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authorTrond Myklebust <Trond.Myklebust@netapp.com>2012-05-31 12:22:33 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-31 11:41:36 -0700
commit1d59d61f606547f0712aa6971f91f71154071c99 (patch)
treecb2fd4b9ce3e3ee9440d566d43ea350221edfc8e /fs/inode.c
parent2d117403b30cd7301af60d7d54b279a9f566d10d (diff)
downloadlinux-1d59d61f606547f0712aa6971f91f71154071c99.tar.gz
NFS: Ensure that setattr and getattr wait for O_DIRECT write completion
Use the same mechanism as the block devices are using, but move the helper functions from fs/direct-io.c into fs/inode.c to remove the dependency on CONFIG_BLOCK. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Fred Isaman <iisaman@netapp.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/inode.c')
-rw-r--r--fs/inode.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 6bc8761cc33..c474c1d7062 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1748,3 +1748,50 @@ bool inode_owner_or_capable(const struct inode *inode)
return false;
}
EXPORT_SYMBOL(inode_owner_or_capable);
+
+/*
+ * Direct i/o helper functions
+ */
+static void __inode_dio_wait(struct inode *inode)
+{
+ wait_queue_head_t *wq = bit_waitqueue(&inode->i_state, __I_DIO_WAKEUP);
+ DEFINE_WAIT_BIT(q, &inode->i_state, __I_DIO_WAKEUP);
+
+ do {
+ prepare_to_wait(wq, &q.wait, TASK_UNINTERRUPTIBLE);
+ if (atomic_read(&inode->i_dio_count))
+ schedule();
+ } while (atomic_read(&inode->i_dio_count));
+ finish_wait(wq, &q.wait);
+}
+
+/**
+ * inode_dio_wait - wait for outstanding DIO requests to finish
+ * @inode: inode to wait for
+ *
+ * Waits for all pending direct I/O requests to finish so that we can
+ * proceed with a truncate or equivalent operation.
+ *
+ * Must be called under a lock that serializes taking new references
+ * to i_dio_count, usually by inode->i_mutex.
+ */
+void inode_dio_wait(struct inode *inode)
+{
+ if (atomic_read(&inode->i_dio_count))
+ __inode_dio_wait(inode);
+}
+EXPORT_SYMBOL(inode_dio_wait);
+
+/*
+ * inode_dio_done - signal finish of a direct I/O requests
+ * @inode: inode the direct I/O happens on
+ *
+ * This is called once we've finished processing a direct I/O request,
+ * and is used to wake up callers waiting for direct I/O to be quiesced.
+ */
+void inode_dio_done(struct inode *inode)
+{
+ if (atomic_dec_and_test(&inode->i_dio_count))
+ wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
+}
+EXPORT_SYMBOL(inode_dio_done);