From 1f4e0ff07980820977f45d6a5dbc81d3bb9ce4d3 Mon Sep 17 00:00:00 2001 From: Alasdair G Kergon Date: Fri, 27 Jul 2012 15:08:16 +0100 Subject: dm thin: commit before gathering status 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-thin.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers/md/dm-thin.c') diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 087e9b34d290..af1fc3b2c2ad 100644 --- a/drivers/md/dm-thin.c +++ b/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_features *pf, char *result, * / */ 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@@ static int pool_status(struct dm_target *ti, status_type_t type, break; } + /* Commit to ensure statistics aren't out-of-date */ + if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti)) + (void) commit_or_fallback(pool); + r = dm_pool_get_metadata_transaction_id(pool-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_target *ti) * */ 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; -- cgit v1.2.3