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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-09-25 10:22:13 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-09-25 10:22:13 +0300
commita12c689209185c1ad872723a644d0cd27e52d49c (patch)
tree11c01d147a9241561eb7a3ad5a999e234be2750c /include/linux/buffer_head.h
parent4c8928850c9dc5c849ee37d89a79d44a283bdd87 (diff)
parent7e2cd21e02b35483ce8ea88da5732d4d3ec3a6c9 (diff)
downloadlinux-a12c689209185c1ad872723a644d0cd27e52d49c.tar.xz
Merge 7e2cd21e02b3 ("Merge tag 'tty-6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty") into tty-next
We need the tty fixes and api additions in this branch. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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
*/