kernel/linux.git/fs/exfat/cache.c, branch v7.0-rc7

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: return the start of next cache in exfat_cache_lookup

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

Change exfat_cache_lookup to return the cluster number of the last cluster before the next cache (i.e., the end of the current cache range) or the given 'end' if there is no next cache. This allows the caller to know whether the next cluster after the current cache is cached. The function signature is changed to accept an 'end' parameter, which is the upper bound of the search range. The function now stops early if it finds a cache that starts within the current cache's tail, meaning caches are contiguous. The return value is the cluster number at which the next cache starts (minus one) or the original 'end' if no next cache is found. The new behavior is illustrated as follows: cache: [ccccccc-------ccccccccc] search: [..................] return: ^ Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: tweak cluster cache to support zero offset

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

The current cache mechanism does not support reading clusters starting from a file offset of zero. This patch enables that feature in preparation for subsequent reads of contiguous clusters from offset zero. 1. support finding clusters with zero offset. 2. allow clusters with zero offset to be cached. Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: reuse cache to improve exfat_get_cluster

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

Since exfat_ent_get supports cache buffer head, we can use this option to reduce sb_bread calls when fetching consecutive entries. Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: reduce the number of parameters for exfat_get_cluster()

2026-02-12T12:21:49+00:00

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: remove the unreachable warning for cache miss cases

2026-02-12T12:21:49+00:00

The cache_id remains unchanged on a cache miss; its value is always exactly what was set by cache_init. Therefore, checking this value again is meaningless. Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: remove the check for infinite cluster chain loop

2026-02-12T12:21:49+00:00

The infinite cluster chain loop check is not work because the loop will terminate when fclus reaches the parameter cluster, and the parameter cluster value is never greater than ei->valid_size. The following relationship holds: 'fclus' < 'cluster' ≤ ei->valid_size ≤ sb->num_clusters The check would only be triggered if a cluster number greater than sb->num_clusters is passed, but no caller currently does this. Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

exfat: support reuse buffer head for exfat_ent_get

2026-02-12T12:21:48+00:00

This patch is part 2 of cached buffer head for exfat_ent_get, it introduces an argument for exfat_ent_get, and make sure this routine releases buffer head refcount when any error return. Signed-off-by: Chi Zhiling Reviewed-by: Yuezhang Mo Signed-off-by: Namjae Jeon

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23+00:00

asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

mm, slab: remove last vestiges of SLAB_MEM_SPREAD

2024-03-13T03:32:19+00:00

Yes, yes, I know the slab people were planning on going slow and letting every subsystem fight this thing on their own. But let's just rip off the band-aid and get it over and done with. I don't want to see a number of unnecessary pull requests just to get rid of a flag that no longer has any meaning. This was mainly done with a couple of 'sed' scripts and then some manual cleanup of the end result. Link: https://lore.kernel.org/all/CAHk-=wji0u+OOtmAOD-5JV3SXcRJF___k_+8XNKmak0yd5vW1Q@mail.gmail.com/ Signed-off-by: Linus Torvalds