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authorAnton Staaf <robotboy@chromium.org>2011-06-13 11:40:40 +0000
committerWolfgang Denk <wd@denx.de>2011-07-28 15:36:32 +0200
commitd961c188b205bb821c16d8d9b932456d2fb79211 (patch)
tree7933e1498e8b5f38b40a484151b2a314f804f751
parent9bac35f57bd41ae3f096dee1e747b90ca80fe044 (diff)
ext2: Simplify partial sector access logic
Previously reading or writing zero full sectors (reading the end of one sector and the beginning of the next for example) was special cased and involved stack allocating a second sector buffer. This change uses the same code path for this case as well as when there are a non-zero number of full sectors to access. The result is easier to read and reduces the maximum stack used. Signed-off-by: Anton Staaf <robotboy@chromium.org> Cc: Andy Fleming <afleming@freescale.com> Acked-by: Detlev Zundel <dzu@denx.de>
-rw-r--r--fs/ext2/dev.c42
1 files changed, 15 insertions, 27 deletions
diff --git a/fs/ext2/dev.c b/fs/ext2/dev.c
index 4365b3b882..78851d0a5d 100644
--- a/fs/ext2/dev.c
+++ b/fs/ext2/dev.c
@@ -53,7 +53,7 @@ int ext2fs_set_blk_dev(block_dev_desc_t *rbdd, int part)
int ext2fs_devread(int sector, int byte_offset, int byte_len, char *buf)
{
char sec_buf[SECTOR_SIZE];
- unsigned block_len;
+ unsigned sectors;
/*
* Check partition boundaries
@@ -98,35 +98,23 @@ int ext2fs_devread(int sector, int byte_offset, int byte_len, char *buf)
sector++;
}
- if (byte_len == 0)
- return 1;
-
/* read sector aligned part */
- block_len = byte_len & ~(SECTOR_SIZE - 1);
-
- if (block_len == 0) {
- u8 p[SECTOR_SIZE];
-
- block_len = SECTOR_SIZE;
- ext2fs_block_dev_desc->block_read(ext2fs_block_dev_desc->dev,
- part_info.start + sector,
- 1, (unsigned long *)p);
- memcpy(buf, p, byte_len);
- return 1;
- }
+ sectors = byte_len / SECTOR_SIZE;
+
+ if (sectors > 0) {
+ if (ext2fs_block_dev_desc->block_read(
+ ext2fs_block_dev_desc->dev,
+ part_info.start + sector,
+ sectors,
+ (unsigned long *) buf) != sectors) {
+ printf(" ** %s read error - block\n", __func__);
+ return 0;
+ }
- if (ext2fs_block_dev_desc->block_read(ext2fs_block_dev_desc->dev,
- part_info.start + sector,
- block_len / SECTOR_SIZE,
- (unsigned long *) buf) !=
- block_len / SECTOR_SIZE) {
- printf(" ** %s read error - block\n", __func__);
- return 0;
+ buf += sectors * SECTOR_SIZE;
+ byte_len -= sectors * SECTOR_SIZE;
+ sector += sectors;
}
- block_len = byte_len & ~(SECTOR_SIZE - 1);
- buf += block_len;
- byte_len -= block_len;
- sector += block_len / SECTOR_SIZE;
if (byte_len != 0) {
/* read rest of data which are not in whole sector */