diff options
Diffstat (limited to 'fs/fat/fat.c')
-rw-r--r-- | fs/fat/fat.c | 130 |
1 files changed, 95 insertions, 35 deletions
diff --git a/fs/fat/fat.c b/fs/fat/fat.c index fb6ba89466..47344bb57e 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -621,7 +621,7 @@ static int get_fs_info(fsdata *mydata) /* * The root directory is not cluster-aligned and may be on a * "negative" cluster, this will be handled specially in - * next_cluster(). + * fat_next_cluster(). */ mydata->root_cluster = 0; } @@ -647,44 +647,88 @@ static int get_fs_info(fsdata *mydata) return 0; } - -/* - * Directory iterator, to simplify filesystem traversal +/** + * struct fat_itr - directory iterator, to simplify filesystem traversal * * Implements an iterator pattern to traverse directory tables, * transparently handling directory tables split across multiple * clusters, and the difference between FAT12/FAT16 root directory * (contiguous) and subdirectories + FAT32 root (chained). * - * Rough usage: + * Rough usage + * + * .. code-block:: c * - * for (fat_itr_root(&itr, fsdata); fat_itr_next(&itr); ) { - * // to traverse down to a subdirectory pointed to by - * // current iterator position: - * fat_itr_child(&itr, &itr); - * } + * for (fat_itr_root(&itr, fsdata); fat_itr_next(&itr); ) { + * // to traverse down to a subdirectory pointed to by + * // current iterator position: + * fat_itr_child(&itr, &itr); + * } * - * For more complete example, see fat_itr_resolve() + * For a more complete example, see fat_itr_resolve(). */ - -typedef struct { - fsdata *fsdata; /* filesystem parameters */ - unsigned start_clust; /* first cluster */ - unsigned clust; /* current cluster */ - unsigned next_clust; /* next cluster if remaining == 0 */ - int last_cluster; /* set once we've read last cluster */ - int is_root; /* is iterator at root directory */ - int remaining; /* remaining dent's in current cluster */ - - /* current iterator position values: */ - dir_entry *dent; /* current directory entry */ - char l_name[VFAT_MAXLEN_BYTES]; /* long (vfat) name */ - char s_name[14]; /* short 8.3 name */ - char *name; /* l_name if there is one, else s_name */ - - /* storage for current cluster in memory: */ - u8 block[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN); -} fat_itr; +struct fat_itr { + /** + * @fsdata: filesystem parameters + */ + fsdata *fsdata; + /** + * @start_clust: first cluster + */ + unsigned int start_clust; + /** + * @clust: current cluster + */ + unsigned int clust; + /** + * @next_clust: next cluster if remaining == 0 + */ + unsigned int next_clust; + /** + * @last_cluster: set if last cluster of directory reached + */ + int last_cluster; + /** + * @is_root: is iterator at root directory + */ + int is_root; + /** + * @remaining: remaining directory entries in current cluster + */ + int remaining; + /** + * @dent: current directory entry + */ + dir_entry *dent; + /** + * @dent_rem: remaining entries after long name start + */ + int dent_rem; + /** + * @dent_clust: cluster of long name start + */ + unsigned int dent_clust; + /** + * @dent_start: first directory entry for long name + */ + dir_entry *dent_start; + /** + * @l_name: long name of current directory entry + */ + char l_name[VFAT_MAXLEN_BYTES]; + /** + * @s_name: short 8.3 name of current directory entry + */ + char s_name[14]; + /** + * @name: l_name if there is one, else s_name + */ + char *name; + /** + * @block: buffer for current cluster + */ + u8 block[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN); +}; static int fat_itr_isdir(fat_itr *itr); @@ -702,7 +746,7 @@ static int fat_itr_root(fat_itr *itr, fsdata *fsdata) return -ENXIO; itr->fsdata = fsdata; - itr->start_clust = 0; + itr->start_clust = fsdata->root_cluster; itr->clust = fsdata->root_cluster; itr->next_clust = fsdata->root_cluster; itr->dent = NULL; @@ -746,6 +790,7 @@ static void fat_itr_child(fat_itr *itr, fat_itr *parent) } else { itr->clust = parent->fsdata->root_cluster; itr->next_clust = parent->fsdata->root_cluster; + itr->start_clust = parent->fsdata->root_cluster; itr->is_root = 1; } itr->dent = NULL; @@ -753,7 +798,17 @@ static void fat_itr_child(fat_itr *itr, fat_itr *parent) itr->last_cluster = 0; } -static void *next_cluster(fat_itr *itr, unsigned *nbytes) +/** + * fat_next_cluster() - load next FAT cluster + * + * The function is used when iterating through directories. It loads the + * next cluster with directory entries + * + * @itr: directory iterator + * @nbytes: number of bytes read, 0 on error + * Return: first directory entry, NULL on error + */ +void *fat_next_cluster(fat_itr *itr, unsigned int *nbytes) { fsdata *mydata = itr->fsdata; /* for silly macros */ int ret; @@ -825,7 +880,7 @@ static dir_entry *next_dent(fat_itr *itr) { if (itr->remaining == 0) { unsigned nbytes; - struct dir_entry *dent = next_cluster(itr, &nbytes); + struct dir_entry *dent = fat_next_cluster(itr, &nbytes); /* have we reached the last cluster? */ if (!dent) { @@ -923,9 +978,13 @@ static int fat_itr_next(fat_itr *itr) while (1) { dent = next_dent(itr); - if (!dent) + if (!dent) { + itr->dent_start = NULL; return 0; - + } + itr->dent_rem = itr->remaining; + itr->dent_start = itr->dent; + itr->dent_clust = itr->clust; if (dent->name[0] == DELETED_FLAG) continue; @@ -1025,6 +1084,7 @@ static int fat_itr_resolve(fat_itr *itr, const char *path, unsigned type) /* point back to itself */ itr->clust = itr->fsdata->root_cluster; itr->next_clust = itr->fsdata->root_cluster; + itr->start_clust = itr->fsdata->root_cluster; itr->dent = NULL; itr->remaining = 0; itr->last_cluster = 0; |