[U-Boot] [PATCH 2/2] fs/fat: merge readwrite get_fatent_value() with readonly get_fatent()
Stefan Brüns
stefan.bruens at rwth-aachen.de
Sun Dec 11 03:32:58 CET 2016
get_fatent_value(...) flushes changed FAT entries to disk when fetching
the next FAT blocks, in every other aspect it is identical to
get_fatent(...).
Provide a stub implementation for flush_dirty_fat_buffer if
CONFIG_FAT_WRITE is not set. Calling flush_dirty_fat_buffer during read
only operation is fine as it checks if any buffers needs flushing.
Signed-off-by: Stefan Brüns <stefan.bruens at rwth-aachen.de>
---
fs/fat/fat.c | 19 +++++++++
fs/fat/fat_write.c | 118 +++--------------------------------------------------
2 files changed, 24 insertions(+), 113 deletions(-)
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 6319581406..554e811587 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -162,6 +162,16 @@ static void get_name(dir_entry *dirent, char *s_name)
downcase(s_name);
}
+static int flush_dirty_fat_buffer(fsdata *mydata);
+#if !defined(CONFIG_FAT_WRITE)
+/* Stub for read only operation */
+int flush_dirty_fat_buffer(fsdata *mydata)
+{
+ (void)(mydata);
+ return 0;
+}
+#endif
+
/*
* Get the entry at index 'entry' in a FAT (12/16/32) table.
* On failure 0x00 is returned.
@@ -173,6 +183,11 @@ static __u32 get_fatent(fsdata *mydata, __u32 entry)
__u32 ret = 0x00;
__u16 val1, val2;
+ if (CHECK_CLUST(entry, mydata->fatsize)) {
+ printf("Error: Invalid FAT entry: 0x%08x\n", entry);
+ return ret;
+ }
+
switch (mydata->fatsize) {
case 32:
bufnum = entry / FAT32BUFSIZE;
@@ -208,6 +223,10 @@ static __u32 get_fatent(fsdata *mydata, __u32 entry)
startblock += mydata->fat_sect; /* Offset from start of disk */
+ /* Write back the fatbuf to the disk */
+ if (flush_dirty_fat_buffer(mydata) < 0)
+ return -1;
+
if (disk_read(startblock, getsize, bufptr) < 0) {
debug("Error reading FAT blocks\n");
return ret;
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 0be60ecd99..c05fc7f099 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -143,114 +143,6 @@ static int flush_dirty_fat_buffer(fsdata *mydata)
}
/*
- * Get the entry at index 'entry' in a FAT (12/16/32) table.
- * On failure 0x00 is returned.
- * When bufnum is changed, write back the previous fatbuf to the disk.
- */
-static __u32 get_fatent_value(fsdata *mydata, __u32 entry)
-{
- __u32 bufnum;
- __u32 off16, offset;
- __u32 ret = 0x00;
- __u16 val1, val2;
-
- if (CHECK_CLUST(entry, mydata->fatsize)) {
- printf("Error: Invalid FAT entry: 0x%08x\n", entry);
- return ret;
- }
-
- switch (mydata->fatsize) {
- case 32:
- bufnum = entry / FAT32BUFSIZE;
- offset = entry - bufnum * FAT32BUFSIZE;
- break;
- case 16:
- bufnum = entry / FAT16BUFSIZE;
- offset = entry - bufnum * FAT16BUFSIZE;
- break;
- case 12:
- bufnum = entry / FAT12BUFSIZE;
- offset = entry - bufnum * FAT12BUFSIZE;
- break;
-
- default:
- /* Unsupported FAT size */
- return ret;
- }
-
- debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
- mydata->fatsize, entry, entry, offset, offset);
-
- /* Read a new block of FAT entries into the cache. */
- if (bufnum != mydata->fatbufnum) {
- int getsize = FATBUFBLOCKS;
- __u8 *bufptr = mydata->fatbuf;
- __u32 fatlength = mydata->fatlength;
- __u32 startblock = bufnum * FATBUFBLOCKS;
-
- /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
- if (startblock + getsize > fatlength)
- getsize = fatlength - startblock;
-
- startblock += mydata->fat_sect; /* Offset from start of disk */
-
- /* Write back the fatbuf to the disk */
- if (flush_dirty_fat_buffer(mydata) < 0)
- return -1;
-
- if (disk_read(startblock, getsize, bufptr) < 0) {
- debug("Error reading FAT blocks\n");
- return ret;
- }
- mydata->fatbufnum = bufnum;
- }
-
- /* Get the actual entry from the table */
- switch (mydata->fatsize) {
- case 32:
- ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
- break;
- case 16:
- ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
- break;
- case 12:
- off16 = (offset * 3) / 4;
-
- switch (offset & 0x3) {
- case 0:
- ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
- ret &= 0xfff;
- break;
- case 1:
- val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
- val1 &= 0xf000;
- val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
- val2 &= 0x00ff;
- ret = (val2 << 4) | (val1 >> 12);
- break;
- case 2:
- val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
- val1 &= 0xff00;
- val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
- val2 &= 0x000f;
- ret = (val2 << 8) | (val1 >> 8);
- break;
- case 3:
- ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
- ret = (ret & 0xfff0) >> 4;
- break;
- default:
- break;
- }
- break;
- }
- debug("FAT%d: ret: %08x, entry: %08x, offset: %04x\n",
- mydata->fatsize, ret, entry, offset);
-
- return ret;
-}
-
-/*
* Set the file name information from 'name' into 'slotptr',
*/
static int str2slot(dir_slot *slotptr, const char *name, int *idx)
@@ -407,7 +299,7 @@ get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
if ((__u8 *)slotptr >= buflimit) {
if (curclust == 0)
return -1;
- curclust = get_fatent_value(mydata, dir_curclust);
+ curclust = get_fatent(mydata, dir_curclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
printf("Invalid FAT entry\n");
@@ -539,7 +431,7 @@ static __u32 determine_fatent(fsdata *mydata, __u32 entry)
__u32 next_fat, next_entry = entry + 1;
while (1) {
- next_fat = get_fatent_value(mydata, next_entry);
+ next_fat = get_fatent(mydata, next_entry);
if (next_fat == 0) {
/* found free entry, link to entry */
set_fatent_value(mydata, entry, next_entry);
@@ -625,7 +517,7 @@ static int find_empty_cluster(fsdata *mydata)
__u32 fat_val, entry = 3;
while (1) {
- fat_val = get_fatent_value(mydata, entry);
+ fat_val = get_fatent(mydata, entry);
if (fat_val == 0)
break;
entry++;
@@ -673,7 +565,7 @@ static int clear_fatent(fsdata *mydata, __u32 entry)
__u32 fat_val;
while (1) {
- fat_val = get_fatent_value(mydata, entry);
+ fat_val = get_fatent(mydata, entry);
if (fat_val != 0)
set_fatent_value(mydata, entry, 0);
else
@@ -951,7 +843,7 @@ static dir_entry *find_directory_entry(fsdata *mydata, int startsect,
return NULL;
}
- curclust = get_fatent_value(mydata, dir_curclust);
+ curclust = get_fatent(mydata, dir_curclust);
if (IS_LAST_CLUST(curclust, mydata->fatsize)) {
empty_dentptr = dentptr;
return NULL;
--
2.11.0
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