From 4bbcc965f995564870ca02606137e60e873e0a1f Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Sat, 9 Sep 2017 13:15:55 -0400 Subject: [PATCH] fs: add fs_readdir() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Needed to support efi file protocol. The fallback.efi loader wants to be able to read the contents of the /EFI directory to find an OS to boot. Modelled after POSIX opendir()/readdir()/closedir(). Unlike the other fs APIs, this is stateful (ie. state is held in the FS_DIR "directory stream"), to avoid re-traversing of the directory structure at each step. The directory stream must be released with closedir() when it is no longer needed. Signed-off-by: Rob Clark Reviewed-by: Łukasz Majewski Reviewed-by: Simon Glass --- disk/part.c | 31 ++++++++++------- fs/fs.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/fs.h | 67 +++++++++++++++++++++++++++++++++++++ include/part.h | 9 +++++ 4 files changed, 199 insertions(+), 12 deletions(-) diff --git a/disk/part.c b/disk/part.c index c67fdac..aa9183d 100644 --- a/disk/part.c +++ b/disk/part.c @@ -331,6 +331,24 @@ int part_get_info(struct blk_desc *dev_desc, int part, return -1; } +int part_get_info_whole_disk(struct blk_desc *dev_desc, disk_partition_t *info) +{ + info->start = 0; + info->size = dev_desc->lba; + info->blksz = dev_desc->blksz; + info->bootable = 0; + strcpy((char *)info->type, BOOT_PART_TYPE); + strcpy((char *)info->name, "Whole Disk"); +#if CONFIG_IS_ENABLED(PARTITION_UUIDS) + info->uuid[0] = 0; +#endif +#ifdef CONFIG_PARTITION_TYPE_GUID + info->type_guid[0] = 0; +#endif + + return 0; +} + int blk_get_device_by_str(const char *ifname, const char *dev_hwpart_str, struct blk_desc **dev_desc) { @@ -523,18 +541,7 @@ int blk_get_device_part_str(const char *ifname, const char *dev_part_str, (*dev_desc)->log2blksz = LOG2((*dev_desc)->blksz); - info->start = 0; - info->size = (*dev_desc)->lba; - info->blksz = (*dev_desc)->blksz; - info->bootable = 0; - strcpy((char *)info->type, BOOT_PART_TYPE); - strcpy((char *)info->name, "Whole Disk"); -#if CONFIG_IS_ENABLED(PARTITION_UUIDS) - info->uuid[0] = 0; -#endif -#ifdef CONFIG_PARTITION_TYPE_GUID - info->type_guid[0] = 0; -#endif + part_get_info_whole_disk(*dev_desc, info); ret = 0; goto cleanup; diff --git a/fs/fs.c b/fs/fs.c index 13cd362..fc0c953 100644 --- a/fs/fs.c +++ b/fs/fs.c @@ -21,6 +21,7 @@ DECLARE_GLOBAL_DATA_PTR; static struct blk_desc *fs_dev_desc; +static int fs_dev_part; static disk_partition_t fs_partition; static int fs_type = FS_TYPE_ANY; @@ -69,6 +70,12 @@ static inline int fs_uuid_unsupported(char *uuid_str) return -1; } +static inline int fs_opendir_unsupported(const char *filename, + struct fs_dir_stream **dirs) +{ + return -EACCES; +} + struct fstype_info { int fstype; char *name; @@ -92,6 +99,20 @@ struct fstype_info { loff_t len, loff_t *actwrite); void (*close)(void); int (*uuid)(char *uuid_str); + /* + * Open a directory stream. On success return 0 and directory + * stream pointer via 'dirsp'. On error, return -errno. See + * fs_opendir(). + */ + int (*opendir)(const char *filename, struct fs_dir_stream **dirsp); + /* + * Read next entry from directory stream. On success return 0 + * and directory entry pointer via 'dentp'. On error return + * -errno. See fs_readdir(). + */ + int (*readdir)(struct fs_dir_stream *dirs, struct fs_dirent **dentp); + /* see fs_closedir() */ + void (*closedir)(struct fs_dir_stream *dirs); }; static struct fstype_info fstypes[] = { @@ -112,6 +133,7 @@ static struct fstype_info fstypes[] = { .write = fs_write_unsupported, #endif .uuid = fs_uuid_unsupported, + .opendir = fs_opendir_unsupported, }, #endif #ifdef CONFIG_FS_EXT4 @@ -131,6 +153,7 @@ static struct fstype_info fstypes[] = { .write = fs_write_unsupported, #endif .uuid = ext4fs_uuid, + .opendir = fs_opendir_unsupported, }, #endif #ifdef CONFIG_SANDBOX @@ -146,6 +169,7 @@ static struct fstype_info fstypes[] = { .read = fs_read_sandbox, .write = fs_write_sandbox, .uuid = fs_uuid_unsupported, + .opendir = fs_opendir_unsupported, }, #endif #ifdef CONFIG_CMD_UBIFS @@ -161,6 +185,7 @@ static struct fstype_info fstypes[] = { .read = ubifs_read, .write = fs_write_unsupported, .uuid = fs_uuid_unsupported, + .opendir = fs_opendir_unsupported, }, #endif { @@ -175,6 +200,7 @@ static struct fstype_info fstypes[] = { .read = fs_read_unsupported, .write = fs_write_unsupported, .uuid = fs_uuid_unsupported, + .opendir = fs_opendir_unsupported, }, }; @@ -228,6 +254,31 @@ int fs_set_blk_dev(const char *ifname, const char *dev_part_str, int fstype) if (!info->probe(fs_dev_desc, &fs_partition)) { fs_type = info->fstype; + fs_dev_part = part; + return 0; + } + } + + return -1; +} + +/* set current blk device w/ blk_desc + partition # */ +int fs_set_blk_dev_with_part(struct blk_desc *desc, int part) +{ + struct fstype_info *info; + int ret, i; + + if (part >= 1) + ret = part_get_info(desc, part, &fs_partition); + else + ret = part_get_info_whole_disk(desc, &fs_partition); + if (ret) + return ret; + fs_dev_desc = desc; + + for (i = 0, info = fstypes; i < ARRAY_SIZE(fstypes); i++, info++) { + if (!info->probe(fs_dev_desc, &fs_partition)) { + fs_type = info->fstype; return 0; } } @@ -334,6 +385,59 @@ int fs_write(const char *filename, ulong addr, loff_t offset, loff_t len, return ret; } +struct fs_dir_stream *fs_opendir(const char *filename) +{ + struct fstype_info *info = fs_get_info(fs_type); + struct fs_dir_stream *dirs = NULL; + int ret; + + ret = info->opendir(filename, &dirs); + fs_close(); + if (ret) { + errno = -ret; + return NULL; + } + + dirs->desc = fs_dev_desc; + dirs->part = fs_dev_part; + + return dirs; +} + +struct fs_dirent *fs_readdir(struct fs_dir_stream *dirs) +{ + struct fstype_info *info; + struct fs_dirent *dirent; + int ret; + + fs_set_blk_dev_with_part(dirs->desc, dirs->part); + info = fs_get_info(fs_type); + + ret = info->readdir(dirs, &dirent); + fs_close(); + if (ret) { + errno = -ret; + return NULL; + } + + return dirent; +} + +void fs_closedir(struct fs_dir_stream *dirs) +{ + struct fstype_info *info; + + if (!dirs) + return; + + fs_set_blk_dev_with_part(dirs->desc, dirs->part); + info = fs_get_info(fs_type); + + info->closedir(dirs); + fs_close(); +} + + int do_size(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[], int fstype) { diff --git a/include/fs.h b/include/fs.h index 2f2aca8..0869ad6 100644 --- a/include/fs.h +++ b/include/fs.h @@ -27,6 +27,17 @@ int fs_set_blk_dev(const char *ifname, const char *dev_part_str, int fstype); /* + * fs_set_blk_dev_with_part - Set current block device + partition + * + * Similar to fs_set_blk_dev(), but useful for cases where you already + * know the blk_desc and part number. + * + * Returns 0 on success. + * Returns non-zero if invalid partition or error accessing the disk. + */ +int fs_set_blk_dev_with_part(struct blk_desc *desc, int part); + +/* * Print the list of files on the partition previously set by fs_set_blk_dev(), * in directory "dirname". * @@ -79,6 +90,62 @@ int fs_write(const char *filename, ulong addr, loff_t offset, loff_t len, loff_t *actwrite); /* + * Directory entry types, matches the subset of DT_x in posix readdir() + * which apply to u-boot. + */ +#define FS_DT_DIR 4 /* directory */ +#define FS_DT_REG 8 /* regular file */ +#define FS_DT_LNK 10 /* symbolic link */ + +/* + * A directory entry, returned by fs_readdir(). Returns information + * about the file/directory at the current directory entry position. + */ +struct fs_dirent { + unsigned type; /* one of FS_DT_x (not a mask) */ + loff_t size; /* size in bytes */ + char name[256]; +}; + +/* Note: fs_dir_stream should be treated as opaque to the user of fs layer */ +struct fs_dir_stream { + /* private to fs. layer: */ + struct blk_desc *desc; + int part; +}; + +/* + * fs_opendir - Open a directory + * + * @filename: the path to directory to open + * @return a pointer to the directory stream or NULL on error and errno + * set appropriately + */ +struct fs_dir_stream *fs_opendir(const char *filename); + +/* + * fs_readdir - Read the next directory entry in the directory stream. + * + * Works in an analogous way to posix readdir(). The previously returned + * directory entry is no longer valid after calling fs_readdir() again. + * After fs_closedir() is called, the returned directory entry is no + * longer valid. + * + * @dirs: the directory stream + * @return the next directory entry (only valid until next fs_readdir() or + * fs_closedir() call, do not attempt to free()) or NULL if the end of + * the directory is reached. + */ +struct fs_dirent *fs_readdir(struct fs_dir_stream *dirs); + +/* + * fs_closedir - close a directory stream + * + * @dirs: the directory stream + */ +void fs_closedir(struct fs_dir_stream *dirs); + +/* * Common implementation for various filesystem commands, optionally limited * to a specific filesystem type via the fstype parameter. */ diff --git a/include/part.h b/include/part.h index 0d5c998..86117a7 100644 --- a/include/part.h +++ b/include/part.h @@ -98,6 +98,12 @@ int host_get_dev_err(int dev, struct blk_desc **blk_devp); /* disk/part.c */ int part_get_info(struct blk_desc *dev_desc, int part, disk_partition_t *info); +/** + * part_get_info_whole_disk() - get partition info for the special case of + * a partition occupying the entire disk. + */ +int part_get_info_whole_disk(struct blk_desc *dev_desc, disk_partition_t *info); + void part_print(struct blk_desc *dev_desc); void part_init(struct blk_desc *dev_desc); void dev_print(struct blk_desc *dev_desc); @@ -203,6 +209,9 @@ static inline struct blk_desc *mg_disk_get_dev(int dev) { return NULL; } static inline int part_get_info(struct blk_desc *dev_desc, int part, disk_partition_t *info) { return -1; } +static inline int part_get_info_whole_disk(struct blk_desc *dev_desc, + disk_partition_t *info) +{ return -1; } static inline void part_print(struct blk_desc *dev_desc) {} static inline void part_init(struct blk_desc *dev_desc) {} static inline void dev_print(struct blk_desc *dev_desc) {}