From: Alasdair G Kergon Commit outstanding metadata before returning the status for a dm thin pool so that the numbers reported are as up-to-date as possible. The commit is not performed if the device is suspended or if the DM_NOFLUSH_FLAG is supplied by userspace and passed to the target through a new 'status_flags' parameter in the target's dm_status_fn. The userspace dmsetup tool will support the --noflush flag with the 'dmsetup status' and 'dmsetup wait' commands from version 1.02.76 onwards. Tested-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-crypt.c | 2 +- drivers/md/dm-delay.c | 2 +- drivers/md/dm-flakey.c | 2 +- drivers/md/dm-ioctl.c | 5 ++++- drivers/md/dm-linear.c | 2 +- drivers/md/dm-mpath.c | 2 +- drivers/md/dm-raid.c | 2 +- drivers/md/dm-raid1.c | 2 +- drivers/md/dm-snap.c | 6 +++--- drivers/md/dm-stripe.c | 4 ++-- drivers/md/dm-thin.c | 9 +++++++-- drivers/md/dm-verity.c | 2 +- drivers/md/dm.h | 5 +++++ include/linux/device-mapper.h | 2 +- include/linux/dm-ioctl.h | 8 +++++--- 15 files changed, 35 insertions(+), 20 deletions(-) Index: linux/drivers/md/dm-crypt.c =================================================================== --- linux.orig/drivers/md/dm-crypt.c +++ linux/drivers/md/dm-crypt.c @@ -1733,7 +1733,7 @@ static int crypt_map(struct dm_target *t } static int crypt_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) + unsigned status_flags, char *result, unsigned maxlen) { struct crypt_config *cc = ti->private; unsigned int sz = 0; Index: linux/drivers/md/dm-delay.c =================================================================== --- linux.orig/drivers/md/dm-delay.c +++ linux/drivers/md/dm-delay.c @@ -295,7 +295,7 @@ static int delay_map(struct dm_target *t } static int delay_status(struct dm_target *ti, status_type_t type, - char *result, unsigned maxlen) + unsigned status_flags, char *result, unsigned maxlen) { struct delay_c *dc = ti->private; int sz = 0; Index: linux/drivers/md/dm-flakey.c =================================================================== --- linux.orig/drivers/md/dm-flakey.c +++ linux/drivers/md/dm-flakey.c @@ -333,7 +333,7 @@ static int flakey_end_io(struct dm_targe } static int flakey_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) + unsigned status_flags, char *result, unsigned maxlen) { unsigned sz = 0; struct flakey_c *fc = ti->private; Index: linux/drivers/md/dm-ioctl.c =================================================================== --- linux.orig/drivers/md/dm-ioctl.c +++ linux/drivers/md/dm-ioctl.c @@ -1054,6 +1054,7 @@ static void retrieve_status(struct dm_ta char *outbuf, *outptr; status_type_t type; size_t remaining, len, used = 0; + unsigned status_flags = 0; outptr = outbuf = get_result_buffer(param, param_size, &len); @@ -1090,7 +1091,9 @@ static void retrieve_status(struct dm_ta /* Get the status/table string from the target driver */ if (ti->type->status) { - if (ti->type->status(ti, type, outptr, remaining)) { + if (param->flags & DM_NOFLUSH_FLAG) + status_flags |= DM_STATUS_NOFLUSH_FLAG; + if (ti->type->status(ti, type, status_flags, outptr, remaining)) { param->flags |= DM_BUFFER_FULL_FLAG; break; } Index: linux/drivers/md/dm-linear.c =================================================================== --- linux.orig/drivers/md/dm-linear.c +++ linux/drivers/md/dm-linear.c @@ -96,7 +96,7 @@ static int linear_map(struct dm_target * } static int linear_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) + unsigned status_flags, char *result, unsigned maxlen) { struct linear_c *lc = (struct linear_c *) ti->private; Index: linux/drivers/md/dm-mpath.c =================================================================== --- linux.orig/drivers/md/dm-mpath.c +++ linux/drivers/md/dm-mpath.c @@ -1378,7 +1378,7 @@ static void multipath_resume(struct dm_t * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ */ static int multipath_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) + unsigned status_flags, char *result, unsigned maxlen) { int sz = 0; unsigned long flags; Index: linux/drivers/md/dm-raid.c =================================================================== --- linux.orig/drivers/md/dm-raid.c +++ linux/drivers/md/dm-raid.c @@ -1081,7 +1081,7 @@ static int raid_map(struct dm_target *ti } static int raid_status(struct dm_target *ti, status_type_t type, - char *result, unsigned maxlen) + unsigned status_flags, char *result, unsigned maxlen) { struct raid_set *rs = ti->private; unsigned raid_param_cnt = 1; /* at least 1 for chunksize */ Index: linux/drivers/md/dm-raid1.c =================================================================== --- linux.orig/drivers/md/dm-raid1.c +++ linux/drivers/md/dm-raid1.c @@ -1367,7 +1367,7 @@ static char device_status_char(struct mi static int