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Commit 7fcc99f4 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Christoph Hellwig
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hfsplus: add missing extent locking in hfsplus_write_inode 



Most of the extent handling code already does proper SMP locking, but
hfsplus_write_inode was calling into hfsplus_ext_write_extent without
taking the extents_lock.  Fix this by splitting hfsplus_ext_write_extent
into an internal helper that expects the lock, and a public interface
that first acquires it.

Also add a few locking asserts and document the locking rules in
hfsplus_fs.h.

Signed-off-by: default avatarChristoph Hellwig <hch@tuxera.com>
parent 89755dca

fs/hfsplus/extents.c

+13 −2
Original line number Diff line number Diff line
@@ -88,6 +88,8 @@ static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data 
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);

	int res;



	WARN_ON(!mutex_is_locked(&hip->extents_lock));



	hfsplus_ext_build_key(fd->search_key, inode->i_ino, hip->cached_start,

			      HFSPLUS_IS_RSRC(inode) ?

				HFSPLUS_TYPE_RSRC : HFSPLUS_TYPE_DATA);
@@ -108,7 +110,7 @@ static void __hfsplus_ext_write_extent(struct inode *inode, struct hfs_find_data 
	}

}



void hfsplus_ext_write_extent(struct inode *inode)

static void hfsplus_ext_write_extent_locked(struct inode *inode)

{

	if (HFSPLUS_I(inode)->flags & HFSPLUS_FLG_EXT_DIRTY) {

		struct hfs_find_data fd;
@@ -119,6 +121,13 @@ void hfsplus_ext_write_extent(struct inode *inode) 
	}

}



void hfsplus_ext_write_extent(struct inode *inode)

{

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

	hfsplus_ext_write_extent_locked(inode);

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

}



static inline int __hfsplus_ext_read_extent(struct hfs_find_data *fd,

					    struct hfsplus_extent *extent,

					    u32 cnid, u32 block, u8 type)
@@ -144,6 +153,8 @@ static inline int __hfsplus_ext_cache_extent(struct hfs_find_data *fd, struct in 
	struct hfsplus_inode_info *hip = HFSPLUS_I(inode);

	int res;



	WARN_ON(!mutex_is_locked(&hip->extents_lock));



	if (hip->flags & HFSPLUS_FLG_EXT_DIRTY)

		__hfsplus_ext_write_extent(inode, fd);
@@ -433,7 +444,7 @@ out: 


insert_extent:

	dprint(DBG_EXTENT, "insert new extent\n");

	hfsplus_ext_write_extent(inode);

	hfsplus_ext_write_extent_locked(inode);



	memset(hip->cached_extents, 0, sizeof(hfsplus_extent_rec));

	hip->cached_extents[0].start_block = cpu_to_be32(start);

fs/hfsplus/hfsplus_fs.h

+21 −13
Original line number Diff line number Diff line
@@ -158,28 +158,36 @@ struct hfsplus_sb_info { 




struct hfsplus_inode_info {

	struct mutex extents_lock;

	u32 clump_blocks, alloc_blocks;

	sector_t fs_blocks;

	/* Allocation extents from catalog record or volume header */

	hfsplus_extent_rec first_extents;

	u32 first_blocks;

	hfsplus_extent_rec cached_extents;

	u32 cached_start, cached_blocks;

	atomic_t opencnt;



	struct inode *rsrc_inode;

	/*

	 * Extent allocation information, protected by extents_lock.

	 */

	u32 first_blocks;

	u32 clump_blocks;

	u32 alloc_blocks;

	u32 cached_start;

	u32 cached_blocks;

	hfsplus_extent_rec first_extents;

	hfsplus_extent_rec cached_extents;

	unsigned long flags;

	struct mutex extents_lock;



	/*

	 * Immutable data.

	 */

	struct inode *rsrc_inode;

	__be32 create_date;

	/* Device number in hfsplus_permissions in catalog */

	u32 dev;

	/* BSD system and user file flags */

	u8 rootflags;

	u8 userflags;



	/*

	 * Protected by i_mutex.

	 */

	sector_t fs_blocks;

	u8 rootflags, userflags;	/* BSD system and user file flags */

	struct list_head open_dir_list;

	loff_t phys_size;



	struct inode vfs_inode;

};