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authorPaolo Bonzini <pbonzini@redhat.com>2022-09-23 10:06:08 -0400
committerPaolo Bonzini <pbonzini@redhat.com>2022-09-23 10:06:08 -0400
commit69604fe76e58c9d195e48b41d019b07fc27ce9d7 (patch)
treec9d1e7cfe406a8f168c3aceaf989eea0275d3045 /include/linux/buffer_head.h
parent50b2d49bafa16e6311ab2da82f5aafc5f9ada99b (diff)
parent189e7d876e48d7c791fe1c9c01516f70f5621a9f (diff)
Merge tag 'kvm-s390-master-6.0-2' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
More pci fixes Fix for a code analyser warning
Diffstat (limited to 'include/linux/buffer_head.h')
-rw-r--r--include/linux/buffer_head.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 089c9ade4325..df518c429667 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -138,6 +138,17 @@ BUFFER_FNS(Defer_Completion, defer_completion)
static __always_inline void set_buffer_uptodate(struct buffer_head *bh)
{
/*
+ * If somebody else already set this uptodate, they will
+ * have done the memory barrier, and a reader will thus
+ * see *some* valid buffer state.
+ *
+ * Any other serialization (with IO errors or whatever that
+ * might clear the bit) has to come from other state (eg BH_Lock).
+ */
+ if (test_bit(BH_Uptodate, &bh->b_state))
+ return;
+
+ /*
* make it consistent with folio_mark_uptodate
* pairs with smp_load_acquire in buffer_uptodate
*/