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Commit 97461518 authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Linus Torvalds
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[PATCH] convert ext3's truncate_sem to a mutex 



ext3's truncate_sem is always released in the same function it's taken
and it otherwise is a mutex as well..

Signed-off-by: default avatarArjan van de Ven <arjan@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7bf6d78d

fs/ext3/file.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -37,9 +37,9 @@ static int ext3_release_file (struct inode * inode, struct file * filp) 
	if ((filp->f_mode & FMODE_WRITE) &&

	if ((filp->f_mode & FMODE_WRITE) &&

			(atomic_read(&inode->i_writecount) == 1))

			(atomic_read(&inode->i_writecount) == 1))

	{

	{

		down(&EXT3_I(inode)->truncate_sem);

		mutex_lock(&EXT3_I(inode)->truncate_mutex);

		ext3_discard_reservation(inode);

		ext3_discard_reservation(inode);

		up(&EXT3_I(inode)->truncate_sem);

		mutex_unlock(&EXT3_I(inode)->truncate_mutex);

	}

	}

	if (is_dx(inode) && filp->private_data)

	if (is_dx(inode) && filp->private_data)

		ext3_htree_free_dir_info(filp->private_data);

		ext3_htree_free_dir_info(filp->private_data);

fs/ext3/inode.c

+7 −7
Original line number Original line Diff line number Diff line
@@ -702,7 +702,7 @@ ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock, 
	if (!create || err == -EIO)

	if (!create || err == -EIO)

		goto cleanup;

		goto cleanup;





	down(&ei->truncate_sem);

	mutex_lock(&ei->truncate_mutex);





	/*

	/*

	 * If the indirect block is missing while we are reading

	 * If the indirect block is missing while we are reading
@@ -723,7 +723,7 @@ ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock, 
		}

		}

		partial = ext3_get_branch(inode, depth, offsets, chain, &err);

		partial = ext3_get_branch(inode, depth, offsets, chain, &err);

		if (!partial) {

		if (!partial) {

			up(&ei->truncate_sem);

			mutex_unlock(&ei->truncate_mutex);

			if (err)

			if (err)

				goto cleanup;

				goto cleanup;

			clear_buffer_new(bh_result);

			clear_buffer_new(bh_result);
@@ -759,13 +759,13 @@ ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock, 
		err = ext3_splice_branch(handle, inode, iblock, chain,

		err = ext3_splice_branch(handle, inode, iblock, chain,

					 partial, left);

					 partial, left);

	/*

	/*

	 * i_disksize growing is protected by truncate_sem.  Don't forget to

	 * i_disksize growing is protected by truncate_mutex.  Don't forget to

	 * protect it if you're about to implement concurrent

	 * protect it if you're about to implement concurrent

	 * ext3_get_block() -bzzz

	 * ext3_get_block() -bzzz

	*/

	*/

	if (!err && extend_disksize && inode->i_size > ei->i_disksize)

	if (!err && extend_disksize && inode->i_size > ei->i_disksize)

		ei->i_disksize = inode->i_size;

		ei->i_disksize = inode->i_size;

	up(&ei->truncate_sem);

	mutex_unlock(&ei->truncate_mutex);

	if (err)

	if (err)

		goto cleanup;

		goto cleanup;
@@ -1227,7 +1227,7 @@ static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh) 
 *	ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...

 *	ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...

 *

 *

 * Same applies to ext3_get_block().  We will deadlock on various things like

 * Same applies to ext3_get_block().  We will deadlock on various things like

 * lock_journal and i_truncate_sem.

 * lock_journal and i_truncate_mutex.

 *

 *

 * Setting PF_MEMALLOC here doesn't work - too many internal memory

 * Setting PF_MEMALLOC here doesn't work - too many internal memory

 * allocations fail.

 * allocations fail.
@@ -2161,7 +2161,7 @@ void ext3_truncate(struct inode * inode) 
	 * From here we block out all ext3_get_block() callers who want to

	 * From here we block out all ext3_get_block() callers who want to

	 * modify the block allocation tree.

	 * modify the block allocation tree.

