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Diffstat (limited to 'fs/fuse/dir.c')
-rw-r--r--fs/fuse/dir.c84
1 files changed, 81 insertions, 3 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index c4807b3fc8a3..48b9971ecd97 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1107,6 +1107,50 @@ static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg)
}
/*
+ * Prevent concurrent writepages on inode
+ *
+ * This is done by adding a negative bias to the inode write counter
+ * and waiting for all pending writes to finish.
+ */
+void fuse_set_nowrite(struct inode *inode)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ BUG_ON(!mutex_is_locked(&inode->i_mutex));
+
+ spin_lock(&fc->lock);
+ BUG_ON(fi->writectr < 0);
+ fi->writectr += FUSE_NOWRITE;
+ spin_unlock(&fc->lock);
+ wait_event(fi->page_waitq, fi->writectr == FUSE_NOWRITE);
+}
+
+/*
+ * Allow writepages on inode
+ *
+ * Remove the bias from the writecounter and send any queued
+ * writepages.
+ */
+static void __fuse_release_nowrite(struct inode *inode)
+{
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ BUG_ON(fi->writectr != FUSE_NOWRITE);
+ fi->writectr = 0;
+ fuse_flush_writepages(inode);
+}
+
+void fuse_release_nowrite(struct inode *inode)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+
+ spin_lock(&fc->lock);
+ __fuse_release_nowrite(inode);
+ spin_unlock(&fc->lock);
+}
+
+/*
* Set attributes, and at the same time refresh them.
*
* Truncation is slightly complicated, because the 'truncate' request
@@ -1122,6 +1166,8 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
struct fuse_req *req;
struct fuse_setattr_in inarg;
struct fuse_attr_out outarg;
+ bool is_truncate = false;
+ loff_t oldsize;
int err;
if (!fuse_allow_task(fc, current))
@@ -1145,12 +1191,16 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
send_sig(SIGXFSZ, current, 0);
return -EFBIG;
}
+ is_truncate = true;
}
req = fuse_get_req(fc);
if (IS_ERR(req))
return PTR_ERR(req);
+ if (is_truncate)
+ fuse_set_nowrite(inode);
+
memset(&inarg, 0, sizeof(inarg));
memset(&outarg, 0, sizeof(outarg));
iattr_to_fattr(attr, &inarg);
@@ -1181,16 +1231,44 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr,
if (err) {
if (err == -EINTR)
fuse_invalidate_attr(inode);
- return err;
+ goto error;
}
if ((inode->i_mode ^ outarg.attr.mode) & S_IFMT) {
make_bad_inode(inode);
- return -EIO;
+ err = -EIO;
+ goto error;
+ }
+
+ spin_lock(&fc->lock);
+ fuse_change_attributes_common(inode, &outarg.attr,
+ attr_timeout(&outarg));
+ oldsize = inode->i_size;
+ i_size_write(inode, outarg.attr.size);
+
+ if (is_truncate) {
+ /* NOTE: this may release/reacquire fc->lock */
+ __fuse_release_nowrite(inode);
+ }
+ spin_unlock(&fc->lock);
+
+ /*
+ * Only call invalidate_inode_pages2() after removing
+ * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock.
+ */
+ if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
+ if (outarg.attr.size < oldsize)
+ fuse_truncate(inode->i_mapping, outarg.attr.size);
+ invalidate_inode_pages2(inode->i_mapping);
}
- fuse_change_attributes(inode, &outarg.attr, attr_timeout(&outarg), 0);
return 0;
+
+error:
+ if (is_truncate)
+ fuse_release_nowrite(inode);
+
+ return err;
}
static int fuse_setattr(struct dentry *entry, struct iattr *attr)