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: Jan Kara <jack@suse.cz>

5 files changed, 44 insertions, 27 deletions

diff --git a/fs/ext3/file.c b/fs/ext3/file.c
index 388bbdfa0b4e..a86d3302cdc2 100644
--- a/fs/ext3/file.c
+++ b/fs/ext3/file.c
@@ -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) &&
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 455e6e6e5cb9..44b53386ab8b 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -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:
diff --git a/fs/ext3/xattr.c b/fs/ext3/xattr.c
index 66895ccf76c7..2d2fb2a85961 100644
--- a/fs/ext3/xattr.c
+++ b/fs/ext3/xattr.c
@@ -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);
diff --git a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h
index 6b049030fbe6..e6590f8f0b3c 100644
--- a/include/linux/ext3_fs.h
+++ b/include/linux/ext3_fs.h
@@ -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
diff --git a/include/linux/ext3_fs_i.h b/include/linux/ext3_fs_i.h
index 93e7428156ba..7679acdb519a 100644
--- a/include/linux/ext3_fs_i.h
+++ b/include/linux/ext3_fs_i.h
@@ -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;