cmd_dump: Use buffered IO for reading device metadata

We're reading device metadat in mostly sequential order - buffered IO
will be faster than O_DIRECT.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This commit is contained in:
Kent Overstreet 2022-06-18 18:33:25 -04:00
parent a232478f35
commit 03b8098d37
3 changed files with 7 additions and 9 deletions

View File

@ -99,7 +99,7 @@ static void dump_one_device(struct bch_fs *c, struct bch_dev *ca, int fd,
bch2_trans_exit(&trans);
}
qcow2_write_image(ca->disk_sb.bdev->bd_fd, fd, &data,
qcow2_write_image(ca->disk_sb.bdev->bd_buffered_fd, fd, &data,
max_t(unsigned, btree_bytes(c) / 8, block_bytes(c)));
darray_exit(&data);
}

View File

@ -40,6 +40,7 @@ struct block_device {
struct gendisk __bd_disk;
int bd_fd;
int bd_sync_fd;
int bd_buffered_fd;
};
#define bdev_kobj(_bdev) (&((_bdev)->kobj))

View File

@ -168,7 +168,7 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
void *holder)
{
struct block_device *bdev;
int fd, sync_fd, flags = O_DIRECT;
int fd, sync_fd, buffered_fd, flags = 0;
if ((mode & (FMODE_READ|FMODE_WRITE)) == (FMODE_READ|FMODE_WRITE))
flags = O_RDWR;
@ -183,16 +183,12 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
flags |= O_EXCL;
#endif
fd = open(path, flags);
fd = open(path, flags|O_DIRECT);
if (fd < 0)
return ERR_PTR(-errno);
sync_fd = open(path, flags|O_SYNC);
if (sync_fd < 0) {
assert(0);
close(fd);
return ERR_PTR(-errno);
}
sync_fd = xopen(path, flags|O_DIRECT|O_SYNC);
buffered_fd = xopen(path, flags);
bdev = malloc(sizeof(*bdev));
memset(bdev, 0, sizeof(*bdev));
@ -203,6 +199,7 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
bdev->bd_dev = xfstat(fd).st_rdev;
bdev->bd_fd = fd;
bdev->bd_sync_fd = sync_fd;
bdev->bd_buffered_fd = buffered_fd;
bdev->bd_holder = holder;
bdev->bd_disk = &bdev->__bd_disk;
bdev->bd_disk->bdi = &bdev->bd_disk->__bdi;