Commit 9df93939 authored by Jan Kara's avatar Jan Kara
Browse files

ext3: Use bitops to read/modify EXT3_I(inode)->i_state 



At several places we modify EXT3_I(inode)->i_state without holding i_mutex
(ext3_release_file, ext3_bmap, ext3_journalled_writepage, ext3_do_update_inode,
...). These modifications are racy and we can lose updates to i_state. So
convert handling of i_state to use bitops which are atomic.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 26245c94

fs/ext3/file.c

+2 −2
Original line number Diff line number Diff line
@@ -33,9 +33,9 @@ 
 */

static int ext3_release_file (struct inode * inode, struct file * filp)

{

	if (EXT3_I(inode)->i_state & EXT3_STATE_FLUSH_ON_CLOSE) {

	if (ext3_test_inode_state(inode, EXT3_STATE_FLUSH_ON_CLOSE)) {

		filemap_flush(inode->i_mapping);

		EXT3_I(inode)->i_state &= ~EXT3_STATE_FLUSH_ON_CLOSE;

		ext3_clear_inode_state(inode, EXT3_STATE_FLUSH_ON_CLOSE);

	}

	/* if we are the last writer on the inode, drop the block reservation */

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

fs/ext3/inode.c

+9 −9
Original line number Diff line number Diff line
@@ -1378,7 +1378,7 @@ static int ext3_journalled_write_end(struct file *file, 
	 */

	if (pos + len > inode->i_size && ext3_can_truncate(inode))

		ext3_orphan_add(handle, inode);

	EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;

	ext3_set_inode_state(inode, EXT3_STATE_JDATA);

	if (inode->i_size > EXT3_I(inode)->i_disksize) {

		EXT3_I(inode)->i_disksize = inode->i_size;

		ret2 = ext3_mark_inode_dirty(handle, inode);
@@ -1417,7 +1417,7 @@ static sector_t ext3_bmap(struct address_space *mapping, sector_t block) 
	journal_t *journal;

	int err;



	if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {

	if (ext3_test_inode_state(inode, EXT3_STATE_JDATA)) {

		/*

		 * This is a REALLY heavyweight approach, but the use of

		 * bmap on dirty files is expected to be extremely rare:
@@ -1436,7 +1436,7 @@ static sector_t ext3_bmap(struct address_space *mapping, sector_t block) 
		 * everything they get.

		 */



		EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;

		ext3_clear_inode_state(inode, EXT3_STATE_JDATA);

		journal = EXT3_JOURNAL(inode);

		journal_lock_updates(journal);

		err = journal_flush(journal);
@@ -1670,7 +1670,7 @@ static int ext3_journalled_writepage(struct page *page, 
				PAGE_CACHE_SIZE, NULL, write_end_fn);

		if (ret == 0)

			ret = err;

		EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;

		ext3_set_inode_state(inode, EXT3_STATE_JDATA);

		unlock_page(page);

	} else {

		/*
@@ -2402,7 +2402,7 @@ void ext3_truncate(struct inode *inode) 
		goto out_notrans;



	if (inode->i_size == 0 && ext3_should_writeback_data(inode))

		ei->i_state |= EXT3_STATE_FLUSH_ON_CLOSE;

		ext3_set_inode_state(inode, EXT3_STATE_FLUSH_ON_CLOSE);



	/*

	 * We have to lock the EOF page here, because lock_page() nests
@@ -2721,7 +2721,7 @@ int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc) 
{

	/* We have all inode data except xattrs in memory here. */

	return __ext3_get_inode_loc(inode, iloc,

		!(EXT3_I(inode)->i_state & EXT3_STATE_XATTR));

		!ext3_test_inode_state(inode, EXT3_STATE_XATTR));

}



void ext3_set_inode_flags(struct inode *inode)
@@ -2893,7 +2893,7 @@ struct inode *ext3_iget(struct super_block *sb, unsigned long ino) 
					EXT3_GOOD_OLD_INODE_SIZE +

					ei->i_extra_isize;

			if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))

				 ei->i_state |= EXT3_STATE_XATTR;

				 ext3_set_inode_state(inode, EXT3_STATE_XATTR);

		}

	} else

		ei->i_extra_isize = 0;
@@ -2955,7 +2955,7 @@ again: 


