From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux 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 ... --- fs/fat/cache.c | 381 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 381 insertions(+) create mode 100644 fs/fat/cache.c (limited to 'fs/fat/cache.c') diff --git a/fs/fat/cache.c b/fs/fat/cache.c new file mode 100644 index 000000000..1b87354e2 --- /dev/null +++ b/fs/fat/cache.c @@ -0,0 +1,381 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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. + */ + +#include +#include "fat.h" + +/* this must be > 0. */ +#define FAT_MAX_CACHE 8 + +struct fat_cache { + struct list_head cache_list; + int nr_contig; /* number of contiguous clusters */ + int fcluster; /* cluster number in the file. */ + int dcluster; /* cluster number on disk. */ +}; + +struct fat_cache_id { + unsigned int id; + int nr_contig; + int fcluster; + int dcluster; +}; + +static struct kmem_cache *fat_cache_cachep; + +static void init_once(void *foo) +{ + struct fat_cache *cache = (struct fat_cache *)foo; + + INIT_LIST_HEAD(&cache->cache_list); +} + +int __init fat_cache_init(void) +{ + fat_cache_cachep = kmem_cache_create("fat_cache", + sizeof(struct fat_cache), + 0, SLAB_RECLAIM_ACCOUNT, + init_once); + if (fat_cache_cachep == NULL) + return -ENOMEM; + return 0; +} + +void fat_cache_destroy(void) +{ + kmem_cache_destroy(fat_cache_cachep); +} + +static inline struct fat_cache *fat_cache_alloc(void) +{ + return kmem_cache_alloc(fat_cache_cachep, GFP_NOFS); +} + +static inline void fat_cache_free(struct fat_cache *cache) +{ + BUG_ON(!list_empty(&cache->cache_list)); + kmem_cache_free(fat_cache_cachep, cache); +} + +static inline void fat_cache_update_lru(struct inode *inode, + struct fat_cache *cache) +{ + if (MSDOS_I(inode)->cache_lru.next != &cache->cache_list) + list_move(&cache->cache_list, &MSDOS_I(inode)->cache_lru); +} + +static int fat_cache_lookup(struct inode *inode, int fclus, + struct fat_cache_id *cid, + int *cached_fclus, int *cached_dclus) +{ + static struct fat_cache nohit = { .fcluster = 0, }; + + struct fat_cache *hit = &nohit, *p; + int offset = -1; + + spin_lock(&MSDOS_I(inode)->cache_lru_lock); + list_for_each_entry(p, &MSDOS_I(inode)->cache_lru, cache_list) { + /* Find the cache of "fclus" or nearest cache. */ + if (p->fcluster <= fclus && hit->fcluster < p->fcluster) { + hit = p; + if ((hit->fcluster + hit->nr_contig) < fclus) { + offset = hit->nr_contig; + } else { + offset = fclus - hit->fcluster; + break; + } + } + } + if (hit != &nohit) { + fat_cache_update_lru(inode, hit); + + cid->id = MSDOS_I(inode)->cache_valid_id; + cid->nr_contig = hit->nr_contig; + cid->fcluster = hit->fcluster; + cid->dcluster = hit->dcluster; + *cached_fclus = cid->fcluster + offset; + *cached_dclus = cid->dcluster + offset; + } + spin_unlock(&MSDOS_I(inode)->cache_lru_lock); + + return offset; +} + +static struct fat_cache *fat_cache_merge(struct inode *inode, + struct fat_cache_id *new) +{ + struct fat_cache *p; + + list_for_each_entry(p, &MSDOS_I(inode)->cache_lru, cache_list) { + /* Find the same part as "new" in cluster-chain. */ + if (p->fcluster == new->fcluster) { + BUG_ON(p->dcluster != new->dcluster); + if (new->nr_contig > p->nr_contig) + p->nr_contig = new->nr_contig; + return p; + } + } + return NULL; +} + +static void fat_cache_add(struct inode *inode, struct fat_cache_id *new) +{ + struct fat_cache *cache, *tmp; + + if (new->fcluster == -1) /* dummy cache */ + return; + + spin_lock(&MSDOS_I(inode)->cache_lru_lock); + if (new->id != FAT_CACHE_VALID && + new->id != MSDOS_I(inode)->cache_valid_id) + goto out; /* this cache was invalidated */ + + cache = fat_cache_merge(inode, new); + if (cache == NULL) { + if (MSDOS_I(inode)->nr_caches < FAT_MAX_CACHE) { + MSDOS_I(inode)->nr_caches++; + spin_unlock(&MSDOS_I(inode)->cache_lru_lock); + + tmp = fat_cache_alloc(); + if (!tmp) { + spin_lock(&MSDOS_I(inode)->cache_lru_lock); + MSDOS_I(inode)->nr_caches--; + spin_unlock(&MSDOS_I(inode)->cache_lru_lock); + return; + } + + spin_lock(&MSDOS_I(inode)->cache_lru_lock); + cache = fat_cache_merge(inode, new); + if (cache != NULL) { + MSDOS_I(inode)->nr_caches--; + fat_cache_free(tmp); + goto out_update_lru; + } + cache = tmp; + } else { + struct list_head *p = MSDOS_I(inode)->cache_lru.prev; + cache = list_entry(p, struct fat_cache, cache_list); + } + cache->fcluster = new->fcluster; + cache->dcluster = new->dcluster; + cache->nr_contig = new->nr_contig; + } +out_update_lru: + fat_cache_update_lru(inode, cache); +out: + spin_unlock(&MSDOS_I(inode)->cache_lru_lock); +} + +/* + * Cache invalidation occurs rarely, thus the LRU chain is not updated. It + * fixes itself after a while. + */ +static void __fat_cache_inval_inode(struct inode *inode) +{ + struct msdos_inode_info *i = MSDOS_I(inode); + struct fat_cache *cache; + + while (!list_empty(&i->cache_lru)) { + cache = list_entry(i->cache_lru.next, + struct fat_cache, cache_list); + list_del_init(&cache->cache_list); + i->nr_caches--; + fat_cache_free(cache); + } + /* Update. The copy of caches before this id is discarded. */ + i->cache_valid_id++; + if (i->cache_valid_id == FAT_CACHE_VALID) + i->cache_valid_id++; +} + +void fat_cache_inval_inode(struct inode *inode) +{ + spin_lock(&MSDOS_I(inode)->cache_lru_lock); + __fat_cache_inval_inode(inode); + spin_unlock(&MSDOS_I(inode)->cache_lru_lock); +} + +static inline int cache_contiguous(struct fat_cache_id *cid, int dclus) +{ + cid->nr_contig++; + return ((cid->dcluster + cid->nr_contig) == dclus); +} + +static inline void cache_init(struct fat_cache_id *cid, int fclus, int dclus) +{ + cid->id = FAT_CACHE_VALID; + cid->fcluster = fclus; + cid->dcluster = dclus; + cid->nr_contig = 0; +} + +int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus) +{ + struct super_block *sb = inode->i_sb; + struct msdos_sb_info *sbi = MSDOS_SB(sb); + const int limit = sb->s_maxbytes >> sbi->cluster_bits; + struct fat_entry fatent; + struct fat_cache_id cid; + int nr; + + BUG_ON(MSDOS_I(inode)->i_start == 0); + + *fclus = 0; + *dclus = MSDOS_I(inode)->i_start; + if (!fat_valid_entry(sbi, *dclus)) { + fat_fs_error_ratelimit(sb, + "%s: invalid start cluster (i_pos %lld, start %08x)", + __func__, MSDOS_I(inode)->i_pos, *dclus); + return -EIO; + } + if (cluster == 0) + return 0; + + if (fat_cache_lookup(inode, cluster, &cid, fclus, dclus) < 0) { + /* + * dummy, always not contiguous + * This is reinitialized by cache_init(), later. + */ + cache_init(&cid, -1, -1); + } + + fatent_init(&fatent); + while (*fclus < cluster) { + /* prevent the infinite loop of cluster chain */ + if (*fclus > limit) { + fat_fs_error_ratelimit(sb, + "%s: detected the cluster chain loop (i_pos %lld)", + __func__, MSDOS_I(inode)->i_pos); + nr = -EIO; + goto out; + } + + nr = fat_ent_read(inode, &fatent, *dclus); + if (nr < 0) + goto out; + else if (nr == FAT_ENT_FREE) { + fat_fs_error_ratelimit(sb, + "%s: invalid cluster chain (i_pos %lld)", + __func__, MSDOS_I(inode)->i_pos); + nr = -EIO; + goto out; + } else if (nr == FAT_ENT_EOF) { + fat_cache_add(inode, &cid); + goto out; + } + (*fclus)++; + *dclus = nr; + if (!cache_contiguous(&cid, *dclus)) + cache_init(&cid, *fclus, *dclus); + } + nr = 0; + fat_cache_add(inode, &cid); +out: + fatent_brelse(&fatent); + return nr; +} + +static int fat_bmap_cluster(struct inode *inode, int cluster) +{ + struct super_block *sb = inode->i_sb; + int ret, fclus, dclus; + + if (MSDOS_I(inode)->i_start == 0) + return 0; + + ret = fat_get_cluster(inode, cluster, &fclus, &dclus); + if (ret < 0) + return ret; + else if (ret == FAT_ENT_EOF) { + fat_fs_error(sb, "%s: request beyond EOF (i_pos %lld)", + __func__, MSDOS_I(inode)->i_pos); + return -EIO; + } + return dclus; +} + +int fat_get_mapped_cluster(struct inode *inode, sector_t sector, + sector_t last_block, + unsigned long *mapped_blocks, sector_t *bmap) +{ + struct super_block *sb = inode->i_sb; + struct msdos_sb_info *sbi = MSDOS_SB(sb); + int cluster, offset; + + cluster = sector >> (sbi->cluster_bits - sb->s_blocksize_bits); + offset = sector & (sbi->sec_per_clus - 1); + cluster = fat_bmap_cluster(inode, cluster); + if (cluster < 0) + return cluster; + else if (cluster) { + *bmap = fat_clus_to_blknr(sbi, cluster) + offset; + *mapped_blocks = sbi->sec_per_clus - offset; + if (*mapped_blocks > last_block - sector) + *mapped_blocks = last_block - sector; + } + + return 0; +} + +static int is_exceed_eof(struct inode *inode, sector_t sector, + sector_t *last_block, int create) +{ + struct super_block *sb = inode->i_sb; + const unsigned long blocksize = sb->s_blocksize; + const unsigned char blocksize_bits = sb->s_blocksize_bits; + + *last_block = (i_size_read(inode) + (blocksize - 1)) >> blocksize_bits; + if (sector >= *last_block) { + if (!create) + return 1; + + /* + * ->mmu_private can access on only allocation path. + * (caller must hold ->i_mutex) + */ + *last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1)) + >> blocksize_bits; + if (sector >= *last_block) + return 1; + } + + return 0; +} + +int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, + unsigned long *mapped_blocks, int create, bool from_bmap) +{ + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); + sector_t last_block; + + *phys = 0; + *mapped_blocks = 0; + if (!is_fat32(sbi) && (inode->i_ino == MSDOS_ROOT_INO)) { + if (sector < (sbi->dir_entries >> sbi->dir_per_block_bits)) { + *phys = sector + sbi->dir_start; + *mapped_blocks = 1; + } + return 0; + } + + if (!from_bmap) { + if (is_exceed_eof(inode, sector, &last_block, create)) + return 0; + } else { + last_block = inode->i_blocks >> + (inode->i_sb->s_blocksize_bits - 9); + if (sector >= last_block) + return 0; + } + + return fat_get_mapped_cluster(inode, sector, last_block, mapped_blocks, + phys); +} -- cgit v1.3.1