diff options
| -rw-r--r-- | fs/exfat/cache.c | 56 | ||||
| -rw-r--r-- | fs/exfat/exfat_fs.h | 2 | ||||
| -rw-r--r-- | fs/exfat/inode.c | 3 |
3 files changed, 53 insertions, 8 deletions
diff --git a/fs/exfat/cache.c b/fs/exfat/cache.c index 5cdeac014a3d..7c8b4182f5de 100644 --- a/fs/exfat/cache.c +++ b/fs/exfat/cache.c @@ -259,13 +259,15 @@ static inline void cache_init(struct exfat_cache_id *cid, } int exfat_get_cluster(struct inode *inode, unsigned int cluster, - unsigned int *dclus, unsigned int *last_dclus) + 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, @@ -279,17 +281,33 @@ int exfat_get_cluster(struct inode *inode, unsigned int cluster, *last_dclus = *dclus; /* - * Don`t use exfat_cache if zero offset or non-cluster allocation + * 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 (cluster == 0 || *dclus == EXFAT_EOF_CLUSTER) + 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); - exfat_cache_lookup(inode, &cid, cluster, cluster, &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); - if (fclus == cluster) + /* 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; @@ -305,6 +323,34 @@ int exfat_get_cluster(struct inode *inode, unsigned int cluster, 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; diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h index e58d8eed5495..2dbed5f8ec26 100644 --- a/fs/exfat/exfat_fs.h +++ b/fs/exfat/exfat_fs.h @@ -486,7 +486,7 @@ int exfat_cache_init(void); void exfat_cache_shutdown(void); void exfat_cache_inval_inode(struct inode *inode); int exfat_get_cluster(struct inode *inode, unsigned int cluster, - unsigned int *dclus, unsigned int *last_dclus); + unsigned int *dclus, unsigned int *count, unsigned int *last_dclus); /* dir.c */ extern const struct inode_operations exfat_dir_inode_operations; diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c index 410f9c98b8dc..86bce7ea2725 100644 --- a/fs/exfat/inode.c +++ b/fs/exfat/inode.c @@ -160,10 +160,9 @@ static int exfat_map_cluster(struct inode *inode, unsigned int clu_offset, } } else { int err = exfat_get_cluster(inode, clu_offset, - clu, &last_clu); + clu, count, &last_clu); if (err) return -EIO; - *count = (*clu == EXFAT_EOF_CLUSTER) ? 0 : 1; } if (*clu == EXFAT_EOF_CLUSTER) { |