From: Fam Zheng <famz@redhat.com>
To: qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Max Reitz <mreitz@redhat.com>,
qemu-block@nongnu.org
Subject: [Qemu-devel] [PATCH v5 2/3] file-posix: Drop s->lock_fd
Date: Thu, 11 Oct 2018 15:21:34 +0800 [thread overview]
Message-ID: <20181011072135.588-3-famz@redhat.com> (raw)
In-Reply-To: <20181011072135.588-1-famz@redhat.com>
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>
---
block/file-posix.c | 37 +++++++++++++------------------------
1 file changed, 13 insertions(+), 24 deletions(-)
diff --git a/block/file-posix.c b/block/file-posix.c
index cf5eb98caa..d493357b89 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -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;
@@ -542,18 +541,6 @@ 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;
@@ -814,15 +801,13 @@ 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;
}
@@ -833,7 +818,7 @@ 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
@@ -843,7 +828,7 @@ 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
@@ -960,10 +945,18 @@ 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;
@@ -1956,10 +1949,6 @@ 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;
- }
}
/**
--
2.17.1
next prev parent reply other threads:[~2018-10-11 7:21 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-11 7:21 [Qemu-devel] [PATCH v5 0/3] file-posix: Simplifications on image locking Fam Zheng
2018-10-11 7:21 ` [Qemu-devel] [PATCH v5 1/3] file-posix: Skip effectiveless OFD lock operations Fam Zheng
2018-10-11 7:21 ` Fam Zheng [this message]
2018-11-14 13:54 ` [Qemu-devel] [Qemu-block] [PATCH v5 2/3] file-posix: Drop s->lock_fd Alberto Garcia
2018-11-16 13:34 ` Max Reitz
2018-11-16 13:58 ` Alberto Garcia
2018-11-16 14:02 ` Max Reitz
2018-11-16 14:16 ` Max Reitz
2018-10-11 7:21 ` [Qemu-devel] [PATCH v5 3/3] tests: Add unit tests for image locking Fam Zheng
2018-11-08 3:16 ` [Qemu-devel] [PATCH v5 0/3] file-posix: Simplifications on " Fam Zheng
2018-11-08 9:26 ` Kevin Wolf
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