fuse: decrement nlink on overwriting rename

Rename didn't decrement/clear nlink on overwritten target inode.

Create a common helper fuse_entry_unlinked() that handles this for unlink,
rmdir and rename.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Miklos Szeredi 2021-10-22 17:03:02 +02:00
parent 84840efc3c
commit cefd1b8327

View file

@ -755,6 +755,29 @@ void fuse_update_ctime(struct inode *inode)
}
}
static void fuse_entry_unlinked(struct dentry *entry)
{
struct inode *inode = d_inode(entry);
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
spin_lock(&fi->lock);
fi->attr_version = atomic64_inc_return(&fc->attr_version);
/*
* If i_nlink == 0 then unlink doesn't make sense, yet this can
* happen if userspace filesystem is careless. It would be
* difficult to enforce correct nlink usage so just ignore this
* condition here
*/
if (S_ISDIR(inode->i_mode))
clear_nlink(inode);
else if (inode->i_nlink > 0)
drop_nlink(inode);
spin_unlock(&fi->lock);
fuse_invalidate_entry_cache(entry);
fuse_update_ctime(inode);
}
static int fuse_unlink(struct inode *dir, struct dentry *entry)
{
int err;
@ -771,23 +794,8 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry)
args.in_args[0].value = entry->d_name.name;
err = fuse_simple_request(fm, &args);
if (!err) {
struct inode *inode = d_inode(entry);
struct fuse_inode *fi = get_fuse_inode(inode);
spin_lock(&fi->lock);
fi->attr_version = atomic64_inc_return(&fm->fc->attr_version);
/*
* If i_nlink == 0 then unlink doesn't make sense, yet this can
* happen if userspace filesystem is careless. It would be
* difficult to enforce correct nlink usage so just ignore this
* condition here
*/
if (inode->i_nlink > 0)
drop_nlink(inode);
spin_unlock(&fi->lock);
fuse_dir_changed(dir);
fuse_invalidate_entry_cache(entry);
fuse_update_ctime(inode);
fuse_entry_unlinked(entry);
} else if (err == -EINTR)
fuse_invalidate_entry(entry);
return err;
@ -809,9 +817,8 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry)
args.in_args[0].value = entry->d_name.name;
err = fuse_simple_request(fm, &args);
if (!err) {
clear_nlink(d_inode(entry));
fuse_dir_changed(dir);
fuse_invalidate_entry_cache(entry);
fuse_entry_unlinked(entry);
} else if (err == -EINTR)
fuse_invalidate_entry(entry);
return err;
@ -851,10 +858,8 @@ static int fuse_rename_common(struct inode *olddir, struct dentry *oldent,
fuse_dir_changed(newdir);
/* newent will end up negative */
if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent)) {
fuse_invalidate_entry_cache(newent);
fuse_update_ctime(d_inode(newent));
}
if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent))
fuse_entry_unlinked(newent);
} else if (err == -EINTR) {
/* If request was interrupted, DEITY only knows if the
rename actually took place. If the invalidation