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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /fs/exfat/cache.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'fs/exfat/cache.c')
| -rw-r--r-- | fs/exfat/cache.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/fs/exfat/cache.c b/fs/exfat/cache.c new file mode 100644 index 000000000..7c8b4182f --- /dev/null +++ b/fs/exfat/cache.c @@ -0,0 +1,357 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * linux/fs/fat/cache.c + * + * Written 1992,1993 by Werner Almesberger + * + * Mar 1999. AV. Changed cache, so that it uses the starting cluster instead + * of inode number. + * May 1999. AV. Fixed the bogosity with FAT32 (read "FAT28"). Fscking lusers. + * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. + */ + +#include <linux/slab.h> +#include <linux/unaligned.h> +#include <linux/buffer_head.h> + +#include "exfat_raw.h" +#include "exfat_fs.h" + +#define EXFAT_MAX_CACHE 16 + +struct exfat_cache { + struct list_head cache_list; + unsigned int nr_contig; /* number of contiguous clusters */ + unsigned int fcluster; /* cluster number in the file. */ + unsigned int dcluster; /* cluster number on disk. */ +}; + +struct exfat_cache_id { + unsigned int id; + unsigned int nr_contig; + unsigned int fcluster; + unsigned int dcluster; +}; + +static struct kmem_cache *exfat_cachep; + +static void exfat_cache_init_once(void *c) +{ + struct exfat_cache *cache = (struct exfat_cache *)c; + + INIT_LIST_HEAD(&cache->cache_list); +} + +int exfat_cache_init(void) +{ + exfat_cachep = kmem_cache_create("exfat_cache", + sizeof(struct exfat_cache), + 0, SLAB_RECLAIM_ACCOUNT, + exfat_cache_init_once); + if (!exfat_cachep) + return -ENOMEM; + return 0; +} + +void exfat_cache_shutdown(void) +{ + if (!exfat_cachep) + return; + kmem_cache_destroy(exfat_cachep); +} + +static inline struct exfat_cache *exfat_cache_alloc(void) +{ + return kmem_cache_alloc(exfat_cachep, GFP_NOFS); +} + +static inline void exfat_cache_free(struct exfat_cache *cache) +{ + WARN_ON(!list_empty(&cache->cache_list)); + kmem_cache_free(exfat_cachep, cache); +} + +static inline void exfat_cache_update_lru(struct inode *inode, + struct exfat_cache *cache) +{ + struct exfat_inode_info *ei = EXFAT_I(inode); + + if (ei->cache_lru.next != &cache->cache_list) + list_move(&cache->cache_list, &ei->cache_lru); +} + +/* + * Find the cache that covers or precedes 'fclus' and return the last + * cluster before the next cache range. + */ +static inline unsigned int +exfat_cache_lookup(struct inode *inode, struct exfat_cache_id *cid, + unsigned int fclus, unsigned int end, + unsigned int *cached_fclus, unsigned int *cached_dclus) +{ + struct exfat_inode_info *ei = EXFAT_I(inode); + static struct exfat_cache nohit = { .fcluster = 0, }; + struct exfat_cache *hit = &nohit, *p; + unsigned int tail = 0; /* End boundary of hit cache */ + + /* + * Search range [fclus, end]. Stop early if: + * 1. Cache covers entire range, or + * 2. Next cache starts at current cache tail + */ + spin_lock(&ei->cache_lru_lock); + list_for_each_entry(p, &ei->cache_lru, cache_list) { + /* Find the cache of "fclus" or nearest cache. */ + if (p->fcluster <= fclus) { + if (p->fcluster < hit->fcluster) + continue; + + hit = p; + tail = hit->fcluster + hit->nr_contig; + + /* Current cache covers [fclus, end] completely */ + if (tail >= end) + break; + } else if (p->fcluster <= end) { + end = p->fcluster - 1; + + /* + * If we have a hit and next cache starts within/at + * its tail, caches are contiguous, stop searching. + */ + if (tail && tail >= end) + break; + } + } + if (hit != &nohit) { + unsigned int offset; + + exfat_cache_update_lru(inode, hit); + cid->id = ei->cache_valid_id; + cid->nr_contig = hit->nr_contig; + cid->fcluster = hit->fcluster; + cid->dcluster = hit->dcluster; + + offset = min(cid->nr_contig, fclus - cid->fcluster); + *cached_fclus = cid->fcluster + offset; + *cached_dclus = cid->dcluster + offset; + } + spin_unlock(&ei->cache_lru_lock); + + /* Return next cache start or 'end' if no more caches */ + return end; +} + +static struct exfat_cache *exfat_cache_merge(struct inode *inode, + struct exfat_cache_id *new) +{ + struct exfat_inode_info *ei = EXFAT_I(inode); + struct exfat_cache *p; + + list_for_each_entry(p, &ei->cache_lru, cache_list) { + /* Find the same part as "new" in cluster-chain. */ + if (p->fcluster == new->fcluster) { + if (new->nr_contig > p->nr_contig) + p->nr_contig = new->nr_contig; + return p; + } + } + return NULL; +} + +static void exfat_cache_add(struct inode *inode, + struct exfat_cache_id *new) +{ + struct exfat_inode_info *ei = EXFAT_I(inode); + struct exfat_cache *cache, *tmp; + + if (new->fcluster == EXFAT_EOF_CLUSTER) /* dummy cache */ + return; + + spin_lock(&ei->cache_lru_lock); + if (new->id != EXFAT_CACHE_VALID && + new->id != ei->cache_valid_id) + goto unlock; /* this cache was invalidated */ + + cache = exfat_cache_merge(inode, new); + if (cache == NULL) { + if (ei->nr_caches < EXFAT_MAX_CACHE) { + ei->nr_caches++; + spin_unlock(&ei->cache_lru_lock); + + tmp = exfat_cache_alloc(); + if (!tmp) { + spin_lock(&ei->cache_lru_lock); + ei->nr_caches--; + spin_unlock(&ei->cache_lru_lock); + return; + } + + spin_lock(&ei->cache_lru_lock); + cache = exfat_cache_merge(inode, new); + if (cache != NULL) { + ei->nr_caches--; + exfat_cache_free(tmp); + goto out_update_lru; + } + cache = tmp; + } else { + struct list_head *p = ei->cache_lru.prev; + + cache = list_entry(p, + struct exfat_cache, cache_list); + } + cache->fcluster = new->fcluster; + cache->dcluster = new->dcluster; + cache->nr_contig = new->nr_contig; + } +out_update_lru: + exfat_cache_update_lru(inode, cache); +unlock: + spin_unlock(&ei->cache_lru_lock); +} + +/* + * Cache invalidation occurs rarely, thus the LRU chain is not updated. It + * fixes itself after a while. + */ +static void __exfat_cache_inval_inode(struct inode *inode) +{ + struct exfat_inode_info *ei = EXFAT_I(inode); + struct exfat_cache *cache; + + while (!list_empty(&ei->cache_lru)) { + cache = list_entry(ei->cache_lru.next, + struct exfat_cache, cache_list); + list_del_init(&cache->cache_list); + ei->nr_caches--; + exfat_cache_free(cache); + } + /* Update. The copy of caches before this id is discarded. */ + ei->cache_valid_id++; + if (ei->cache_valid_id == EXFAT_CACHE_VALID) + ei->cache_valid_id++; +} + +void exfat_cache_inval_inode(struct inode *inode) +{ + struct exfat_inode_info *ei = EXFAT_I(inode); + + spin_lock(&ei->cache_lru_lock); + __exfat_cache_inval_inode(inode); + spin_unlock(&ei->cache_lru_lock); +} + +static inline int cache_contiguous(struct exfat_cache_id *cid, + unsigned int dclus) +{ + cid->nr_contig++; + return cid->dcluster + cid->nr_contig == dclus; +} + +static inline void cache_init(struct exfat_cache_id *cid, + unsigned int fclus, unsigned int dclus) +{ + cid->id = EXFAT_CACHE_VALID; + cid->fcluster = fclus; + cid->dcluster = dclus; + cid->nr_contig = 0; +} + +int exfat_get_cluster(struct inode *inode, unsigned int cluster, + unsigned int *dclus, unsigned int *count, + unsigned int *last_dclus) +{ + struct super_block *sb = inode->i_sb; + struct exfat_inode_info *ei = EXFAT_I(inode); + struct buffer_head *bh = NULL; + struct exfat_cache_id cid; + unsigned int content, fclus; + unsigned int end = cluster + *count - 1; + + if (ei->start_clu == EXFAT_FREE_CLUSTER) { + exfat_fs_error(sb, + "invalid access to exfat cache (entry 0x%08x)", + ei->start_clu); + return -EIO; + } + + fclus = 0; + *dclus = ei->start_clu; + *last_dclus = *dclus; + + /* + * This case should not exist, as exfat_map_cluster function doesn't + * call this routine when start_clu == EXFAT_EOF_CLUSTER. + * This case is retained here for routine completeness. + */ + if (*dclus == EXFAT_EOF_CLUSTER) { + *count = 0; + return 0; + } + + /* If only the first cluster is needed, return now. */ + if (fclus == cluster && *count == 1) + return 0; + + cache_init(&cid, fclus, *dclus); + /* + * Update the 'end' to exclude the next cache range, as clusters in + * different cache are typically not contiguous. + */ + end = exfat_cache_lookup(inode, &cid, cluster, end, &fclus, dclus); + + /* Return if the cache covers the entire range. */ + if (cid.fcluster + cid.nr_contig >= end) { + *count = end - cluster + 1; + return 0; + } + + /* Find the first cluster we need. */ + while (fclus < cluster) { + if (exfat_ent_get(sb, *dclus, &content, &bh)) + return -EIO; + + *last_dclus = *dclus; + *dclus = content; + fclus++; + + if (content == EXFAT_EOF_CLUSTER) + break; + + if (!cache_contiguous(&cid, *dclus)) + cache_init(&cid, fclus, *dclus); + } + + /* + * Now the cid cache contains the first cluster requested, collect + * the remaining clusters of this contiguous extent. + */ + if (*dclus != EXFAT_EOF_CLUSTER) { + unsigned int clu = *dclus; + + while (fclus < end) { + if (exfat_ent_get(sb, clu, &content, &bh)) + return -EIO; + if (++clu != content) + break; + fclus++; + } + cid.nr_contig = fclus - cid.fcluster; + *count = fclus - cluster + 1; + + /* + * Cache this discontiguous cluster, we'll definitely need + * it later + */ + if (fclus < end && content != EXFAT_EOF_CLUSTER) { + exfat_cache_add(inode, &cid); + cache_init(&cid, fclus + 1, content); + } + } else { + *count = 0; + } + brelse(bh); + exfat_cache_add(inode, &cid); + return 0; +} |