	/* For fields not not tracking in the in-memory inode,

	 * initialise them to zero for new inodes. */

	if (ei->i_state & EXT3_STATE_NEW)

	if (ext3_test_inode_state(inode, EXT3_STATE_NEW))

		memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);



	ext3_get_inode_flags(ei);
@@ -3052,7 +3052,7 @@ again: 
	rc = ext3_journal_dirty_metadata(handle, bh);

	if (!err)

		err = rc;

	ei->i_state &= ~EXT3_STATE_NEW;

	ext3_clear_inode_state(inode, EXT3_STATE_NEW);



	atomic_set(&ei->i_sync_tid, handle->h_transaction->t_tid);

out_brelse:

fs/ext3/xattr.c

+7 −7
Original line number Diff line number Diff line
@@ -274,7 +274,7 @@ ext3_xattr_ibody_get(struct inode *inode, int name_index, const char *name, 
	void *end;

	int error;



	if (!(EXT3_I(inode)->i_state & EXT3_STATE_XATTR))

	if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))

		return -ENODATA;

	error = ext3_get_inode_loc(inode, &iloc);

	if (error)
@@ -403,7 +403,7 @@ ext3_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) 
	void *end;

	int error;



	if (!(EXT3_I(inode)->i_state & EXT3_STATE_XATTR))

	if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))

		return 0;

	error = ext3_get_inode_loc(inode, &iloc);

	if (error)
@@ -882,7 +882,7 @@ ext3_xattr_ibody_find(struct inode *inode, struct ext3_xattr_info *i, 
	is->s.base = is->s.first = IFIRST(header);

	is->s.here = is->s.first;

	is->s.end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;

	if (EXT3_I(inode)->i_state & EXT3_STATE_XATTR) {

	if (ext3_test_inode_state(inode, EXT3_STATE_XATTR)) {

		error = ext3_xattr_check_names(IFIRST(header), is->s.end);

		if (error)

			return error;
@@ -914,10 +914,10 @@ ext3_xattr_ibody_set(handle_t *handle, struct inode *inode, 
	header = IHDR(inode, ext3_raw_inode(&is->iloc));

	if (!IS_LAST_ENTRY(s->first)) {

		header->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);

		EXT3_I(inode)->i_state |= EXT3_STATE_XATTR;

		ext3_set_inode_state(inode, EXT3_STATE_XATTR);

	} else {

		header->h_magic = cpu_to_le32(0);

		EXT3_I(inode)->i_state &= ~EXT3_STATE_XATTR;

		ext3_clear_inode_state(inode, EXT3_STATE_XATTR);

	}

	return 0;

}
@@ -967,10 +967,10 @@ ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, 
	if (error)

		goto cleanup;



	if (EXT3_I(inode)->i_state & EXT3_STATE_NEW) {

	if (ext3_test_inode_state(inode, EXT3_STATE_NEW)) {

		struct ext3_inode *raw_inode = ext3_raw_inode(&is.iloc);

		memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);

		EXT3_I(inode)->i_state &= ~EXT3_STATE_NEW;

		ext3_clear_inode_state(inode, EXT3_STATE_NEW);

	}



	error = ext3_xattr_ibody_find(inode, &i, &is);

include/linux/ext3_fs.h

+25 −8
Original line number Diff line number Diff line
@@ -202,14 +202,6 @@ static inline __u32 ext3_mask_flags(umode_t mode, __u32 flags) 
		return flags & EXT3_OTHER_FLMASK;

}



/*

 * Inode dynamic state flags

 */

#define EXT3_STATE_JDATA		0x00000001 /* journaled data exists */

#define EXT3_STATE_NEW			0x00000002 /* inode is newly created */

#define EXT3_STATE_XATTR		0x00000004 /* has in-inode xattrs */

#define EXT3_STATE_FLUSH_ON_CLOSE	0x00000008



/* Used to pass group descriptor data when online resize is done */

struct ext3_new_group_input {

	__u32 group;            /* Group number for this data */
@@ -560,6 +552,31 @@ static inline int ext3_valid_inum(struct super_block *sb, unsigned long ino) 
		(ino >= EXT3_FIRST_INO(sb) &&

		 ino <= le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count));

}



/*

 * Inode dynamic state flags

 */

enum {

	EXT3_STATE_JDATA,		/* journaled data exists */

	EXT3_STATE_NEW,			/* inode is newly created */

	EXT3_STATE_XATTR,		/* has in-inode xattrs */

	EXT3_STATE_FLUSH_ON_CLOSE,	/* flush dirty pages on close */

};



static inline int ext3_test_inode_state(struct inode *inode, int bit)

{

	return test_bit(bit, &EXT3_I(inode)->i_state);

}



static inline void ext3_set_inode_state(struct inode *inode, int bit)

{

	set_bit(bit, &EXT3_I(inode)->i_state);

}



static inline void ext3_clear_inode_state(struct inode *inode, int bit)

{

	clear_bit(bit, &EXT3_I(inode)->i_state);

}

#else

/* Assume that user mode programs are passing in an ext3fs superblock, not

 * a kernel struct super_block.  This will allow us to call the feature-test

include/linux/ext3_fs_i.h

+1 −1
Original line number Diff line number Diff line
@@ -87,7 +87,7 @@ struct ext3_inode_info { 
	 * near to their parent directory's inode.

	 */

	__u32	i_block_group;

	__u32	i_state;		/* Dynamic state flags for ext3 */

	unsigned long	i_state;	/* Dynamic state flags for ext3 */



	/* block reservation info */

	struct ext3_block_alloc_info *i_block_alloc_info;

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