[U-Boot] [PATCH 07/17] fs: fat: support write with sub-directory path
AKASHI Takahiro
takahiro.akashi at linaro.org
Fri Jul 20 02:57:13 UTC 2018
In this patch, write implementation is overhauled and rewritten by
making full use of directory iterator. The ovbious bonus is that we are
now able to write to a file with a directory path, like /A/B/C/FILE.
Please note that, as there is no notion of "current directory" on u-boot,
a file name specified must contain an absolute directory path. Otherwise,
"/" (root directory) is assumed.
Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
fs/fat/fat.c | 9 -
fs/fat/fat_write.c | 469 +++++++++++++++------------------------------
2 files changed, 157 insertions(+), 321 deletions(-)
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index d9bfb08d97..9bafc3a40c 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -464,15 +464,6 @@ static __u8 mkcksum(const char name[8], const char ext[3])
return ret;
}
-/*
- * TODO these should go away once fat_write is reworked to use the
- * directory iterator
- */
-__u8 get_dentfromdir_block[MAX_CLUSTSIZE]
- __aligned(ARCH_DMA_MINALIGN);
-__u8 do_fat_read_at_block[MAX_CLUSTSIZE]
- __aligned(ARCH_DMA_MINALIGN);
-
/*
* Read boot sector and volume info from a FAT filesystem
*/
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 1e4f5af910..96edb6674c 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -99,7 +99,6 @@ static void set_name(dir_entry *dirent, const char *filename)
debug("ext : %s\n", dirent->ext);
}
-static __u8 num_of_fats;
/*
* Write fat buffer into block device
*/
@@ -128,7 +127,7 @@ static int flush_dirty_fat_buffer(fsdata *mydata)
return -1;
}
- if (num_of_fats == 2) {
+ if (mydata->bs_fats == 2) {
/* Update corresponding second FAT blocks */
startblock += mydata->fatlength;
if (disk_write(startblock, getsize, bufptr) < 0) {
@@ -210,15 +209,14 @@ name11_12:
return 1;
}
-static int is_next_clust(fsdata *mydata, dir_entry *dentptr);
-static void flush_dir_table(fsdata *mydata, dir_entry **dentptr);
+static int flush_dir_table(fat_itr *itr);
/*
* Fill dir_slot entries with appropriate name, id, and attr
- * The real directory entry is returned by 'dentptr'
+ * 'itr' will point to a next entry
*/
-static void
-fill_dir_slot(fsdata *mydata, dir_entry **dentptr, const char *l_name)
+static int
+fill_dir_slot(fat_itr *itr, const char *l_name)
{
__u8 temp_dir_slot_buffer[MAX_LFN_SLOT * sizeof(dir_slot)];
dir_slot *slotptr = (dir_slot *)temp_dir_slot_buffer;
@@ -226,7 +224,7 @@ fill_dir_slot(fsdata *mydata, dir_entry **dentptr, const char *l_name)
int idx = 0, ret;
/* Get short file name checksum value */
- checksum = mkcksum((*dentptr)->name, (*dentptr)->ext);
+ checksum = mkcksum(itr->dent->name, itr->dent->ext);
do {
memset(slotptr, 0x00, sizeof(dir_slot));
@@ -241,120 +239,21 @@ fill_dir_slot(fsdata *mydata, dir_entry **dentptr, const char *l_name)
slotptr->id |= LAST_LONG_ENTRY_MASK;
while (counter >= 1) {
- if (is_next_clust(mydata, *dentptr)) {
- /* A new cluster is allocated for directory table */
- flush_dir_table(mydata, dentptr);
- }
- memcpy(*dentptr, slotptr, sizeof(dir_slot));
- (*dentptr)++;
+ memcpy(itr->dent, slotptr, sizeof(dir_slot));
slotptr--;
counter--;
- }
-
- if (is_next_clust(mydata, *dentptr)) {
- /* A new cluster is allocated for directory table */
- flush_dir_table(mydata, dentptr);
- }
-}
-
-static __u32 dir_curclust;
-
-/*
- * Extract the full long filename starting at 'retdent' (which is really
- * a slot) into 'l_name'. If successful also copy the real directory entry
- * into 'retdent'
- * If additional adjacent cluster for directory entries is read into memory,
- * then 'get_contents_vfatname_block' is copied into 'get_dentfromdir_block' and
- * the location of the real directory entry is returned by 'retdent'
- * Return 0 on success, -1 otherwise.
