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authorBrian Foster <bfoster@redhat.com>2012-07-16 15:23:50 -0400
committerMiklos Szeredi <mszeredi@suse.cz>2012-07-18 16:09:40 +0200
commita8894274a3581125fb311eabfc97cd0123740c5e (patch)
tree5d229b3f11b1e9800b95f47bdd1570c2b40e7675
parenteed2179efe1aac145bf6d54b925b750976380fa6 (diff)
downloadop-kernel-dev-a8894274a3581125fb311eabfc97cd0123740c5e.zip
op-kernel-dev-a8894274a3581125fb311eabfc97cd0123740c5e.tar.gz
fuse: update attributes on aio_read
A fuse-based network filesystem might allow for the inode and/or file data to change unexpectedly. A local client that opens and repeatedly reads a file might never pick up on such changes and indefinitely return stale data. Always invoke fuse_update_attributes() in the read path to cause an attr revalidation when the attributes expire. This leads to a page cache invalidation if necessary and ensures fuse issues new read requests to the fuse client. The original logic (reval only on reads beyond EOF) is preserved unless the client specifies FUSE_AUTO_INVAL_DATA on init. Signed-off-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
-rw-r--r--fs/fuse/file.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index b321a68..5800101 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -703,13 +703,16 @@ static ssize_t fuse_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
struct inode *inode = iocb->ki_filp->f_mapping->host;
+ struct fuse_conn *fc = get_fuse_conn(inode);
- if (pos + iov_length(iov, nr_segs) > i_size_read(inode)) {
+ /*
+ * In auto invalidate mode, always update attributes on read.
+ * Otherwise, only update if we attempt to read past EOF (to ensure
+ * i_size is up to date).
+ */
+ if (fc->auto_inval_data ||
+ (pos + iov_length(iov, nr_segs) > i_size_read(inode))) {
int err;
- /*
- * If trying to read past EOF, make sure the i_size
- * attribute is up-to-date.
- */
err = fuse_update_attributes(inode, NULL, iocb->ki_filp, NULL);
if (err)
return err;
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