mirror_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) + unsigned status_flags, char *result, unsigned maxlen) { unsigned int m, sz = 0; struct mirror_set *ms = (struct mirror_set *) ti->private; Index: linux/drivers/md/dm-snap.c =================================================================== --- linux.orig/drivers/md/dm-snap.c +++ linux/drivers/md/dm-snap.c @@ -1849,7 +1849,7 @@ static void snapshot_merge_resume(struct } static int snapshot_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) + unsigned status_flags, char *result, unsigned maxlen) { unsigned sz = 0; struct dm_snapshot *snap = ti->private; @@ -2151,8 +2151,8 @@ static void origin_resume(struct dm_targ ti->max_io_len = get_origin_minimum_chunksize(dev->bdev); } -static int origin_status(struct dm_target *ti, status_type_t type, char *result, - unsigned int maxlen) +static int origin_status(struct dm_target *ti, status_type_t type, + unsigned status_flags, char *result, unsigned maxlen) { struct dm_dev *dev = ti->private; Index: linux/drivers/md/dm-stripe.c =================================================================== --- linux.orig/drivers/md/dm-stripe.c +++ linux/drivers/md/dm-stripe.c @@ -311,8 +311,8 @@ static int stripe_map(struct dm_target * * */ -static int stripe_status(struct dm_target *ti, - status_type_t type, char *result, unsigned int maxlen) +static int stripe_status(struct dm_target *ti, status_type_t type, + unsigned status_flags, char *result, unsigned maxlen) { struct stripe_c *sc = (struct stripe_c *) ti->private; char buffer[sc->stripes + 1]; Index: linux/drivers/md/dm-thin.c =================================================================== --- linux.orig/drivers/md/dm-thin.c +++ linux/drivers/md/dm-thin.c @@ -5,6 +5,7 @@ */ #include "dm-thin-metadata.h" +#include "dm.h" #include #include @@ -2619,7 +2620,7 @@ static void emit_flags(struct pool_featu * / */ static int pool_status(struct dm_target *ti, status_type_t type, - char *result, unsigned maxlen) + unsigned status_flags, char *result, unsigned maxlen) { int r; unsigned sz = 0; @@ -2641,6 +2642,10 @@ static int pool_status(struct dm_target break; } + /* Commit to ensure statistics aren't out-of-date */ + if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) + (void) commit_or_fallback(pool); + r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id); if (r) @@ -2968,7 +2973,7 @@ static void thin_postsuspend(struct dm_t * */ static int thin_status(struct dm_target *ti, status_type_t type, - char *result, unsigned maxlen) + unsigned status_flags, char *result, unsigned maxlen) { int r; ssize_t sz = 0; Index: linux/drivers/md/dm-verity.c =================================================================== --- linux.orig/drivers/md/dm-verity.c +++ linux/drivers/md/dm-verity.c @@ -515,7 +515,7 @@ static int verity_map(struct dm_target * * Status: V (valid) or C (corruption found) */ static int verity_status(struct dm_target *ti, status_type_t type, - char *result, unsigned maxlen) + unsigned status_flags, char *result, unsigned maxlen) { struct dm_verity *v = ti->private; unsigned sz = 0; Index: linux/drivers/md/dm.h =================================================================== --- linux.orig/drivers/md/dm.h +++ linux/drivers/md/dm.h @@ -23,6 +23,11 @@ #define DM_SUSPEND_NOFLUSH_FLAG (1 << 1) /* + * Status feature flags + */ +#define DM_STATUS_NOFLUSH_FLAG (1 << 0) + +/* * Type of table and mapped_device's mempool */ #define DM_TYPE_NONE 0 Index: linux/include/linux/device-mapper.h =================================================================== --- linux.orig/include/linux/device-mapper.h +++ linux/include/linux/device-mapper.h @@ -72,7 +72,7 @@ typedef int (*dm_preresume_fn) (struct d typedef void (*dm_resume_fn) (struct dm_target *ti); typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, - char *result, unsigned int maxlen); + unsigned status_flags, char *result, unsigned maxlen); typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv); Index: linux/include/linux/dm-ioctl.h =================================================================== --- linux.orig/include/linux/dm-ioctl.h +++ linux/include/linux/dm-ioctl.h @@ -267,9 +267,9 @@ enum { #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 22 -#define DM_VERSION_PATCHLEVEL 1 -#define DM_VERSION_EXTRA "-ioctl (2012-06-01)" +#define DM_VERSION_MINOR 23 +#define DM_VERSION_PATCHLEVEL 0 +#define DM_VERSION_EXTRA "-ioctl (2012-07-25)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ @@ -307,6 +307,8 @@ enum { /* * Set this to suspend without flushing queued ios. + * Also disables flushing uncommitted changes in the thin target before + * generating statistics for DM_TABLE_STATUS and DM_DEV_WAIT. */ #define DM_NOFLUSH_FLAG (1 << 11) /* In */