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Commit 323ee8fc authored by Al Viro's avatar Al Viro
Browse files

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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 552a9d48

fs/hfsplus/catalog.c

+3 −0
Original line number Diff line number Diff line
@@ -374,12 +374,15 @@ int hfsplus_delete_cat(u32 cnid, struct inode *dir, struct qstr *str) 
		hfsplus_free_fork(sb, cnid, &fork, HFSPLUS_TYPE_RSRC);

	}



	/* we only need to take spinlock for exclusion with ->release() */

	spin_lock(&HFSPLUS_I(dir)->open_dir_lock);

	list_for_each(pos, &HFSPLUS_I(dir)->open_dir_list) {

		struct hfsplus_readdir_data *rd =

			list_entry(pos, struct hfsplus_readdir_data, list);

		if (fd.tree->keycmp(fd.search_key, (void *)&rd->key) < 0)

			rd->file->f_pos--;

	}

	spin_unlock(&HFSPLUS_I(dir)->open_dir_lock);



	err = hfs_brec_remove(&fd);

	if (err)

fs/hfsplus/dir.c

+9 −3
Original line number Diff line number Diff line
@@ -271,8 +271,14 @@ static int hfsplus_readdir(struct file *file, struct dir_context *ctx) 
		}

		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,

fs/hfsplus/hfsplus_fs.h

+1 −0
Original line number Diff line number Diff line
@@ -244,6 +244,7 @@ struct hfsplus_inode_info { 
	u8 userflags;		/* BSD user file flags */

	u32 subfolders;		/* Subfolder count (HFSX only) */

	struct list_head open_dir_list;

	spinlock_t open_dir_lock;

	loff_t phys_size;



	struct inode vfs_inode;

fs/hfsplus/inode.c

+1 −0
Original line number Diff line number Diff line
@@ -374,6 +374,7 @@ struct inode *hfsplus_new_inode(struct super_block *sb, umode_t mode) 


	hip = HFSPLUS_I(inode);

	INIT_LIST_HEAD(&hip->open_dir_list);

	spin_lock_init(&hip->open_dir_lock);

	mutex_init(&hip->extents_lock);

	atomic_set(&hip->opencnt, 0);

	hip->extent_state = 0;

fs/hfsplus/super.c

+1 −0
Original line number Diff line number Diff line
@@ -67,6 +67,7 @@ struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino) 
		return inode;



	INIT_LIST_HEAD(&HFSPLUS_I(inode)->open_dir_list);

	spin_lock_init(&HFSPLUS_I(inode)->open_dir_lock);

	mutex_init(&HFSPLUS_I(inode)->extents_lock);

	HFSPLUS_I(inode)->flags = 0;

	HFSPLUS_I(inode)->extent_state = 0;