[PATCH 2/2] mm: swap: print starting physical block offset in swapon

[Sukrit Bhatnagar]

When a swapfile is created for hibernation purposes, we always need
the starting physical block offset, which is usually determined using
userspace commands such as filefrag.

It would be good to have that value printed when we do swapon and get
that value directly from dmesg.

Signed-off-by: Sukrit Bhatnagar <Sukrit.Bhatnagar@xxxxxxxx>
---
 mm/swapfile.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/swapfile.c b/mm/swapfile.c
index f6ca215fb92f..53c9187d5fbe 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3264,8 +3264,9 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 		  (swap_flags & SWAP_FLAG_PRIO_MASK) >> SWAP_FLAG_PRIO_SHIFT;
 	enable_swap_info(p, prio, swap_map, cluster_info);
 
-	pr_info("Adding %uk swap on %s.  Priority:%d extents:%d across:%lluk %s%s%s%s\n",
+	pr_info("Adding %uk swap on %s. Priority:%d extents:%d start:%llu across:%lluk %s%s%s%s\n",
 		K(p->pages), name->name, p->prio, nr_extents,
+		(unsigned long long)first_se(p)->start_block,
 		K((unsigned long long)span),
 		(p->flags & SWP_SOLIDSTATE) ? "SS" : "",
 		(p->flags & SWP_DISCARDABLE) ? "D" : "",
-- 
2.34.1