[libvirt] [PATCH] util: allow creation of file with virFileWriteStr

Making this change will allow the future patches to use virFileWriteStr to create a file, rather than its current limitation of only working on pre-existing files. * src/util/util.h (virFileWriteStr): Alter signature. * src/util/util.c (virFileWriteStr): Allow file creation. * src/network/bridge_driver.c (networkEnableIpForwarding) (networkDisableIPV6): Adjust clients. * src/node_device/node_device_driver.c (nodeDeviceVportCreateDelete): Likewise. * src/util/cgroup.c (virCgroupSetValueStr): Likewise. * src/util/pci.c (pciBindDeviceToStub, pciUnBindDeviceFromStub): Likewise. Based on a report from Jean-Baptiste Rouault. --- How does this look? Admittedly, all existing uses were okay with a mode parameter of 0; and I haven't yet seen your patch that would use a non-zero mode, but this still makes more sense to me. Oh, and VIR_FORCE_CLOSE preserves errno, so I was able to simplify virFileWriteStr in the process. src/network/bridge_driver.c | 8 ++++---- src/node_device/node_device_driver.c | 2 +- src/util/cgroup.c | 2 +- src/util/pci.c | 16 ++++++++-------- src/util/util.c | 13 ++++++++----- src/util/util.h | 3 ++- 6 files changed, 24 insertions(+), 20 deletions(-) diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index 54890f9..62639e4 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -1024,7 +1024,7 @@ networkReloadIptablesRules(struct network_driver *driver) static int networkEnableIpForwarding(void) { - return virFileWriteStr("/proc/sys/net/ipv4/ip_forward", "1\n"); + return virFileWriteStr("/proc/sys/net/ipv4/ip_forward", "1\n", 0); } #define SYSCTL_PATH "/proc/sys" @@ -1045,7 +1045,7 @@ static int networkDisableIPV6(virNetworkObjPtr network) goto cleanup; } - if (virFileWriteStr(field, "1") < 0) { + if (virFileWriteStr(field, "1", 0) < 0) { virReportSystemError(errno, _("cannot enable %s"), field); goto cleanup; @@ -1057,7 +1057,7 @@ static int networkDisableIPV6(virNetworkObjPtr network) goto cleanup; } - if (virFileWriteStr(field, "0") < 0) { + if (virFileWriteStr(field, "0", 0) < 0) { virReportSystemError(errno, _("cannot disable %s"), field); goto cleanup; @@ -1069,7 +1069,7 @@ static int networkDisableIPV6(virNetworkObjPtr network) goto cleanup; } - if (virFileWriteStr(field, "1") < 0) { + if (virFileWriteStr(field, "1", 0) < 0) { virReportSystemError(errno, _("cannot enable %s"), field); goto cleanup; diff --git a/src/node_device/node_device_driver.c b/src/node_device/node_device_driver.c index 448cfd3..a6c6042 100644 --- a/src/node_device/node_device_driver.c +++ b/src/node_device/node_device_driver.c @@ -454,7 +454,7 @@ nodeDeviceVportCreateDelete(const int parent_host, goto cleanup; } - if (virFileWriteStr(operation_path, vport_name) == -1) { + if (virFileWriteStr(operation_path, vport_name, 0) == -1) { virReportSystemError(errno, _("Write of '%s' to '%s' during " "vport create/delete failed"), diff --git a/src/util/cgroup.c b/src/util/cgroup.c index 2758a8f..3ba6325 100644 --- a/src/util/cgroup.c +++ b/src/util/cgroup.c @@ -288,7 +288,7 @@ static int virCgroupSetValueStr(virCgroupPtr group, return rc; VIR_DEBUG("Set value '%s' to '%s'", keypath, value); - rc = virFileWriteStr(keypath, value); + rc = virFileWriteStr(keypath, value, 0); if (rc < 0) { DEBUG("Failed to write value '%s': %m", value); rc = -errno; diff --git a/src/util/pci.c b/src/util/pci.c index d38cefa..095ad3f 100644 --- a/src/util/pci.c +++ b/src/util/pci.c @@ -849,7 +849,7 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver) * bound by the stub. */ pciDriverFile(path, sizeof(path), driver, "new_id"); - if (virFileWriteStr(path, dev->id) < 0) { + if (virFileWriteStr(path, dev->id, 0) < 0) { virReportSystemError(errno, _("Failed to add PCI device ID '%s' to %s"), dev->id, driver); @@ -862,7 +862,7 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver) * your root filesystem. */ pciDeviceFile(path, sizeof(path), dev->name, "driver/unbind"); - if (virFileExists(path) && virFileWriteStr(path, dev->name) < 0) { + if (virFileExists(path) && virFileWriteStr(path, dev->name, 0) < 