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path: root/fs/exfat/cache.c
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2026-02-12exfat: support multi-cluster for exfat_get_clusterChi Zhiling
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 <Yuezhang.Mo@sony.com> Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-02-12exfat: return the start of next cache in exfat_cache_lookupChi Zhiling
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 <chizhiling@kylinos.cn> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-02-12exfat: tweak cluster cache to support zero offsetChi Zhiling
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 <chizhiling@kylinos.cn> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-02-12exfat: reuse cache to improve exfat_get_clusterChi Zhiling
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 <chizhiling@kylinos.cn> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-02-12exfat: reduce the number of parameters for exfat_get_cluster()Chi Zhiling
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 <chizhiling@kylinos.cn> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-02-12exfat: remove the unreachable warning for cache miss casesChi Zhiling
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 <chizhiling@kylinos.cn> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-02-12exfat: remove the check for infinite cluster chain loopChi Zhiling
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 <chizhiling@kylinos.cn> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-02-12exfat: support reuse buffer head for exfat_ent_getChi Zhiling
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 <chizhiling@kylinos.cn> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2024-10-02move asm/unaligned.h to linux/unaligned.hAl Viro
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
2024-03-12mm, slab: remove last vestiges of SLAB_MEM_SPREADLinus Torvalds
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 <torvalds@linux-foundation.org>
2020-10-07exfat: fix use of uninitialized spinlock on error pathNamjae Jeon
syzbot reported warning message: Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d6/0x29e lib/dump_stack.c:118 register_lock_class+0xf06/0x1520 kernel/locking/lockdep.c:893 __lock_acquire+0xfd/0x2ae0 kernel/locking/lockdep.c:4320 lock_acquire+0x148/0x720 kernel/locking/lockdep.c:5029 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] exfat_cache_inval_inode+0x30/0x280 fs/exfat/cache.c:226 exfat_evict_inode+0x124/0x270 fs/exfat/inode.c:660 evict+0x2bb/0x6d0 fs/inode.c:576 exfat_fill_super+0x1e07/0x27d0 fs/exfat/super.c:681 get_tree_bdev+0x3e9/0x5f0 fs/super.c:1342 vfs_get_tree+0x88/0x270 fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline] path_mount+0x179d/0x29e0 fs/namespace.c:3192 do_mount fs/namespace.c:3205 [inline] __do_sys_mount fs/namespace.c:3413 [inline] __se_sys_mount+0x126/0x180 fs/namespace.c:3390 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 If exfat_read_root() returns an error, spinlock is used in exfat_evict_inode() without initialization. This patch combines exfat_cache_init_inode() with exfat_inode_init_once() to initialize spinlock by slab constructor. Fixes: c35b6810c495 ("exfat: add exfat cache") Cc: stable@vger.kernel.org # v5.7+ Reported-by: syzbot <syzbot+b91107320911a26c9a95@syzkaller.appspotmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
2020-03-05exfat: add exfat cacheNamjae Jeon
This adds the implementation of exfat cache. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Reviewed-by: Pali Rohár <pali.rohar@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>