- */
-static int
-get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
- dir_entry **retdent, char *l_name)
-{
- dir_entry *realdent;
- dir_slot *slotptr = (dir_slot *)(*retdent);
- dir_slot *slotptr2 = NULL;
- __u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
- PREFETCH_BLOCKS :
- mydata->clust_size);
- __u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
- int idx = 0, cur_position = 0;
-
- if (counter > VFAT_MAXSEQ) {
- debug("Error: VFAT name is too long\n");
- return -1;
- }
-
- while ((__u8 *)slotptr < buflimit) {
- if (counter == 0)
- break;
- if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
- return -1;
- slotptr++;
- counter--;
- }
-
- if ((__u8 *)slotptr >= buflimit) {
- if (curclust == 0)
- return -1;
- curclust = get_fatent(mydata, dir_curclust);
- if (CHECK_CLUST(curclust, mydata->fatsize)) {
- debug("curclust: 0x%x\n", curclust);
- printf("Invalid FAT entry\n");
- return -1;
- }
-
- dir_curclust = curclust;
-
- if (get_cluster(mydata, curclust, get_contents_vfatname_block,
- mydata->clust_size * mydata->sect_size) != 0) {
- debug("Error: reading directory block\n");
- return -1;
- }
-
- slotptr2 = (dir_slot *)get_contents_vfatname_block;
- while (counter > 0) {
- if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
- & 0xff) != counter)
+ if (!fat_itr_next(itr))
+ if (!itr->dent && !itr->is_root && flush_dir_table(itr))
return -1;
- slotptr2++;
- counter--;
- }
-
- /* Save the real directory entry */
- realdent = (dir_entry *)slotptr2;
- while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
- slotptr2--;
- slot2str(slotptr2, l_name, &idx);
- }
- } else {
- /* Save the real directory entry */
- realdent = (dir_entry *)slotptr;
}
- do {
- slotptr--;
- if (slot2str(slotptr, l_name, &idx))
- break;
- } while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
-
- l_name[idx] = '\0';
- if (*l_name == DELETED_FLAG)
- *l_name = '\0';
- else if (*l_name == aRING)
- *l_name = DELETED_FLAG;
- downcase(l_name, INT_MAX);
-
- /* Return the real directory entry */
- *retdent = realdent;
-
- if (slotptr2) {
- memcpy(get_dentfromdir_block, get_contents_vfatname_block,
- mydata->clust_size * mydata->sect_size);
- cur_position = (__u8 *)realdent - get_contents_vfatname_block;
- *retdent = (dir_entry *) &get_dentfromdir_block[cur_position];
- }
+ if (!itr->dent && !itr->is_root)
+ /*
+ * don't care return value here because we have already
+ * finished completing an entry with name, only ending up
+ * no more entry left
+ */
+ flush_dir_table(itr);
return 0;
}
@@ -569,20 +468,20 @@ static int find_empty_cluster(fsdata *mydata)
}
/*
- * Write directory entries in 'get_dentfromdir_block' to block device
+ * Write directory entries in itr's buffer to block device
*/
-static void flush_dir_table(fsdata *mydata, dir_entry **dentptr)
+static int flush_dir_table(fat_itr *itr)
{
+ fsdata *mydata = itr->fsdata;
int dir_newclust = 0;
+ unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
- if (set_cluster(mydata, dir_curclust,
- get_dentfromdir_block,
- mydata->clust_size * mydata->sect_size) != 0) {
- printf("error: wrinting directory entry\n");
- return;
+ if (set_cluster(mydata, itr->clust, itr->block, bytesperclust) != 0) {
+ printf("error: writing directory entry\n");
+ return -1;
}
dir_newclust = find_empty_cluster(mydata);
- set_fatent_value(mydata, dir_curclust, dir_newclust);
+ set_fatent_value(mydata, itr->clust, dir_newclust);
if (mydata->fatsize == 32)
set_fatent_value(mydata, dir_newclust, 0xffffff8);
else if (mydata->fatsize == 16)
