| Message ID | 20240313104327.147450-1-alexander.ivanov@virtuozzo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] block: Use LVM tools for LV block device truncation | expand |
On Wed, Mar 13, 2024 at 11:43:27AM +0100, Alexander Ivanov wrote: > If a block device is an LVM logical volume we can resize it using > standard LVM tools. > > Add a helper to detect if a device is a DM device. In raw_co_truncate() > check if the block device is DM and resize it executing lvresize. > > Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com> > --- > block/file-posix.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 61 insertions(+) > > diff --git a/block/file-posix.c b/block/file-posix.c > index 35684f7e21..5f07d98aa5 100644 > --- a/block/file-posix.c > +++ b/block/file-posix.c > @@ -2642,6 +2642,38 @@ raw_regular_truncate(BlockDriverState *bs, int fd, int64_t offset, > return raw_thread_pool_submit(handle_aiocb_truncate, &acb); > } > static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset, > bool exact, PreallocMode prealloc, > BdrvRequestFlags flags, Error **errp) > @@ -2670,6 +2702,35 @@ static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset, > if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) { > int64_t cur_length = raw_getlength(bs); > > + /* > + * Try to resize an LVM device using LVM tools. > + */ > + if (device_is_dm(&st) && offset > 0) { > + int spawn_flags = G_SPAWN_SEARCH_PATH | G_SPAWN_STDOUT_TO_DEV_NULL; > + int status; > + bool success; > + char *err; > + GError *gerr = NULL; > + g_autofree char *size_str = g_strdup_printf("%ldB", offset); offset is 64-bit, but '%ld' is not guaranteed to be 64-bit. I expect this will break on 32-bit platforms. Try PRId64 instead. > + const char *cmd[] = {"lvresize", "-f", "-L", > + size_str, bs->filename, NULL}; > + > + success = g_spawn_sync(NULL, (gchar **)cmd, NULL, spawn_flags, > + NULL, NULL, NULL, &err, &status, &gerr); > + > + if (success && WEXITSTATUS(status) == 0) { > + return 0; > + } We should probably check 'g_spawn_check_wait_status' rather than WEXITSTATUS, as this then gives us further eror message details that.... > + > + if (!success) { > + error_setg(errp, "lvresize execution error: %s", gerr->message); > + } else { > + error_setg(errp, "%s", err); ...we would also include here, such as the exit code or terminal signal. > + } > + > + return -EINVAL; > + } > + > if (offset != cur_length && exact) { > error_setg(errp, "Cannot resize device files"); > return -ENOTSUP; > -- > 2.40.1 > > With regards, Daniel
On 3/14/24 13:44, Daniel P. Berrangé wrote: > On Wed, Mar 13, 2024 at 11:43:27AM +0100, Alexander Ivanov wrote: >> If a block device is an LVM logical volume we can resize it using >> standard LVM tools. >> >> Add a helper to detect if a device is a DM device. In raw_co_truncate() >> check if the block device is DM and resize it executing lvresize. >> >> Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com> >> --- >> block/file-posix.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 61 insertions(+) >> >> diff --git a/block/file-posix.c b/block/file-posix.c >> index 35684f7e21..5f07d98aa5 100644 >> --- a/block/file-posix.c >> +++ b/block/file-posix.c >> @@ -2642,6 +2642,38 @@ raw_regular_truncate(BlockDriverState *bs, int fd, int64_t offset, >> return raw_thread_pool_submit(handle_aiocb_truncate, &acb); >> } >> static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset, >> bool exact, PreallocMode prealloc, >> BdrvRequestFlags flags, Error **errp) >> @@ -2670,6 +2702,35 @@ static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset, >> if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) { >> int64_t cur_length = raw_getlength(bs); >> >> + /* >> + * Try to resize an LVM device using LVM tools. >> + */ >> + if (device_is_dm(&st) && offset > 0) { >> + int spawn_flags = G_SPAWN_SEARCH_PATH | G_SPAWN_STDOUT_TO_DEV_NULL; >> + int status; >> + bool success; >> + char *err; >> + GError *gerr = NULL; >> + g_autofree char *size_str = g_strdup_printf("%ldB", offset); > offset is 64-bit, but '%ld' is not guaranteed to be 64-bit. I expect > this will break on 32-bit platforms. Try PRId64 instead. > >> + const char *cmd[] = {"lvresize", "-f", "-L", >> + size_str, bs->filename, NULL}; >> + >> + success = g_spawn_sync(NULL, (gchar **)cmd, NULL, spawn_flags, >> + NULL, NULL, NULL, &err, &status, &gerr); >> + >> + if (success && WEXITSTATUS(status) == 0) { >> + return 0; >> + } > We should probably check 'g_spawn_check_wait_status' rather than > WEXITSTATUS, as this then gives us further eror message details > that.... Thank you. I think it would be better to use 'g_spawn_check_exit_status' because there is no 'g_spawn_check_wait_status' in glib before 2.70 and even in 2.78 it leads to 'g_spawn_check_wait_status is deprecated: Not available before 2.70' error. > >> + >> + if (!success) { >> + error_setg(errp, "lvresize execution error: %s", gerr->message); >> + } else { >> + error_setg(errp, "%s", err); > ...we would also include here, such as the exit code or terminal > signal. > >> + } >> + >> + return -EINVAL; >> + } >> + >> if (offset != cur_length && exact) { >> error_setg(errp, "Cannot resize device files"); >> return -ENOTSUP; >> -- >> 2.40.1 >> >> > With regards, > Daniel
