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authorBrian Foster <bfoster@redhat.com>2012-07-16 15:23:49 -0400
committerMiklos Szeredi <mszeredi@suse.cz>2012-07-18 16:09:40 +0200
commiteed2179efe1aac145bf6d54b925b750976380fa6 (patch)
treeb266220b26632c699a858b66c3d7b9ebc5853289
parent72d0d248ca8232dbd30d35b42d0d86e39b3e322b (diff)
downloadop-kernel-dev-eed2179efe1aac145bf6d54b925b750976380fa6.zip
op-kernel-dev-eed2179efe1aac145bf6d54b925b750976380fa6.tar.gz
fuse: invalidate inode mapping if mtime changes
We currently invalidate the inode address space mapping if the file size changes unexpectedly. In the case of a fuse network filesystem, a portion of a file could be overwritten remotely without changing the file size. Compare the old mtime as well to detect this condition and invalidate the mapping if the file has been updated. The original logic (to ignore changes in mtime) 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/inode.c27
1 files changed, 24 insertions, 3 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index dd37ee2..dd44016 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -197,6 +197,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
loff_t oldsize;
+ struct timespec old_mtime;
spin_lock(&fc->lock);
if (attr_version != 0 && fi->attr_version > attr_version) {
@@ -204,15 +205,35 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
return;
}
+ old_mtime = inode->i_mtime;
fuse_change_attributes_common(inode, attr, attr_valid);
oldsize = inode->i_size;
i_size_write(inode, attr->size);
spin_unlock(&fc->lock);
- if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
- truncate_pagecache(inode, oldsize, attr->size);
- invalidate_inode_pages2(inode->i_mapping);
+ if (S_ISREG(inode->i_mode)) {
+ bool inval = false;
+
+ if (oldsize != attr->size) {
+ truncate_pagecache(inode, oldsize, attr->size);
+ inval = true;
+ } else if (fc->auto_inval_data) {
+ struct timespec new_mtime = {
+ .tv_sec = attr->mtime,
+ .tv_nsec = attr->mtimensec,
+ };
+
+ /*
+ * Auto inval mode also checks and invalidates if mtime
+ * has changed.
+ */
+ if (!timespec_equal(&old_mtime, &new_mtime))
+ inval = true;
+ }
+
+ if (inval)
+ invalidate_inode_pages2(inode->i_mapping);
}
}
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