@@ -590,15 +489,19 @@ static void flush_dir_table(fsdata *mydata, dir_entry **dentptr)
else if (mydata->fatsize == 12)
set_fatent_value(mydata, dir_newclust, 0xff8);
- dir_curclust = dir_newclust;
+ itr->clust = dir_newclust;
+ itr->next_clust = dir_newclust;
if (flush_dirty_fat_buffer(mydata) < 0)
- return;
+ return -1;
+
+ memset(itr->block, 0x00, bytesperclust);
- memset(get_dentfromdir_block, 0x00,
- mydata->clust_size * mydata->sect_size);
+ itr->dent = (dir_entry *)itr->block;
+ itr->last_cluster = 1;
+ itr->remaining = bytesperclust / sizeof(dir_entry) - 1;
- *dentptr = (dir_entry *) get_dentfromdir_block;
+ return 0;
}
/*
@@ -764,139 +667,83 @@ static int check_overflow(fsdata *mydata, __u32 clustnum, loff_t size)
return 0;
}
-/*
- * Check if adding several entries exceed one cluster boundary
- */
-static int is_next_clust(fsdata *mydata, dir_entry *dentptr)
-{
- int cur_position;
-
- cur_position = (__u8 *)dentptr - get_dentfromdir_block;
-
- if (cur_position >= mydata->clust_size * mydata->sect_size)
- return 1;
- else
- return 0;
-}
-
-static dir_entry *empty_dentptr;
/*
* Find a directory entry based on filename or start cluster number
* If the directory entry is not found,
* the new position for writing a directory entry will be returned
*/
-static dir_entry *find_directory_entry(fsdata *mydata, int startsect,
- char *filename, dir_entry *retdent, __u32 start)
+static dir_entry *find_directory_entry(fat_itr *itr, char *filename)
{
- __u32 curclust = sect_to_clust(mydata, startsect);
-
- debug("get_dentfromdir: %s\n", filename);
+ int match = 0;
- while (1) {
- dir_entry *dentptr;
+ while (fat_itr_next(itr)) {
+ /* check both long and short name: */
+ if (!strcasecmp(filename, itr->name))
+ match = 1;
+ else if (itr->name != itr->s_name &&
+ !strcasecmp(filename, itr->s_name))
+ match = 1;
- int i;
+ if (!match)
+ continue;
- if (get_cluster(mydata, curclust, get_dentfromdir_block,
- mydata->clust_size * mydata->sect_size) != 0) {
- printf("Error: reading directory block\n");
+ if (itr->dent->name[0] == '\0')
return NULL;
- }
-
- dentptr = (dir_entry *)get_dentfromdir_block;
-
- dir_curclust = curclust;
-
- for (i = 0; i < DIRENTSPERCLUST; i++) {
- char s_name[14], l_name[VFAT_MAXLEN_BYTES];
-
- l_name[0] = '\0';
- if (dentptr->name[0] == DELETED_FLAG) {
- dentptr++;
- if (is_next_clust(mydata, dentptr))
- break;
- continue;
- }
- if ((dentptr->attr & ATTR_VOLUME)) {
- if ((dentptr->attr & ATTR_VFAT) &&
- (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
- get_long_file_name(mydata, curclust,
- get_dentfromdir_block,
- &dentptr, l_name);
- debug("vfatname: |%s|\n", l_name);
- } else {
- /* Volume label or VFAT entry */
- dentptr++;
- if (is_next_clust(mydata, dentptr))
- break;
- continue;
- }
- }
- if (dentptr->name[0] == 0) {
- debug("Dentname == NULL - %d\n", i);
- empty_dentptr = dentptr;
- return NULL;
- }
-
- get_name(dentptr, s_name);
-
- if (strncasecmp(filename, s_name, sizeof(s_name)) &&
- strncasecmp(filename, l_name, sizeof(l_name))) {
- debug("Mismatch: |%s|%s|\n",
- s_name, l_name);
- dentptr++;
- if (is_next_clust(mydata, dentptr))
- break;
- continue;
- }
+ else
+ return itr->dent;
+ }
- memcpy(retdent, dentptr, sizeof(dir_entry));
+ if (!itr->dent && !itr->is_root && flush_dir_table(itr))
+ /* indicate that allocating dent failed */
+ itr->dent = NULL;
- debug("DentName: %s", s_name);
- debug(", start: 0x%x", START(dentptr));
- debug(", size: 0x%x %s\n",
- FAT2CPU32(dentptr->size),
- (dentptr->attr & ATTR_DIR) ?
