fs: add fs_readdir()

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 <robdclark@gmail.com>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Rob Clark 2017-09-09 13:15:55 -04:00 committed by Tom Rini
parent 8eafae209c
commit 4bbcc965f9
4 changed files with 199 additions and 12 deletions

View File

@ -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;

104
fs/fs.c
View File

@ -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,
},
};
@ -226,6 +252,31 @@ int fs_set_blk_dev(const char *ifname, const char *dev_part_str, int fstype)
if (!fs_dev_desc && !info->null_dev_desc_ok)
continue;
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)
{

View File

@ -26,6 +26,17 @@
*/
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".
@ -78,6 +89,62 @@ int fs_read(const char *filename, ulong addr, loff_t offset, loff_t len,
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.

View File

@ -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) {}