diff options
| author | Christophe Vu-Brugier <christophe.vu-brugier@seagate.com> | 2021-10-12 15:49:08 +0200 |
|---|---|---|
| committer | Christophe Vu-Brugier <christophe.vu-brugier@seagate.com> | 2021-10-12 15:49:08 +0200 |
| commit | 5c22bb8620b86e37cded363719b1cf80afd9c880 (patch) | |
| tree | 79c10bcc184e9964295412b4fced1c1ccfda5b32 | |
| parent | ac05554b21e5b1a5cb8412c9f64ec193c4311f77 (diff) | |
| download | exfatprogs-5c22bb8620b86e37cded363719b1cf80afd9c880.tar.gz | |
mkfs: replace lseek() + write() with pwrite()
This reduces the number of system calls issued and may improve
robustness because the return value of lseek() was never checked.
Signed-off-by: Christophe Vu-Brugier <christophe.vu-brugier@seagate.com>
| -rw-r--r-- | lib/libexfat.c | 6 | ||||
| -rw-r--r-- | mkfs/mkfs.c | 10 | ||||
| -rw-r--r-- | mkfs/upcase.c | 3 |
3 files changed, 7 insertions, 12 deletions
diff --git a/lib/libexfat.c b/lib/libexfat.c index c54a7c8..c1c9b03 100644 --- a/lib/libexfat.c +++ b/lib/libexfat.c @@ -475,8 +475,7 @@ int exfat_read_sector(struct exfat_blk_dev *bd, void *buf, unsigned int sec_off) int ret; unsigned long long offset = sec_off * bd->sector_size; - lseek(bd->dev_fd, offset, SEEK_SET); - ret = read(bd->dev_fd, buf, bd->sector_size); + ret = pread(bd->dev_fd, buf, bd->sector_size, offset); if (ret < 0) { exfat_err("read failed, sec_off : %u\n", sec_off); return -1; @@ -490,8 +489,7 @@ int exfat_write_sector(struct exfat_blk_dev *bd, void *buf, int bytes; unsigned long long offset = sec_off * bd->sector_size; - lseek(bd->dev_fd, offset, SEEK_SET); - bytes = write(bd->dev_fd, buf, bd->sector_size); + bytes = pwrite(bd->dev_fd, buf, bd->sector_size, offset); if (bytes != (int)bd->sector_size) { exfat_err("write failed, sec_off : %u, bytes : %d\n", sec_off, bytes); diff --git a/mkfs/mkfs.c b/mkfs/mkfs.c index ded1e20..b663cb8 100644 --- a/mkfs/mkfs.c +++ b/mkfs/mkfs.c @@ -235,9 +235,9 @@ static int write_fat_entry(int fd, __le32 clu, unsigned long long offset) { int nbyte; + off_t fat_entry_offset = finfo.fat_byte_off + (offset * sizeof(__le32)); - lseek(fd, finfo.fat_byte_off + (offset * sizeof(__le32)), SEEK_SET); - nbyte = write(fd, (__u8 *) &clu, sizeof(__le32)); + nbyte = pwrite(fd, (__u8 *) &clu, sizeof(__le32), fat_entry_offset); if (nbyte != sizeof(int)) { exfat_err("write failed, offset : %llu, clu : %x\n", offset, clu); @@ -321,8 +321,7 @@ static int exfat_create_bitmap(struct exfat_blk_dev *bd) for (i = 0; i < finfo.used_clu_cnt - EXFAT_FIRST_CLUSTER; i++) exfat_set_bit(bd, bitmap, i); - lseek(bd->dev_fd, finfo.bitmap_byte_off, SEEK_SET); - nbytes = write(bd->dev_fd, bitmap, finfo.bitmap_byte_len); + nbytes = pwrite(bd->dev_fd, bitmap, finfo.bitmap_byte_len, finfo.bitmap_byte_off); if (nbytes != finfo.bitmap_byte_len) { exfat_err("write failed, nbytes : %d, bitmap_len : %d\n", nbytes, finfo.bitmap_byte_len); @@ -359,8 +358,7 @@ static int exfat_create_root_dir(struct exfat_blk_dev *bd, ed[2].upcase_start_clu = cpu_to_le32(finfo.ut_start_clu); ed[2].upcase_size = cpu_to_le64(EXFAT_UPCASE_TABLE_SIZE); - lseek(bd->dev_fd, finfo.root_byte_off, SEEK_SET); - nbytes = write(bd->dev_fd, ed, dentries_len); + nbytes = pwrite(bd->dev_fd, ed, dentries_len, finfo.root_byte_off); if (nbytes != dentries_len) { exfat_err("write failed, nbytes : %d, dentries_len : %d\n", nbytes, dentries_len); diff --git a/mkfs/upcase.c b/mkfs/upcase.c index 8d5ef1a..f86fa23 100644 --- a/mkfs/upcase.c +++ b/mkfs/upcase.c @@ -506,8 +506,7 @@ int exfat_create_upcase_table(struct exfat_blk_dev *bd) { int nbytes; - lseek(bd->dev_fd, finfo.ut_byte_off, SEEK_SET); - nbytes = write(bd->dev_fd, upcase_table, EXFAT_UPCASE_TABLE_SIZE); + nbytes = pwrite(bd->dev_fd, upcase_table, EXFAT_UPCASE_TABLE_SIZE, finfo.ut_byte_off); if (nbytes != EXFAT_UPCASE_TABLE_SIZE) return -1; |