	 */

	 */

	down(&ei->truncate_sem);

	mutex_lock(&ei->truncate_mutex);





	if (n == 1) {		/* direct blocks */

	if (n == 1) {		/* direct blocks */

		ext3_free_data(handle, inode, NULL, i_data+offsets[0],

		ext3_free_data(handle, inode, NULL, i_data+offsets[0],
@@ -2228,7 +2228,7 @@ void ext3_truncate(struct inode * inode) 




	ext3_discard_reservation(inode);

	ext3_discard_reservation(inode);





	up(&ei->truncate_sem);

	mutex_unlock(&ei->truncate_mutex);

	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;

	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;

	ext3_mark_inode_dirty(handle, inode);

	ext3_mark_inode_dirty(handle, inode);

fs/ext3/ioctl.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -182,7 +182,7 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd, 
		 * need to allocate reservation structure for this inode

		 * need to allocate reservation structure for this inode

		 * before set the window size

		 * before set the window size

		 */

		 */

		down(&ei->truncate_sem);

		mutex_lock(&ei->truncate_mutex);

		if (!ei->i_block_alloc_info)

		if (!ei->i_block_alloc_info)

			ext3_init_block_alloc_info(inode);

			ext3_init_block_alloc_info(inode);
@@ -190,7 +190,7 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd, 
			struct ext3_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;

			struct ext3_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;

			rsv->rsv_goal_size = rsv_window_size;

			rsv->rsv_goal_size = rsv_window_size;

		}

		}

		up(&ei->truncate_sem);

		mutex_unlock(&ei->truncate_mutex);

		return 0;

		return 0;

	}

	}

	case EXT3_IOC_GROUP_EXTEND: {

	case EXT3_IOC_GROUP_EXTEND: {

fs/ext3/super.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -472,7 +472,7 @@ static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) 
#ifdef CONFIG_EXT3_FS_XATTR

#ifdef CONFIG_EXT3_FS_XATTR

		init_rwsem(&ei->xattr_sem);

		init_rwsem(&ei->xattr_sem);

#endif

#endif

		init_MUTEX(&ei->truncate_sem);

		mutex_init(&ei->truncate_mutex);

		inode_init_once(&ei->vfs_inode);

		inode_init_once(&ei->vfs_inode);

	}

	}

}

}

include/linux/ext3_fs_i.h

+4 −3
Original line number Original line Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/rwsem.h>

#include <linux/rwsem.h>

#include <linux/rbtree.h>

#include <linux/rbtree.h>

#include <linux/seqlock.h>

#include <linux/seqlock.h>

#include <linux/mutex.h>





struct ext3_reserve_window {

struct ext3_reserve_window {

	__u32			_rsv_start;	/* First byte reserved */

	__u32			_rsv_start;	/* First byte reserved */
@@ -122,16 +123,16 @@ struct ext3_inode_info { 
	__u16 i_extra_isize;

	__u16 i_extra_isize;





	/*

	/*

	 * truncate_sem is for serialising ext3_truncate() against

	 * truncate_mutex is for serialising ext3_truncate() against

	 * ext3_getblock().  In the 2.4 ext2 design, great chunks of inode's

	 * ext3_getblock().  In the 2.4 ext2 design, great chunks of inode's

	 * data tree are chopped off during truncate. We can't do that in

	 * data tree are chopped off during truncate. We can't do that in

	 * ext3 because whenever we perform intermediate commits during

	 * ext3 because whenever we perform intermediate commits during

	 * truncate, the inode and all the metadata blocks *must* be in a

	 * truncate, the inode and all the metadata blocks *must* be in a

	 * consistent state which allows truncation of the orphans to restart

	 * consistent state which allows truncation of the orphans to restart

	 * during recovery.  Hence we must fix the get_block-vs-truncate race

	 * during recovery.  Hence we must fix the get_block-vs-truncate race

	 * by other means, so we have truncate_sem.

	 * by other means, so we have truncate_mutex.

	 */

	 */

	struct semaphore truncate_sem;

	struct mutex truncate_mutex;

	struct inode vfs_inode;

	struct inode vfs_inode;

};

};