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Commit 19f5fb7a authored by Theodore Ts'o's avatar Theodore Ts'o
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ext4: Use bitops to read/modify EXT4_I(inode)->i_state 



At several places we modify EXT4_I(inode)->i_state without holding
i_mutex (ext4_release_file, ext4_bmap, ext4_journalled_writepage,
ext4_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.

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent d2eecb03

fs/ext4/ext4.h

+29 −12
Original line number Diff line number Diff line
@@ -313,17 +313,6 @@ static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags) 
		return flags & EXT4_OTHER_FLMASK;

}



/*

 * Inode dynamic state flags

 */

#define EXT4_STATE_JDATA		0x00000001 /* journaled data exists */

#define EXT4_STATE_NEW			0x00000002 /* inode is newly created */

#define EXT4_STATE_XATTR		0x00000004 /* has in-inode xattrs */

#define EXT4_STATE_NO_EXPAND		0x00000008 /* No space for expansion */

#define EXT4_STATE_DA_ALLOC_CLOSE	0x00000010 /* Alloc DA blks on close */

#define EXT4_STATE_EXT_MIGRATE		0x00000020 /* Inode is migrating */

#define EXT4_STATE_DIO_UNWRITTEN	0x00000040 /* need convert on dio done*/



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

struct ext4_new_group_input {

	__u32 group;		/* Group number for this data */
@@ -631,7 +620,7 @@ struct ext4_inode_info { 
	 * near to their parent directory's inode.

	 */

	ext4_group_t	i_block_group;

	__u32	i_state;		/* Dynamic state flags for ext4 */

	unsigned long	i_state_flags;		/* Dynamic state flags */



	ext4_lblk_t		i_dir_start_lookup;

#ifdef CONFIG_EXT4_FS_XATTR
@@ -1051,6 +1040,34 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino) 
		(ino >= EXT4_FIRST_INO(sb) &&

		 ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));

}



/*

 * Inode dynamic state flags

 */

enum {

	EXT4_STATE_JDATA,		/* journaled data exists */

	EXT4_STATE_NEW,			/* inode is newly created */

	EXT4_STATE_XATTR,		/* has in-inode xattrs */

	EXT4_STATE_NO_EXPAND,		/* No space for expansion */

	EXT4_STATE_DA_ALLOC_CLOSE,	/* Alloc DA blks on close */

	EXT4_STATE_EXT_MIGRATE,		/* Inode is migrating */

	EXT4_STATE_DIO_UNWRITTEN,	/* need convert on dio done*/

};



static inline int ext4_test_inode_state(struct inode *inode, int bit)

{

	return test_bit(bit, &EXT4_I(inode)->i_state_flags);

}



static inline void ext4_set_inode_state(struct inode *inode, int bit)

{

	set_bit(bit, &EXT4_I(inode)->i_state_flags);

}



static inline void ext4_clear_inode_state(struct inode *inode, int bit)

{

	clear_bit(bit, &EXT4_I(inode)->i_state_flags);

}

#else

/* Assume that user mode programs are passing in an ext4fs superblock, not

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

fs/ext4/extents.c

+4 −4
Original line number Diff line number Diff line
@@ -3076,7 +3076,7 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode, 
		if (io)

			io->flag = DIO_AIO_UNWRITTEN;

		else

			EXT4_I(inode)->i_state |= EXT4_STATE_DIO_UNWRITTEN;

			ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);

		goto out;

	}

	/* async DIO end_io complete, convert the filled extent to written */
@@ -3362,8 +3362,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, 
			if (io)

				io->flag = DIO_AIO_UNWRITTEN;

			else

				EXT4_I(inode)->i_state |=

					EXT4_STATE_DIO_UNWRITTEN;;

				ext4_set_inode_state(inode,

						     EXT4_STATE_DIO_UNWRITTEN);

		}

	}

	err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
@@ -3739,7 +3739,7 @@ static int ext4_xattr_fiemap(struct inode *inode, 
	int error = 0;



	/* in-inode? */

	if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {

	if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {

		struct ext4_iloc iloc;

		int offset;	/* offset of xattr in inode */

fs/ext4/file.c

+2 −2
Original line number Diff line number Diff line
@@ -35,9 +35,9 @@ 
 */

static int ext4_release_file(struct inode *inode, struct file *filp)

{

	if (EXT4_I(inode)->i_state & EXT4_STATE_DA_ALLOC_CLOSE) {

	if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {

		ext4_alloc_da_blocks(inode);

		EXT4_I(inode)->i_state &= ~EXT4_STATE_DA_ALLOC_CLOSE;

		ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);

	}

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

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

fs/ext4/ialloc.c

+2 −1
Original line number Diff line number Diff line
@@ -1029,7 +1029,8 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode, 
	inode->i_generation = sbi->s_next_generation++;

	spin_unlock(&sbi->s_next_gen_lock);



	ei->i_state = EXT4_STATE_NEW;

	ei->i_state_flags = 0;

	ext4_set_inode_state(inode, EXT4_STATE_NEW);



	ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize;

fs/ext4/inode.c

+20 −18
Original line number Diff line number Diff line
@@ -1307,7 +1307,7 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block, 
			 * i_data's format changing.  Force the migrate

			 * to fail by clearing migrate flags

			 */

			EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;

			ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);

		}



		/*
@@ -1794,7 +1794,7 @@ static int ext4_journalled_write_end(struct file *file, 
	new_i_size = pos + copied;

	if (new_i_size > inode->i_size)

		i_size_write(inode, pos+copied);

	EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;

	ext4_set_inode_state(inode, EXT4_STATE_JDATA);

	if (new_i_size > EXT4_I(inode)->i_disksize) {

		ext4_update_i_disksize(inode, new_i_size);

		ret2 = ext4_mark_inode_dirty(handle, inode);
@@ -2632,7 +2632,7 @@ static int __ext4_journalled_writepage(struct page *page, 
		ret = err;



	walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);

	EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;

	ext4_set_inode_state(inode, EXT4_STATE_JDATA);

out:

	return ret;

}
@@ -3303,7 +3303,8 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block) 
		filemap_write_and_wait(mapping);

	}



	if (EXT4_JOURNAL(inode) && EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {

	if (EXT4_JOURNAL(inode) &&

	    ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {

		/*

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

		 * bmap on dirty files is expected to be extremely rare:
@@ -3322,7 +3323,7 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block) 
		 * everything they get.

		 */



		EXT4_I(inode)->i_state &= ~EXT4_STATE_JDATA;

		ext4_clear_inode_state(inode, EXT4_STATE_JDATA);

		journal = EXT4_JOURNAL(inode);

		jbd2_journal_lock_updates(journal);

		err = jbd2_journal_flush(journal);
@@ -3790,7 +3791,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb, 
		if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {

			ext4_free_io_end(iocb->private);

			iocb->private = NULL;

		} else if (ret > 0 && (EXT4_I(inode)->i_state &

		} else if (ret > 0 && ext4_test_inode_state(inode,

						EXT4_STATE_DIO_UNWRITTEN)) {

			int err;

			/*
@@ -3801,7 +3802,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb, 
							     offset, ret);

			if (err < 0)

				ret = err;

			EXT4_I(inode)->i_state &= ~EXT4_STATE_DIO_UNWRITTEN;

			ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);

		}

		return ret;

	}
@@ -4457,7 +4458,7 @@ void ext4_truncate(struct inode *inode) 
		return;



	if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))

		ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;

		ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);



	if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {

		ext4_ext_truncate(inode);
@@ -4743,7 +4744,7 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) 
{

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

	return __ext4_get_inode_loc(inode, iloc,

		!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR));

		!ext4_test_inode_state(inode, EXT4_STATE_XATTR));

}



void ext4_set_inode_flags(struct inode *inode)
@@ -4837,7 +4838,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
	}

	inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);



	ei->i_state = 0;

	ei->i_state_flags = 0;

	ei->i_dir_start_lookup = 0;

	ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);

	/* We now have enough fields to check if the inode was active or not.
@@ -4920,7 +4921,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) 
					EXT4_GOOD_OLD_INODE_SIZE +

					ei->i_extra_isize;

			if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC))

				ei->i_state |= EXT4_STATE_XATTR;

				ext4_set_inode_state(inode, EXT4_STATE_XATTR);

		}

	} else

		ei->i_extra_isize = 0;
@@ -5060,7 +5061,7 @@ static int ext4_do_update_inode(handle_t *handle, 


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

	 * initialise them to zero for new inodes. */

	if (ei->i_state & EXT4_STATE_NEW)

	if (ext4_test_inode_state(inode, EXT4_STATE_NEW))

		memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);



	ext4_get_inode_flags(ei);
@@ -5156,7 +5157,7 @@ static int ext4_do_update_inode(handle_t *handle, 
	rc = ext4_handle_dirty_metadata(handle, inode, bh);

	if (!err)

		err = rc;

	ei->i_state &= ~EXT4_STATE_NEW;

	ext4_clear_inode_state(inode, EXT4_STATE_NEW);



	ext4_update_inode_fsync_trans(handle, inode, 0);

out_brelse:
@@ -5580,7 +5581,7 @@ static int ext4_expand_extra_isize(struct inode *inode, 
	entry = IFIRST(header);



	/* No extended attributes present */

	if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR) ||

	if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||

	    header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {

		memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,

			new_extra_isize);
@@ -5625,7 +5626,7 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) 
	err = ext4_reserve_inode_write(handle, inode, &iloc);

	if (ext4_handle_valid(handle) &&

	    EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&

	    !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) {

	    !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {

		/*

		 * We need extra buffer credits since we may write into EA block

		 * with this same handle. If journal_extend fails, then it will
@@ -5639,7 +5640,8 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) 
						      sbi->s_want_extra_isize,

						      iloc, handle);

			if (ret) {

				EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;

				ext4_set_inode_state(inode,

						     EXT4_STATE_NO_EXPAND);

				if (mnt_count !=

					le16_to_cpu(sbi->s_es->s_mnt_count)) {

					ext4_warning(inode->i_sb, __func__,