From 323ee8fc544d407eb053471b9607f95f987f5f12 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 12 May 2016 20:02:09 -0400 Subject: hfsplus: switch to ->iterate_shared() We need to protect the list of hfsplus_readdir_data against parallel insertions (in readdir) and removals (in release). Add a spinlock for that. Note that it has nothing to do with protection of hfsplus_readdir_data->key - we have an exclusion between hfsplus_readdir() and hfsplus_delete_cat() on directory lock and between several hfsplus_readdir() for the same struct file on ->f_pos_lock. The spinlock is strictly for list changes. Signed-off-by: Al Viro --- fs/hfsplus/dir.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'fs/hfsplus/dir.c') diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c index a4e867e..42e1286 100644 --- a/fs/hfsplus/dir.c +++ b/fs/hfsplus/dir.c @@ -271,8 +271,14 @@ next: } file->private_data = rd; rd->file = file; + spin_lock(&HFSPLUS_I(inode)->open_dir_lock); list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list); + spin_unlock(&HFSPLUS_I(inode)->open_dir_lock); } + /* + * Can be done after the list insertion; exclusion with + * hfsplus_delete_cat() is provided by directory lock. + */ memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key)); out: kfree(strbuf); @@ -284,9 +290,9 @@ static int hfsplus_dir_release(struct inode *inode, struct file *file) { struct hfsplus_readdir_data *rd = file->private_data; if (rd) { - inode_lock(inode); + spin_lock(&HFSPLUS_I(inode)->open_dir_lock); list_del(&rd->list); - inode_unlock(inode); + spin_unlock(&HFSPLUS_I(inode)->open_dir_lock); kfree(rd); } return 0; @@ -569,7 +575,7 @@ const struct inode_operations hfsplus_dir_inode_operations = { const struct file_operations hfsplus_dir_operations = { .fsync = hfsplus_file_fsync, .read = generic_read_dir, - .iterate = hfsplus_readdir, + .iterate_shared = hfsplus_readdir, .unlocked_ioctl = hfsplus_ioctl, .llseek = generic_file_llseek, .release = hfsplus_dir_release, -- cgit v1.1