[U-Boot] [PATCH v1 02/15] fs/fat: implement readdir
Rob Clark
robdclark at gmail.com
Thu Aug 10 18:29:30 UTC 2017
Yes, this is super-hacky. The FAT code is quite ugly, and this doesn't
improve things. But it doesn't make it significantly worse either. The
better option would be a massive FAT re-write to get rid of the hacky
way that fat_file_ls() works. Volunteers welcome.
Signed-off-by: Rob Clark <robdclark at gmail.com>
---
fs/fat/fat.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++-----------
fs/fs.c | 2 +-
include/fat.h | 4 ++-
3 files changed, 81 insertions(+), 19 deletions(-)
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 9ad18f96ff..3d5dde0d9e 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,
@@ -668,7 +684,7 @@ static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
}
if (vfat_enabled) {
__u8 csum = mkcksum(dentptr->name, dentptr->ext);
- if (dols && csum == prevcksum) {
+ if ((dols || readdir) && csum == prevcksum) {
prevcksum = 0xffff;
dentptr++;
continue;
@@ -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);
@@ -825,13 +848,14 @@ 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;
int rootdir_size = 0;
int buffer_blk_cnt;
int do_read;
+ int readdir = (dols == LS_READDIR);
__u8 *dir_ptr;
if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
@@ -1012,7 +1036,16 @@ root_reparse:
}
}
if (doit) {
- if (dirc == ' ') {
+ if (readdir) {
+ if ((dirs + files - 1) == pos) {
+ struct fs_dirent *d = buffer;
+ strcpy(d->name, l_name);
+ if (!isdir)
+ d->size = FAT2CPU32(dentptr->size);
+ ret = 0;
+ goto exit;
+ }
+ } else if (dirc == ' ') {
printf(" %8u %s%c\n",
FAT2CPU32(dentptr->size),
l_name,
@@ -1035,7 +1068,9 @@ root_reparse:
}
} else if (dentptr->name[0] == 0) {
debug("RootDentname == NULL - %d\n", i);
- if (dols == LS_ROOT) {
+ if (readdir) {
+ ret = -ENOENT;
+ } else if (dols == LS_ROOT) {
printf("\n%d file(s), %d dir(s)\n\n",
files, dirs);
ret = 0;
@@ -1070,7 +1105,16 @@ root_reparse:
}
}
if (doit) {
- if (dirc == ' ') {
+ if (readdir) {
+ if ((dirs + files - 1) == pos) {
+ struct fs_dirent *d = buffer;
+ strcpy(d->name, s_name);
+ if (!isdir)
+ d->size = FAT2CPU32(dentptr->size);
+ ret = 0;
+ goto exit;
+ }
+ } else if (dirc == ' ') {
printf(" %8u %s%c\n",
FAT2CPU32(dentptr->size),
s_name, dirc);
@@ -1138,7 +1182,9 @@ root_reparse:
/* If end of rootdir reached */
if (rootdir_end) {
- if (dols == LS_ROOT) {
+ if (readdir) {
+ ret = -ENOENT;
+ } else if (dols == LS_ROOT) {
printf("\n%d file(s), %d dir(s)\n\n",
files, dirs);
*size = 0;
@@ -1150,9 +1196,12 @@ rootdir_done:
firsttime = 1;
+ if (readdir && dols == LS_ROOT) {
+ ret = -ENOENT;
+ goto exit;
+ }
+
while (isdir) {
- int startsect = mydata->data_begin
- + START(dentptr) * mydata->clust_size;
dir_entry dent;
char *nextname = NULL;
@@ -1177,10 +1226,14 @@ 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 +1406,13 @@ 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 5720ceec49..d6a2cdb22f 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -119,7 +119,7 @@ static struct fstype_info fstypes[] = {
.write = fs_write_unsupported,
#endif
.uuid = fs_uuid_unsupported,
- .readdir = fs_readdir_unsupported,
+ .readdir = fat_readdir,
},
#endif
#ifdef CONFIG_FS_EXT4
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_ */
--
2.13.0
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