0) { virReportSystemError(errno, _("Failed to unbind PCI device '%s'"), dev->name); return -1; @@ -875,7 +875,7 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver) if (!virFileLinkPointsTo(path, drvdir)) { /* Xen's pciback.ko wants you to use new_slot first */ pciDriverFile(path, sizeof(path), driver, "new_slot"); - if (virFileExists(path) && virFileWriteStr(path, dev->name) < 0) { + if (virFileExists(path) && virFileWriteStr(path, dev->name, 0) < 0) { virReportSystemError(errno, _("Failed to add slot for PCI device '%s' to %s"), dev->name, driver); @@ -883,7 +883,7 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver) } pciDriverFile(path, sizeof(path), driver, "bind"); - if (virFileWriteStr(path, dev->name) < 0) { + if (virFileWriteStr(path, dev->name, 0) < 0) { virReportSystemError(errno, _("Failed to bind PCI device '%s' to %s"), dev->name, driver); @@ -895,7 +895,7 @@ pciBindDeviceToStub(pciDevice *dev, const char *driver) * ID table so that 'drivers_probe' works below. */ pciDriverFile(path, sizeof(path), driver, "remove_id"); - if (virFileExists(path) && virFileWriteStr(path, dev->id) < 0) { + if (virFileExists(path) && virFileWriteStr(path, dev->id, 0) < 0) { virReportSystemError(errno, _("Failed to remove PCI ID '%s' from %s"), dev->id, driver); @@ -936,7 +936,7 @@ pciUnBindDeviceFromStub(pciDevice *dev, const char *driver) pciDeviceFile(path, sizeof(path), dev->name, "driver"); if (virFileExists(drvdir) && virFileLinkPointsTo(path, drvdir)) { pciDriverFile(path, sizeof(path), driver, "unbind"); - if (virFileWriteStr(path, dev->name) < 0) { + if (virFileWriteStr(path, dev->name, 0) < 0) { virReportSystemError(errno, _("Failed to bind PCI device '%s' to %s"), dev->name, driver); @@ -946,7 +946,7 @@ pciUnBindDeviceFromStub(pciDevice *dev, const char *driver) /* Xen's pciback.ko wants you to use remove_slot on the specific device */ pciDriverFile(path, sizeof(path), driver, "remove_slot"); - if (virFileExists(path) && virFileWriteStr(path, dev->name) < 0) { + if (virFileExists(path) && virFileWriteStr(path, dev->name, 0) < 0) { virReportSystemError(errno, _("Failed to remove slot for PCI device '%s' to %s"), dev->name, driver); @@ -961,7 +961,7 @@ pciUnBindDeviceFromStub(pciDevice *dev, const char *driver) */ pciDriverFile(path, sizeof(path), driver, "remove_id"); if (!virFileExists(drvdir) || virFileExists(path)) { - if (virFileWriteStr(PCI_SYSFS "drivers_probe", dev->name) < 0) { + if (virFileWriteStr(PCI_SYSFS "drivers_probe", dev->name, 0) < 0) { virReportSystemError(errno, _("Failed to trigger a re-probe for PCI device '%s'"), dev->name); diff --git a/src/util/util.c b/src/util/util.c index f6050de..79ca5d3 100644 --- a/src/util/util.c +++ b/src/util/util.c @@ -1125,20 +1125,23 @@ int virFileReadAll(const char *path, int maxlen, char **buf) return len; } -/* Truncate @path and write @str to it. +/* Truncate @path and write @str to it. If @mode is 0, ensure that + @path exists; otherwise, use @mode if @path must be created. Return 0 for success, nonzero for failure. Be careful to preserve any errno value upon failure. */ -int virFileWriteStr(const char *path, const char *str) +int virFileWriteStr(const char *path, const char *str, mode_t mode) { int fd; - if ((fd = open(path, O_WRONLY|O_TRUNC)) == -1) + if (mode) + fd = open(path, O_WRONLY|O_TRUNC|O_CREAT, mode); + else + fd = open(path, O_WRONLY|O_TRUNC); + if (fd == -1) return -1; if (safewrite(fd, str, strlen(str)) < 0) { - int saved_errno = errno; VIR_FORCE_CLOSE(fd); - errno = saved_errno; return -1; } diff --git a/src/util/util.h b/src/util/util.h index deaf8bb..ef4fc13 100644 --- a/src/util/util.h +++ b/src/util/util.h @@ -97,7 +97,8 @@ int virFileReadLimFD(int fd, int maxlen, char **buf) ATTRIBUTE_RETURN_CHECK; int virFileReadAll(const char *path, int maxlen, char **buf) ATTRIBUTE_RETURN_CHECK; -int virFileWriteStr(const char *path, const char *str) ATTRIBUTE_RETURN_CHECK; +int virFileWriteStr(const char *path, const char *str, mode_t mode) + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_RETURN_CHECK; int virFileMatchesNameSuffix(const char *file, const char *name, -- 1.7.3.2