Commit 202ee5df authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: add a new spinlock i_raw_lock to protect the ext4's raw inode 



To avoid potential data races, use a spinlock which protects the raw
(on-disk) inode.

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
parent f5ccfe1d

fs/ext4/ext4.h

+2 −0
Original line number Diff line number Diff line
@@ -875,6 +875,8 @@ struct ext4_inode_info { 
	struct inode vfs_inode;

	struct jbd2_inode *jinode;



	spinlock_t i_raw_lock;	/* protects updates to the raw inode */



	/*

	 * File creation time. Its function is same as that of

	 * struct timespec i_{a,c,m}time in the generic inode.

fs/ext4/inode.c

+22 −19
Original line number Diff line number Diff line
@@ -4305,12 +4305,15 @@ static int ext4_do_update_inode(handle_t *handle, 
	struct ext4_inode *raw_inode = ext4_raw_inode(iloc);

	struct ext4_inode_info *ei = EXT4_I(inode);

	struct buffer_head *bh = iloc->bh;

	struct super_block *sb = inode->i_sb;

	int err = 0, rc, block;

	int need_datasync = 0;

	int need_datasync = 0, set_large_file = 0;

	uid_t i_uid;

	gid_t i_gid;



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

	spin_lock(&ei->i_raw_lock);



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

	 * initialise them to zero for new inodes. */

	if (ext4_test_inode_state(inode, EXT4_STATE_NEW))

		memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
@@ -4348,8 +4351,10 @@ static int ext4_do_update_inode(handle_t *handle, 
	EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);

	EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);



	if (ext4_inode_blocks_set(handle, raw_inode, ei))

	if (ext4_inode_blocks_set(handle, raw_inode, ei)) {

		spin_unlock(&ei->i_raw_lock);

		goto out_brelse;

	}

	raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);

	raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);

	if (likely(!test_opt2(inode->i_sb, HURD_COMPAT)))
@@ -4361,24 +4366,11 @@ static int ext4_do_update_inode(handle_t *handle, 
		need_datasync = 1;

	}

	if (ei->i_disksize > 0x7fffffffULL) {

		struct super_block *sb = inode->i_sb;

		if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,

				EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||

				EXT4_SB(sb)->s_es->s_rev_level ==

				cpu_to_le32(EXT4_GOOD_OLD_REV)) {

			/* If this is the first large file

			 * created, add a flag to the superblock.

			 */

			err = ext4_journal_get_write_access(handle,

					EXT4_SB(sb)->s_sbh);

			if (err)

				goto out_brelse;

			ext4_update_dynamic_rev(sb);

			EXT4_SET_RO_COMPAT_FEATURE(sb,

					EXT4_FEATURE_RO_COMPAT_LARGE_FILE);

			ext4_handle_sync(handle);

			err = ext4_handle_dirty_super(handle, sb);

		}

		    cpu_to_le32(EXT4_GOOD_OLD_REV))

			set_large_file = 1;

	}

	raw_inode->i_generation = cpu_to_le32(inode->i_generation);

	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
@@ -4410,12 +4402,23 @@ static int ext4_do_update_inode(handle_t *handle, 


	ext4_inode_csum_set(inode, raw_inode, ei);



	spin_unlock(&ei->i_raw_lock);



	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");

	rc = ext4_handle_dirty_metadata(handle, NULL, bh);

	if (!err)

		err = rc;

	ext4_clear_inode_state(inode, EXT4_STATE_NEW);



	if (set_large_file) {

		err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);

		if (err)

			goto out_brelse;

		ext4_update_dynamic_rev(sb);

		EXT4_SET_RO_COMPAT_FEATURE(sb,

					   EXT4_FEATURE_RO_COMPAT_LARGE_FILE);

		ext4_handle_sync(handle);

		err = ext4_handle_dirty_super(handle, sb);

	}

	ext4_update_inode_fsync_trans(handle, inode, need_datasync);

out_brelse:

	brelse(bh);

fs/ext4/super.c

+1 −0
Original line number Diff line number Diff line
@@ -879,6 +879,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb) 
		return NULL;



	ei->vfs_inode.i_version = 1;

	spin_lock_init(&ei->i_raw_lock);

	INIT_LIST_HEAD(&ei->i_prealloc_list);

	spin_lock_init(&ei->i_prealloc_lock);

	ext4_es_init_tree(&ei->i_es_tree);