed-off-by: Namjae Jeon

exfat: support multi-cluster for exfat_get_cluster

2026-02-12T12:21:51+00:00

This patch introduces a count parameter to exfat_get_cluster, which serves as an input parameter for the caller to specify the desired number of clusters, and as an output parameter to store the length of consecutive clusters. This patch can improve read performance by reducing the number of get_block calls in sequential read scenarios. speacially in small cluster size. According to my test data, the performance improvement is approximately 10% when read FAT_CHAIN file with 512 bytes of cluster size. 454 MB/s -> 511 MB/s Suggested-by: Yuezhang Mo Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: support multi-cluster for exfat_map_cluster

2026-02-12T12:21:50+00:00

This patch introduces a parameter 'count' to support fetching multiple clusters in exfat_map_cluster. The returned 'count' indicates the number of consecutive clusters, or 0 when the input cluster offset is past EOF. And the 'count' is also an input parameter for the caller to specify the required number of clusters. Only NO_FAT_CHAIN files enable multi-cluster fetching in this patch. After this patch, the time proportion of exfat_get_block has decreased, The performance data is as follows: Cluster size: 512 bytes Sequential read of a 30GB NO_FAT_CHAIN file: 2.4GB/s -> 2.5 GB/s proportion of exfat_get_block: 10.8% -> 0.02% Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: remove handling of non-file types in exfat_map_cluster

2026-02-12T12:21:50+00:00

Yuezhang said: "exfat_map_cluster() is only used for files. The code in this 'else' block is never executed and can be cleaned up." Suggested-by: Yuezhang Mo Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon