kernel.git/fs/exfat/inode.c, branch master

exfat: remove unnecessary else after return statement

2026-02-12T12:21:51Z

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

2026-02-12T12:21:51Z

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

2026-02-12T12:21:50Z

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

2026-02-12T12:21:50Z

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

exfat: reduce the number of parameters for exfat_get_cluster()

2026-02-12T12:21:49Z

Remove parameter 'fclus' and 'allow_eof': - The fclus parameter is changed to a local variable as it is not needed to be returned. - The passed allow_eof parameter was always 1, remove it and the associated error handling. Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: drop redundant conversion to bool

2025-09-30T04:34:43Z

The result of integer comparison already evaluates to bool. No need for explicit conversion. No functional impact. Signed-off-by: Xichao Zhao Signed-off-by: Namjae Jeon

fs: change write_begin/write_end interface to take struct kiocb *

2025-07-16T12:48:18Z

Change the address_space_operations callbacks write_begin() and write_end() to take struct kiocb * as the first argument instead of struct file *. Update all affected function prototypes, implementations, call sites, and related documentation across VFS, filesystems, and block layer. Part of a series refactoring address_space_operations write_begin and write_end callbacks to use struct kiocb for passing write context and flags. Signed-off-by: Taotao Chen Link: https://lore.kernel.org/20250716093559.217344-4-chentaotao@didiglobal.com Signed-off-by: Christian Brauner

exfat: call bh_read in get_block only when necessary

2025-03-29T13:03:11Z

With commit 11a347fb6cef ("exfat: change to get file size from DataLength"), exfat_get_block() can now handle valid_size. However, most partial unwritten blocks that could be mapped with other blocks are being inefficiently processed separately as individual blocks. Except for partial unwritten blocks that require independent processing, let's handle them simply as before. Signed-off-by: Sungjong Seo Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: fix potential wrong error return from get_block

2025-03-29T13:03:07Z

If there is no error, get_block() should return 0. However, when bh_read() returns 1, get_block() also returns 1 in the same manner. Let's set err to 0, if there is no error from bh_read() Fixes: 11a347fb6cef ("exfat: change to get file size from DataLength") Cc: stable@vger.kernel.org Signed-off-by: Sungjong Seo Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: fix random stack corruption after get_block

2025-03-27T12:18:02Z

When get_block is called with a buffer_head allocated on the stack, such as do_mpage_readpage, stack corruption due to buffer_head UAF may occur in the following race condition situation. mpage_read_folio <> do_mpage_readpage exfat_get_block bh_read __bh_read get_bh(bh) submit_bh wait_on_buffer ... end_buffer_read_sync __end_buffer_read_notouch unlock_buffer <> ... ... ... ... <> . . another_function <> put_bh(bh) atomic_dec(bh->b_count) * stack corruption here * This patch returns -EAGAIN if a folio does not have buffers when bh_read needs to be called. By doing this, the caller can fallback to functions like block_read_full_folio(), create a buffer_head in the folio, and then call get_block again. Let's do not call bh_read() with on-stack buffer_head. Fixes: 11a347fb6cef ("exfat: change to get file size from DataLength") Cc: stable@vger.kernel.org Tested-by: Yeongjin Gil Signed-off-by: Sungjong Seo Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon