Merge tag 'u-boot-atmel-fixes-2021.01-b' of https://gitlab.denx.de/u-boot/custodians...

[platform/kernel/u-boot.git] / fs / fat / fat.c

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 06c8ed1..fb6ba89 100644 (file)
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -14,10 +14,12 @@
 #include <exports.h>
 #include <fat.h>
 #include <fs.h>
+#include <log.h>
 #include <asm/byteorder.h>
 #include <part.h>
 #include <malloc.h>
 #include <memalign.h>
+#include <asm/cache.h>
 #include <linux/compiler.h>
 #include <linux/ctype.h>
 
@@ -35,7 +37,7 @@ static void downcase(char *str, size_t len)
 }
 
 static struct blk_desc *cur_dev;
-static disk_partition_t cur_part_info;
+static struct disk_partition cur_part_info;
 
 #define DOS_BOOT_MAGIC_OFFSET  0x1fe
 #define DOS_FS_TYPE_OFFSET     0x36
@@ -56,7 +58,7 @@ static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
        return ret;
 }
 
-int fat_set_blk_dev(struct blk_desc *dev_desc, disk_partition_t *info)
+int fat_set_blk_dev(struct blk_desc *dev_desc, struct disk_partition *info)
 {
        ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
 
@@ -87,7 +89,7 @@ int fat_set_blk_dev(struct blk_desc *dev_desc, disk_partition_t *info)
 
 int fat_register_device(struct blk_desc *dev_desc, int part_no)
 {
-       disk_partition_t info;
+       struct disk_partition info;
 
        /* First close any currently found FAT filesystem */
        cur_dev = NULL;
@@ -276,7 +278,10 @@ get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
                }
        } else {
                idx = size / mydata->sect_size;
-               ret = disk_read(startsect, idx, buffer);
+               if (idx == 0)
+                       ret = 0;
+               else
+                       ret = disk_read(startsect, idx, buffer);
                if (ret != idx) {
                        debug("Error reading data (got %d)\n", ret);
                        return -1;
@@ -301,10 +306,20 @@ get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
        return 0;
 }
 
-/*
+/**
+ * get_contents() - read from file
+ *
  * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
- * into 'buffer'.
- * Update the number of bytes read in *gotsize or return -1 on fatal errors.
+ * into 'buffer'. Update the number of bytes read in *gotsize or return -1 on
+ * fatal errors.
+ *
+ * @mydata:    file system description
+ * @dentprt:   directory entry pointer
+ * @pos:       position from where to read
+ * @buffer:    buffer into which to read
+ * @maxsize:   maximum number of bytes to read
+ * @gotsize:   number of bytes actually read
+ * Return:     -1 on error, otherwise 0
  */
 static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
                        __u8 *buffer, loff_t maxsize, loff_t *gotsize)
@@ -335,8 +350,8 @@ static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
                curclust = get_fatent(mydata, curclust);
                if (CHECK_CLUST(curclust, mydata->fatsize)) {
                        debug("curclust: 0x%x\n", curclust);
-                       debug("Invalid FAT entry\n");
-                       return 0;
+                       printf("Invalid FAT entry\n");
+                       return -1;
                }
                actsize += bytesperclust;
        }
@@ -354,7 +369,7 @@ static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
                tmp_buffer = malloc_cache_aligned(actsize);
                if (!tmp_buffer) {
                        debug("Error: allocating buffer\n");
-                       return -ENOMEM;
+                       return -1;
                }
 
                if (get_cluster(mydata, curclust, tmp_buffer, actsize) != 0) {
@@ -374,8 +389,8 @@ static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
                curclust = get_fatent(mydata, curclust);
                if (CHECK_CLUST(curclust, mydata->fatsize)) {
                        debug("curclust: 0x%x\n", curclust);
-                       debug("Invalid FAT entry\n");
-                       return 0;
+                       printf("Invalid FAT entry\n");
+                       return -1;
                }
        }
 
@@ -390,8 +405,8 @@ static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
                                goto getit;
                        if (CHECK_CLUST(newclust, mydata->fatsize)) {
                                debug("curclust: 0x%x\n", newclust);
-                               debug("Invalid FAT entry\n");
-                               return 0;
+                               printf("Invalid FAT entry\n");
+                               return -1;
                        }
                        endclust = newclust;
                        actsize += bytesperclust;
@@ -418,7 +433,7 @@ getit:
                if (CHECK_CLUST(curclust, mydata->fatsize)) {
                        debug("curclust: 0x%x\n", curclust);
                        printf("Invalid FAT entry\n");
-                       return 0;
+                       return -1;
                }
                actsize = bytesperclust;
                endclust = curclust;
@@ -859,6 +874,14 @@ static dir_entry *extract_vfat_name(fat_itr *itr)
                        return NULL;
        }
 
+       /*
+        * We are now at the short file name entry.
+        * If it is marked as deleted, just skip it.
+        */
+       if (dent->name[0] == DELETED_FLAG ||
+           dent->name[0] == aRING)
+               return NULL;
+
        itr->l_name[n] = '\0';
 
        chksum = mkcksum(dent->name, dent->ext);
@@ -888,19 +911,38 @@ static int fat_itr_next(fat_itr *itr)
 
        itr->name = NULL;
 
+       /*
+        * One logical directory entry consist of following slots:
+        *                              name[0] Attributes
+        *   dent[N - N]: LFN[N - 1]    N|0x40  ATTR_VFAT
+        *   ...
+        *   dent[N - 2]: LFN[1]        2       ATTR_VFAT
+        *   dent[N - 1]: LFN[0]        1       ATTR_VFAT
+        *   dent[N]:     SFN                   ATTR_ARCH
+        */
+
        while (1) {
                dent = next_dent(itr);
                if (!dent)
                        return 0;
 
-               if (dent->name[0] == DELETED_FLAG ||
-                   dent->name[0] == aRING)
+               if (dent->name[0] == DELETED_FLAG)
                        continue;
 
                if (dent->attr & ATTR_VOLUME) {
                        if ((dent->attr & ATTR_VFAT) == ATTR_VFAT &&
                            (dent->name[0] & LAST_LONG_ENTRY_MASK)) {
+                               /* long file name */
                                dent = extract_vfat_name(itr);
+                               /*
+                                * If succeeded, dent has a valid short file
+                                * name entry for the current entry.
+                                * If failed, itr points to a current bogus
+                                * entry. So after fetching a next one,
+                                * it may have a short file name entry
+                                * for this bogus entry so that we can still
+                                * check for a short name.
+                                */
                                if (!dent)
                                        continue;
                                itr->name = itr->l_name;
@@ -911,6 +953,7 @@ static int fat_itr_next(fat_itr *itr)
                        }
                }
 
+               /* short file name */
                break;
        }
 
@@ -1174,10 +1217,6 @@ int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
        /* For saving default max clustersize memory allocated to malloc pool */
        dir_entry *dentptr = itr->dent;
 
-       free(itr);
-
-       itr = NULL;
-
        ret = get_contents(&fsdata, dentptr, pos, buffer, maxsize, actread);
 
 out_free_both: