[U-Boot] [RFC 04/10] fs: add fs_readdir()
Rob Clark
robdclark at gmail.com
Thu Jul 27 21:38:01 UTC 2017
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.
Currently only implemented for FAT, but that is all that UEFI is
required to support.
Signed-off-by: Rob Clark <robdclark at gmail.com>
---
fs/fat/fat.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++-------------
fs/fs.c | 25 +++++++++++++++++++++++++
include/fat.h | 4 +++-
include/fs.h | 21 +++++++++++++++++++++
4 files changed, 95 insertions(+), 14 deletions(-)
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 9ad18f96ff..04d8616598 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -14,6 +14,7 @@
#include <config.h>
#include <exports.h>
#include <fat.h>
+#include <fs.h>
#include <asm/byteorder.h>
#include <part.h>
#include <malloc.h>
@@ -575,17 +576,25 @@ static __u8 mkcksum(const char name[8], const char ext[3])
/*
* Get the directory entry associated with 'filename' from the directory
* starting at 'startsect'
+ *
+ * Last two args are only used for dols==LS_READDIR
*/
__u8 get_dentfromdir_block[MAX_CLUSTSIZE]
__aligned(ARCH_DMA_MINALIGN);
-static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
- char *filename, dir_entry *retdent,
- int dols)
+static dir_entry *get_dentfromdir(fsdata *mydata, char *filename,
+ dir_entry *retdent, int dols,
+ loff_t pos, struct fs_dirent *d)
{
__u16 prevcksum = 0xffff;
__u32 curclust = START(retdent);
int files = 0, dirs = 0;
+ int readdir = 0;
+
+ if (dols == LS_READDIR) {
+ readdir = 1;
+ dols = 0;
+ }
debug("get_dentfromdir: %s\n", filename);
@@ -618,7 +627,7 @@ static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
get_vfatname(mydata, curclust,
get_dentfromdir_block,
dentptr, l_name);
- if (dols) {
+ if (dols || readdir) {
int isdir;
char dirc;
int doit = 0;
@@ -637,7 +646,14 @@ static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
}
}
if (doit) {
- if (dirc == ' ') {
+ if (readdir) {
+ if ((dirs + files - 1) == pos) {
+ strcpy(d->name, l_name);
+ if (!isdir)
+ d->size = FAT2CPU32(dentptr->size);
+ return NULL;
+ }
+ } else if (dirc == ' ') {
printf(" %8u %s%c\n",
FAT2CPU32(dentptr->size),
l_name,
@@ -676,7 +692,7 @@ static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
}
get_name(dentptr, s_name);
- if (dols) {
+ if (dols || readdir) {
int isdir = (dentptr->attr & ATTR_DIR);
char dirc;
int doit = 0;
@@ -694,7 +710,14 @@ static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
}
if (doit) {
- if (dirc == ' ') {
+ if (readdir) {
+ if ((dirs + files - 1) == pos) {
+ strcpy(d->name, s_name);
+ if (!isdir)
+ d->size = FAT2CPU32(dentptr->size);
+ return NULL;
+ }
+ } else if (dirc == ' ') {
printf(" %8u %s%c\n",
FAT2CPU32(dentptr->size),
s_name, dirc);
@@ -825,7 +848,7 @@ int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
__u32 cursect;
int idx, isdir = 0;
int files = 0, dirs = 0;
- int ret = -1;
+ int ret = (dols == LS_READDIR) ? -ENOTDIR : -1;
int firsttime;
__u32 root_cluster = 0;
__u32 read_blk;
@@ -906,7 +929,8 @@ root_reparse:
if (!dols)
goto exit;
- dols = LS_ROOT;
+ if (dols == LS_YES)
+ dols = LS_ROOT;
} else if ((idx = dirdelim(fnamecopy)) >= 0) {
isdir = 1;
fnamecopy[idx] = '\0';
@@ -1151,8 +1175,6 @@ rootdir_done:
firsttime = 1;
while (isdir) {
- int startsect = mydata->data_begin
- + START(dentptr) * mydata->clust_size;
dir_entry dent;
char *nextname = NULL;
@@ -1177,10 +1199,14 @@ rootdir_done:
}
}
- if (get_dentfromdir(mydata, startsect, subname, dentptr,
- isdir ? 0 : dols) == NULL) {
+ if (get_dentfromdir(mydata, subname, dentptr,
+ isdir ? 0 : dols, pos, buffer) == NULL) {
if (dols && !isdir)
*size = 0;
+ if (dols == LS_READDIR) {
+ struct fs_dirent *dent = buffer;
+ ret = dent->name[0] ? 0 : -ENOENT;
+ }
goto exit;
}
@@ -1353,6 +1379,13 @@ int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
return ret;
}
+int fat_readdir(const char *filename, loff_t offset, struct fs_dirent *dent)
+{
