file-posix: Drop s->lock_fd

The lock_fd field is not strictly necessary because transferring locked
bytes from old fd to the new one shouldn't fail anyway. This spares the
user one fd per image.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Fam Zheng 2018-10-11 15:21:34 +08:00 committed by Kevin Wolf
parent 2996ffad3a
commit f2e3af29b7

View File

@ -142,7 +142,6 @@ do { \
typedef struct BDRVRawState {
int fd;
int lock_fd;
bool use_lock;
int type;
int open_flags;
@ -153,7 +152,7 @@ typedef struct BDRVRawState {
uint64_t shared_perm;
/* The perms bits whose corresponding bytes are already locked in
* s->lock_fd. */
* s->fd. */
uint64_t locked_perm;
uint64_t locked_shared_perm;
@ -551,18 +550,6 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
}
s->fd = fd;
s->lock_fd = -1;
if (s->use_lock) {
fd = qemu_open(filename, s->open_flags);
if (fd < 0) {
ret = -errno;
error_setg_errno(errp, errno, "Could not open '%s' for locking",
filename);
qemu_close(s->fd);
goto fail;
}
s->lock_fd = fd;
}
s->perm = 0;
s->shared_perm = BLK_PERM_ALL;
@ -823,15 +810,13 @@ static int raw_handle_perm_lock(BlockDriverState *bs,
return 0;
}
assert(s->lock_fd > 0);
switch (op) {
case RAW_PL_PREPARE:
ret = raw_apply_lock_bytes(s, s->lock_fd, s->perm | new_perm,
ret = raw_apply_lock_bytes(s, s->fd, s->perm | new_perm,
~s->shared_perm | ~new_shared,
false, errp);
if (!ret) {
ret = raw_check_lock_bytes(s->lock_fd, new_perm, new_shared, errp);
ret = raw_check_lock_bytes(s->fd, new_perm, new_shared, errp);
if (!ret) {
return 0;
}
@ -842,7 +827,7 @@ static int raw_handle_perm_lock(BlockDriverState *bs,
op = RAW_PL_ABORT;
/* fall through to unlock bytes. */
case RAW_PL_ABORT:
raw_apply_lock_bytes(s, s->lock_fd, s->perm, ~s->shared_perm,
raw_apply_lock_bytes(s, s->fd, s->perm, ~s->shared_perm,
true, &local_err);
if (local_err) {
/* Theoretically the above call only unlocks bytes and it cannot
@ -852,7 +837,7 @@ static int raw_handle_perm_lock(BlockDriverState *bs,
}
break;
case RAW_PL_COMMIT:
raw_apply_lock_bytes(s, s->lock_fd, new_perm, ~new_shared,
raw_apply_lock_bytes(s, s->fd, new_perm, ~new_shared,
true, &local_err);
if (local_err) {
/* Theoretically the above call only unlocks bytes and it cannot
@ -967,10 +952,18 @@ static void raw_reopen_commit(BDRVReopenState *state)
{
BDRVRawReopenState *rs = state->opaque;
BDRVRawState *s = state->bs->opaque;
Error *local_err = NULL;
s->check_cache_dropped = rs->check_cache_dropped;
s->open_flags = rs->open_flags;
/* Copy locks to the new fd before closing the old one. */
raw_apply_lock_bytes(NULL, rs->fd, s->locked_perm,
~s->locked_shared_perm, false, &local_err);
if (local_err) {
/* shouldn't fail in a sane host, but report it just in case. */
error_report_err(local_err);
}
qemu_close(s->fd);
s->fd = rs->fd;
@ -1963,10 +1956,6 @@ static void raw_close(BlockDriverState *bs)
qemu_close(s->fd);
s->fd = -1;
}
if (s->lock_fd >= 0) {
qemu_close(s->lock_fd);
s->lock_fd = -1;
}
}
/**