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>

7 files changed, 71 insertions, 51 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 307ecd13a762..ffe1334c891e 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -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
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index c56877972b0e..54616157c0f3 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -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 */
 
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 9630583cef28..f6071ce0b155 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -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) &&
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index f3624ead4f6c..2fab5adae1e2 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -1029,7 +1029,8 @@ got:
         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;
 
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__,
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 81415814b00b..46a4101e0aec 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -365,12 +365,12 @@ static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
          * happened after we started the migrate. We need to
          * fail the migrate
          */
-        if (!(EXT4_I(inode)->i_state & EXT4_STATE_EXT_MIGRATE)) {
+        if (!ext4_test_inode_state(inode, EXT4_STATE_EXT_MIGRATE)) {
                 retval = -EAGAIN;
                 up_write(&EXT4_I(inode)->i_data_sem);
                 goto err_out;
         } else
-                EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;
+                ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
         /*
          * We have the extent map build with the tmp inode.
          * Now copy the i_data across
@@ -533,7 +533,7 @@ int ext4_ext_migrate(struct inode *inode)
          * allocation.
          */
         down_read((&EXT4_I(inode)->i_data_sem));
-        EXT4_I(inode)->i_state |= EXT4_STATE_EXT_MIGRATE;
+        ext4_set_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
         up_read((&EXT4_I(inode)->i_data_sem));
 
         handle = ext4_journal_start(inode, 1);
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index f3a2f7ed45aa..c619a7ea670d 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -267,7 +267,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
         void *end;
         int error;
 
-        if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR))
+        if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
                 return -ENODATA;
         error = ext4_get_inode_loc(inode, &iloc);
         if (error)
@@ -396,7 +396,7 @@ ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
         void *end;
         int error;
 
-        if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR))
+        if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
                 return 0;
         error = ext4_get_inode_loc(inode, &iloc);
         if (error)
@@ -908,7 +908,7 @@ ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
         is->s.base = is->s.first = IFIRST(header);
         is->s.here = is->s.first;
         is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
-        if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
+        if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
                 error = ext4_xattr_check_names(IFIRST(header), is->s.end);
                 if (error)
                         return error;
@@ -940,10 +940,10 @@ ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
         header = IHDR(inode, ext4_raw_inode(&is->iloc));
         if (!IS_LAST_ENTRY(s->first)) {
                 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
-                EXT4_I(inode)->i_state |= EXT4_STATE_XATTR;
+                ext4_set_inode_state(inode, EXT4_STATE_XATTR);
         } else {
                 header->h_magic = cpu_to_le32(0);
-                EXT4_I(inode)->i_state &= ~EXT4_STATE_XATTR;
+                ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
         }
         return 0;
 }
@@ -986,8 +986,8 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
         if (strlen(name) > 255)
                 return -ERANGE;
         down_write(&EXT4_I(inode)->xattr_sem);
-        no_expand = EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND;
-        EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;
+        no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
+        ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
 
         error = ext4_get_inode_loc(inode, &is.iloc);
         if (error)
@@ -997,10 +997,10 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
         if (error)
                 goto cleanup;
 
-        if (EXT4_I(inode)->i_state & EXT4_STATE_NEW) {
+        if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
                 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
                 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
-                EXT4_I(inode)->i_state &= ~EXT4_STATE_NEW;
+                ext4_clear_inode_state(inode, EXT4_STATE_NEW);
         }
 
         error = ext4_xattr_ibody_find(inode, &i, &is);
@@ -1052,7 +1052,7 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
                 ext4_xattr_update_super_block(handle, inode->i_sb);
                 inode->i_ctime = ext4_current_time(inode);
                 if (!value)
-                        EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
+                        ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
                 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
                 /*
                  * The bh is consumed by ext4_mark_iloc_dirty, even with
@@ -1067,7 +1067,7 @@ cleanup:
         brelse(is.iloc.bh);
         brelse(bs.bh);
         if (no_expand == 0)
-                EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
+                ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
         up_write(&EXT4_I(inode)->xattr_sem);
         return error;
 }