+ loff_t actread;
+ return do_fat_read_at(filename, offset, dent, sizeof(*dent),
+ LS_READDIR, 0, &actread);
+}
+
void fat_close(void)
{
}
diff --git a/fs/fs.c b/fs/fs.c
index 595ff1fe69..42a028a6ce 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -69,6 +69,12 @@ static inline int fs_uuid_unsupported(char *uuid_str)
return -1;
}
+static inline int fs_readdir_unsupported(const char *filename, loff_t offset,
+ struct fs_dirent *dent)
+{
+ return -ENXIO;
+}
+
struct fstype_info {
int fstype;
char *name;
@@ -92,6 +98,7 @@ struct fstype_info {
loff_t len, loff_t *actwrite);
void (*close)(void);
int (*uuid)(char *uuid_str);
+ int (*readdir)(const char *filename, loff_t offset, struct fs_dirent *dent);
};
static struct fstype_info fstypes[] = {
@@ -112,6 +119,7 @@ static struct fstype_info fstypes[] = {
.write = fs_write_unsupported,
#endif
.uuid = fs_uuid_unsupported,
+ .readdir = fat_readdir,
},
#endif
#ifdef CONFIG_FS_EXT4
@@ -131,6 +139,7 @@ static struct fstype_info fstypes[] = {
.write = fs_write_unsupported,
#endif
.uuid = ext4fs_uuid,
+ .readdir = fs_readdir_unsupported,
},
#endif
#ifdef CONFIG_SANDBOX
@@ -146,6 +155,7 @@ static struct fstype_info fstypes[] = {
.read = fs_read_sandbox,
.write = fs_write_sandbox,
.uuid = fs_uuid_unsupported,
+ .readdir = fs_readdir_unsupported,
},
#endif
#ifdef CONFIG_CMD_UBIFS
@@ -161,6 +171,7 @@ static struct fstype_info fstypes[] = {
.read = ubifs_read,
.write = fs_write_unsupported,
.uuid = fs_uuid_unsupported,
+ .readdir = fs_readdir_unsupported,
},
#endif
{
@@ -175,6 +186,7 @@ static struct fstype_info fstypes[] = {
.read = fs_read_unsupported,
.write = fs_write_unsupported,
.uuid = fs_uuid_unsupported,
+ .readdir = fs_readdir_unsupported,
},
};
@@ -334,6 +346,19 @@ int fs_write(const char *filename, ulong addr, loff_t offset, loff_t len,
return ret;
}
+int fs_readdir(const char *filename, loff_t offset, struct fs_dirent *dent)
+{
+ struct fstype_info *info = fs_get_info(fs_type);
+ int ret;
+
+ memset(dent, 0, sizeof(*dent));
+
+ ret = info->readdir(filename, offset, dent);
+ fs_close();
+
+ return ret;
+}
+
int do_size(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
int fstype)
{
diff --git a/include/fat.h b/include/fat.h
index 71879f01ca..0ef3f5be16 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -61,8 +61,8 @@
/* Flags telling whether we should read a file or list a directory */
#define LS_NO 0
#define LS_YES 1
-#define LS_DIR 1
#define LS_ROOT 2
+#define LS_READDIR 3 /* read directory entry at specified offset */
#define ISDIRDELIM(c) ((c) == '/' || (c) == '\\')
@@ -210,5 +210,7 @@ int file_fat_write(const char *filename, void *buf, loff_t offset, loff_t len,
loff_t *actwrite);
int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
loff_t *actread);
+struct fs_dirent;
+int fat_readdir(const char *filename, loff_t offset, struct fs_dirent *dir);
void fat_close(void);
#endif /* _FAT_H_ */
diff --git a/include/fs.h b/include/fs.h
index 2f2aca8378..71051d7c66 100644
--- a/include/fs.h
+++ b/include/fs.h
@@ -79,6 +79,27 @@ int fs_write(const char *filename, ulong addr, loff_t offset, loff_t len,
loff_t *actwrite);
/*
+ * A directory entry.
+ */
+struct fs_dirent {
+ loff_t size;
+ char name[256];
+};
+
+/*
+ * fs_readdir - Read a directory.
+ *
+ * @filename: Name of file to read from
+ * @offset: The offset into the directory to read, ie. offset of N returns
+ * the N'th directory entry
+ * @dent: on success, filled in with directory entry
+ * @return 0 on success, -ENOTDIR if specified file is not a directory,
+ * or -ENOENT if offset is beyond last directory entry, or -ENXIO if
+ * operation is not supported.
+ */
+int fs_readdir(const char *filename, loff_t offset, struct fs_dirent *dent);
+
+/*
* Common implementation for various filesystem commands, optionally limited
* to a specific filesystem type via the fstype parameter.
*/
--
2.13.0
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