[libvirt] [PATCH v2 2/7] virlockspace: Introduce VIR_LOCK_SPACE_ACQUIRE_WAIT
This flag modifies the way the lock is acquired. It waits for the
lock to be set instead of usual set-or-fail logic that happens
without this flag.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/util/virlockspace.c | 14 ++++++++++----
src/util/virlockspace.h | 1 +
2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/src/util/virlockspace.c b/src/util/virlockspace.c
index 60bfef4c5f..d75a6d4a6e 100644
--- a/src/util/virlockspace.c
+++ b/src/util/virlockspace.c
@@ -122,6 +122,7 @@ virLockSpaceResourceNew(virLockSpacePtr lockspace,
{
virLockSpaceResourcePtr res;
bool shared = !!(flags & VIR_LOCK_SPACE_ACQUIRE_SHARED);
+ bool waitForLock = !!(flags & VIR_LOCK_SPACE_ACQUIRE_WAIT);
if (VIR_ALLOC(res) < 0)
return NULL;
@@ -159,7 +160,7 @@ virLockSpaceResourceNew(virLockSpacePtr lockspace,
goto error;
}
- if (virFileLock(res->fd, shared, start, len, false) < 0) {
+ if (virFileLock(res->fd, shared, start, len, waitForLock) < 0) {
if (errno == EACCES || errno == EAGAIN) {
virReportError(VIR_ERR_RESOURCE_BUSY,
_("Lockspace resource '%s' is
locked"),
@@ -206,7 +207,7 @@ virLockSpaceResourceNew(virLockSpacePtr lockspace,
goto error;
}
- if (virFileLock(res->fd, shared, start, len, false) < 0) {
+ if (virFileLock(res->fd, shared, start, len, waitForLock) < 0) {
if (errno == EACCES || errno == EAGAIN) {
virReportError(VIR_ERR_RESOURCE_BUSY,
_("Lockspace resource '%s' is locked"),
@@ -625,11 +626,16 @@ int virLockSpaceAcquireResource(virLockSpacePtr lockspace,
lockspace, resname, flags, (unsigned long long)owner);
virCheckFlags(VIR_LOCK_SPACE_ACQUIRE_SHARED |
- VIR_LOCK_SPACE_ACQUIRE_AUTOCREATE, -1);
+ VIR_LOCK_SPACE_ACQUIRE_AUTOCREATE |
+ VIR_LOCK_SPACE_ACQUIRE_WAIT, -1);
+
+ VIR_EXCLUSIVE_FLAGS_RET(VIR_LOCK_SPACE_ACQUIRE_WAIT,
+ VIR_LOCK_SPACE_ACQUIRE_SHARED, -1);
virMutexLock(&lockspace->lock);
- if ((res = virHashLookup(lockspace->resources, resname))) {
+ if (!(flags & VIR_LOCK_SPACE_ACQUIRE_WAIT) &&
+ (res = virHashLookup(lockspace->resources, resname))) {
if ((res->flags & VIR_LOCK_SPACE_ACQUIRE_SHARED) &&
(flags & VIR_LOCK_SPACE_ACQUIRE_SHARED)) {
diff --git a/src/util/virlockspace.h b/src/util/virlockspace.h
index 24f2c89be6..bfaed34d5b 100644
--- a/src/util/virlockspace.h
+++ b/src/util/virlockspace.h
@@ -47,6 +47,7 @@ int virLockSpaceDeleteResource(virLockSpacePtr lockspace,
typedef enum {
VIR_LOCK_SPACE_ACQUIRE_SHARED = (1 << 0),
VIR_LOCK_SPACE_ACQUIRE_AUTOCREATE = (1 << 1),
+ VIR_LOCK_SPACE_ACQUIRE_WAIT = (1 << 2),
} virLockSpaceAcquireFlags;
int virLockSpaceAcquireResource(virLockSpacePtr lockspace,
--
2.16.4