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authorPavel Emelyanov <xemul@openvz.org>2013-10-10 17:10:46 +0400
committerMiklos Szeredi <mszeredi@suse.cz>2014-04-02 17:38:48 +0400
commit8373200b124d03de7fa2e99be56de8642e604e9e (patch)
tree853b6590ced17b0449883093350bf681e5e9cbd7 /fs/fuse/inode.c
parentd5cd66c58edf10a7ee786659994595fd43995aab (diff)
downloadlinux-8373200b124d03de7fa2e99be56de8642e604e9e.tar.xz
fuse: Trust kernel i_size only
Make fuse think that when writeback is on the inode's i_size is always up-to-date and not update it with the value received from the userspace. This is done because the page cache code may update i_size without letting the FS know. This assumption implies fixing the previously introduced short-read helper -- when a short read occurs the 'hole' is filled with zeroes. fuse_file_fallocate() is also fixed because now we should keep i_size up to date, so it must be updated if FUSE_FALLOCATE request succeeded. Signed-off-by: Maxim V. Patlasov <MPatlasov@parallels.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Diffstat (limited to 'fs/fuse/inode.c')
-rw-r--r--fs/fuse/inode.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index d468643a68b2..c668c8436894 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);
+ bool is_wb = fc->writeback_cache;
loff_t oldsize;
struct timespec old_mtime;
@@ -211,10 +212,16 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
fuse_change_attributes_common(inode, attr, attr_valid);
oldsize = inode->i_size;
- i_size_write(inode, attr->size);
+ /*
+ * In case of writeback_cache enabled, the cached writes beyond EOF
+ * extend local i_size without keeping userspace server in sync. So,
+ * attr->size coming from server can be stale. We cannot trust it.
+ */
+ if (!is_wb || !S_ISREG(inode->i_mode))
+ i_size_write(inode, attr->size);
spin_unlock(&fc->lock);
- if (S_ISREG(inode->i_mode)) {
+ if (!is_wb && S_ISREG(inode->i_mode)) {
bool inval = false;
if (oldsize != attr->size) {