On Thu, Mar 14, 2024 at 06:25:00PM +0100, Alexander Ivanov wrote: > > > On 3/14/24 13:44, Daniel P. Berrangé wrote: > > On Wed, Mar 13, 2024 at 11:43:27AM +0100, Alexander Ivanov wrote: > > > If a block device is an LVM logical volume we can resize it using > > > standard LVM tools. > > > > > > Add a helper to detect if a device is a DM device. In raw_co_truncate() > > > check if the block device is DM and resize it executing lvresize. > > > > > > Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com> > > > --- > > > block/file-posix.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 61 insertions(+) > > > > > > diff --git a/block/file-posix.c b/block/file-posix.c > > > index 35684f7e21..5f07d98aa5 100644 > > > --- a/block/file-posix.c > > > +++ b/block/file-posix.c > > > @@ -2642,6 +2642,38 @@ raw_regular_truncate(BlockDriverState *bs, int fd, int64_t offset, > > > return raw_thread_pool_submit(handle_aiocb_truncate, &acb); > > > } > > > static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset, > > > bool exact, PreallocMode prealloc, > > > BdrvRequestFlags flags, Error **errp) > > > @@ -2670,6 +2702,35 @@ static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset, > > > if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) { > > > int64_t cur_length = raw_getlength(bs); > > > + /* > > > + * Try to resize an LVM device using LVM tools. > > > + */ > > > + if (device_is_dm(&st) && offset > 0) { > > > + int spawn_flags = G_SPAWN_SEARCH_PATH | G_SPAWN_STDOUT_TO_DEV_NULL; > > > + int status; > > > + bool success; > > > + char *err; > > > + GError *gerr = NULL; > > > + g_autofree char *size_str = g_strdup_printf("%ldB", offset); > > offset is 64-bit, but '%ld' is not guaranteed to be 64-bit. I expect > > this will break on 32-bit platforms. Try PRId64 instead. > > > > > + const char *cmd[] = {"lvresize", "-f", "-L", > > > + size_str, bs->filename, NULL}; > > > + > > > + success = g_spawn_sync(NULL, (gchar **)cmd, NULL, spawn_flags, > > > + NULL, NULL, NULL, &err, &status, &gerr); > > > + > > > + if (success && WEXITSTATUS(status) == 0) { > > > + return 0; > > > + } > > We should probably check 'g_spawn_check_wait_status' rather than > > WEXITSTATUS, as this then gives us further eror message details > > that.... > Thank you. > I think it would be better to use 'g_spawn_check_exit_status' because there > is no > 'g_spawn_check_wait_status' in glib before 2.70 and even in 2.78 it leads to > 'g_spawn_check_wait_status is deprecated: Not available before 2.70' error. Ah yes, well spotted. With regards, Daniel
diff --git a/block/file-posix.c b/block/file-posix.c index 35684f7e21..5f07d98aa5 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -2642,6 +2642,38 @@ raw_regular_truncate(BlockDriverState *bs, int fd, int64_t offset, return raw_thread_pool_submit(handle_aiocb_truncate, &acb); } +static bool device_is_dm(struct stat *st) +{ + unsigned int maj, maj2; + char line[32], devname[16]; + bool ret = false; + FILE *f; + + if (!S_ISBLK(st->st_mode)) { + return false; + } + + f = fopen("/proc/devices", "r"); + if (!f) { + return false; + } + + maj = major(st->st_rdev); + + while (fgets(line, sizeof(line), f)) { + if (sscanf(line, "%u %15s", &maj2, devname) != 2) { + continue; + } + if (strcmp(devname, "device-mapper") == 0) { + ret = (maj == maj2); + break; + } + } + + fclose(f); + return ret; +} + static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset, bool exact, PreallocMode prealloc, BdrvRequestFlags flags, Error **errp) @@ -2670,6 +2702,35 @@ static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset, if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) { int64_t cur_length = raw_getlength(bs); + /* + * Try to resize an LVM device using LVM tools. + */ + if (device_is_dm(&st) && offset > 0) { + int spawn_flags = G_SPAWN_SEARCH_PATH | G_SPAWN_STDOUT_TO_DEV_NULL; + int status; + bool success; + char *err; + GError *gerr = NULL; + g_autofree char *size_str = g_strdup_printf("%ldB", offset); + const char *cmd[] = {"lvresize", "-f", "-L", + size_str, bs->filename, NULL}; + + success = g_spawn_sync(NULL, (gchar **)cmd, NULL, spawn_flags, + NULL, NULL, NULL, &err, &status, &gerr); + + if (success && WEXITSTATUS(status) == 0) { + return 0; + } + + if (!success) { + error_setg(errp, "lvresize execution error: %s", gerr->message); + } else { + error_setg(errp, "%s", err); + } + + return -EINVAL; + } + if (offset != cur_length && exact) { error_setg(errp, "Cannot resize device files"); return -ENOTSUP;
If a block device is an LVM logical volume we can resize it using standard LVM tools. Add a helper to detect if a device is a DM device. In raw_co_truncate() check if the block device is DM and resize it executing lvresize. Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com> --- block/file-posix.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+)