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 1a3d7b232cd7..3e530119d7f0 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__,