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: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 20 insertions, 18 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 1a3d7b2..3e53011 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -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);
@@ -3790,8 +3791,8 @@ 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 &
-				       EXT4_STATE_DIO_UNWRITTEN)) {
+		} else if (ret > 0 && ext4_test_inode_state(inode,
+						EXT4_STATE_DIO_UNWRITTEN)) {
 			int err;
 			/*
 			 * for non AIO case, since the IO is already
@@ -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:
@@ -5580,8 +5581,8 @@ 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) ||
-		header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
+	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);
 		EXT4_I(inode)->i_extra_isize = 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__,