- "(DIR)" : "");
+ return NULL;
+}
- return dentptr;
+static int split_filename(char *filename, char **dirname, char **basename)
+{
+ char *p, *last_slash, *last_slash_cont;
+
+again:
+ p = filename;
+ last_slash = NULL;
+ last_slash_cont = NULL;
+ while (*p) {
+ if (ISDIRDELIM(*p)) {
+ last_slash = p;
+ last_slash_cont = p;
+ /* continuous slashes */
+ while (ISDIRDELIM(*p))
+ last_slash_cont = p++;
+ if (!*p)
+ break;
}
+ p++;
+ }
- /*
- * In FAT16/12, the root dir is locate before data area, shows
- * in following:
- * -------------------------------------------------------------
- * | Boot | FAT1 & 2 | Root dir | Data (start from cluster #2) |
- * -------------------------------------------------------------
- *
- * As a result if curclust is in Root dir, it is a negative
- * number or 0, 1.
- *
- */
- if (mydata->fatsize != 32 && (int)curclust <= 1) {
- /* Current clust is in root dir, set to next clust */
- curclust++;
- if ((int)curclust <= 1)
- continue; /* continue to find */
-
- /* Reach the end of root dir */
- empty_dentptr = dentptr;
- return NULL;
+ if (last_slash) {
+ if (last_slash_cont == (filename + strlen(filename) - 1)) {
+ /* remove trailing slashes */
+ *last_slash = '\0';
+ goto again;
}
- curclust = get_fatent(mydata, dir_curclust);
- if (IS_LAST_CLUST(curclust, mydata->fatsize)) {
- empty_dentptr = dentptr;
- return NULL;
- }
- if (CHECK_CLUST(curclust, mydata->fatsize)) {
- debug("curclust: 0x%x\n", curclust);
- debug("Invalid FAT entry\n");
- return NULL;
+ if (last_slash == filename) {
+ /* avoid ""(null) directory */
+ *dirname = "/";
+ } else {
+ *last_slash = '\0';
+ *dirname = filename;
}
+
+ *last_slash_cont = '\0';
+ *basename = last_slash_cont + 1;
+ } else {
+ *dirname = "/"; /* root by default */
+ *basename = filename;
}
- return NULL;
+ return 0;
}
static int normalize_longname(char *l_filename, const char *filename)
@@ -940,86 +787,60 @@ static int normalize_longname(char *l_filename, const char *filename)
static int do_fat_write(const char *filename, void *buffer, loff_t size,
loff_t *actwrite)
{
- dir_entry *dentptr, *retdent;
- __u32 startsect;
+ dir_entry *retdent;
__u32 start_cluster;
- boot_sector bs;
- volume_info volinfo;
- fsdata datablock;
+ fsdata datablock = { .fatbuf = NULL, };
fsdata *mydata = &datablock;
- int cursect;
+ fat_itr *itr = NULL;
int ret = -1;
+ char *filename_copy, *parent, *basename;
char l_filename[VFAT_MAXLEN_BYTES];
- *actwrite = size;
- dir_curclust = 0;
+ filename_copy = strdup(filename);
+ if (!filename_copy)
+ return -ENOMEM;
- if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
- debug("error: reading boot sector\n");
- return -EIO;
+ split_filename(filename_copy, &parent, &basename);
+ if (!strlen(basename)) {
+ ret = -EINVAL;
+ goto exit;
}
- total_sector = bs.total_sect;
- if (total_sector == 0)
- total_sector = (int)cur_part_info.size; /* cast of lbaint_t */
-
- if (mydata->fatsize == 32)
- mydata->fatlength = bs.fat32_length;
- else
- mydata->fatlength = bs.fat_length;
-
- mydata->fat_sect = bs.reserved;
-
- cursect = mydata->rootdir_sect
- = mydata->fat_sect + mydata->fatlength * bs.fats;
- num_of_fats = bs.fats;
-
- mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
- mydata->clust_size = bs.cluster_size;
-
- if (mydata->fatsize == 32) {
- mydata->data_begin = mydata->rootdir_sect -
- (mydata->clust_size * 2);
- } else {
- int rootdir_size;
-
- rootdir_size = ((bs.dir_entries[1] * (int)256 +
- bs.dir_entries[0]) *
- sizeof(dir_entry)) /
- mydata->sect_size;
- mydata->data_begin = mydata->rootdir_sect +
- rootdir_size -
- (mydata->clust_size * 2);
+ filename = basename;
+ if (normalize_longname(l_filename, filename)) {
+ printf("FAT: illegal filename (%s)\n", filename);
+ ret = -EINVAL;
+ goto exit;
}
- mydata->fatbufnum = -1;
- mydata->fat_dirty = 0;
- mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
- if (mydata->fatbuf == NULL) {
- debug("Error: allocating memory\n");
- return -ENOMEM;
+ itr = malloc_cache_aligned(sizeof(fat_itr));
+ if (!itr) {
+ ret = -ENOMEM;
+ goto exit;
}
- if (disk_read(cursect,
- (mydata->fatsize == 32) ?
- (mydata->clust_size) :
- PREFETCH_BLOCKS, do_fat_read_at_block) < 0) {
- debug("Error: reading rootdir block\n");
- ret = -EIO;
+ ret = fat_itr_root(itr, &datablock);
+ if (ret)
goto exit;
- }
- dentptr = (dir_entry *) do_fat_read_at_block;
- if (normalize_longname(l_filename, filename)) {
- printf("FAT: illegal filename (%s)\n", filename);
- ret = -EINVAL;
+ total_sector = datablock.bs_total_sect;
+ if (total_sector == 0)
+ total_sector = (int)cur_part_info.size; /* cast of lbaint_t */
+
+ ret = fat_itr_resolve(itr, parent, TYPE_DIR);
+ if (ret) {
+ printf("%s: doesn't exist (%d)\n", parent, ret);
goto exit;
}
- startsect = mydata->rootdir_sect;
- retdent = find_directory_entry(mydata, startsect,
- l_filename, dentptr, 0);
+ retdent = find_directory_entry(itr, l_filename);
+
if (retdent) {
+ if (fat_itr_isdir(itr)) {
+ ret = -EISDIR;
+ goto exit;
+ }
+
/* Update file size and start_cluster in a directory entry */
retdent->size = cpu_to_le32(size);
start_cluster = START(retdent);
@@ -1062,9 +883,31 @@ static int do_fat_write(const char *filename, void *buffer, loff_t size,
set_start_cluster(mydata, retdent, start_cluster);
}
} else {
+ /* Create a new file */
+
+ if (itr->is_root) {
+ /* root dir cannot have "." or ".." */
+ if (!strcmp(l_filename, ".") ||
+ !strcmp(l_filename, "..")) {
+ ret = -EINVAL;
+ goto exit;
+ }
+ }
+
+ if (!itr->dent) {
+ printf("Error: allocating new dir entry\n");
+ ret = -EIO;
+ goto exit;
+ }
+
+ memset(itr->dent, 0, sizeof(*itr->dent));
+
/* Set short name to set alias checksum field in dir_slot */
- set_name(empty_dentptr, filename);
- fill_dir_slot(mydata, &empty_dentptr, filename);
+ set_name(itr->dent, filename);
+ if (fill_dir_slot(itr, filename)) {
+ ret = -EIO;
+ goto exit;
+ }
if (size) {
ret = start_cluster = find_empty_cluster(mydata);
@@ -1085,10 +928,10 @@ static int do_fat_write(const char *filename, void *buffer, loff_t size,
}
/* Set attribute as archieve for regular file */
- fill_dentry(mydata, empty_dentptr, filename,
- start_cluster, size, 0x20);
+ fill_dentry(itr->fsdata, itr->dent, filename,
+ start_cluster, size, 0x20);
- retdent = empty_dentptr;
+ retdent = itr->dent;
}
ret = set_contents(mydata, retdent, buffer, size, actwrite);
@@ -1108,15 +951,17 @@ static int do_fat_write(const char *filename, void *buffer, loff_t size,
}
/* Write directory table to device */
- ret = set_cluster(mydata, dir_curclust, get_dentfromdir_block,
- mydata->clust_size * mydata->sect_size);
+ ret = set_cluster(mydata, itr->clust, itr->block,
+ mydata->clust_size * mydata->sect_size);
if (ret) {
printf("Error: writing directory entry\n");
ret = -EIO;
}
exit:
+ free(filename_copy);
free(mydata->fatbuf);
+ free(itr);
return ret;
}
--
2.17.0
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