ext4: store EXT4_EXT_MIGRATE in i_state instead of i_flags

EXT4_EXT_MIGRATE is only intended to be used for an in-memory flag,
and the hex value assigned to it collides with FS_DIRECTIO_FL (which
is also stored in i_flags).  There's no reason for the
EXT4_EXT_MIGRATE bit to be stored in i_flags, so we switch it to use
i_state instead.

Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 2a0f75d..84e7f1d 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -268,7 +268,6 @@ struct flex_groups {
 #define EXT4_TOPDIR_FL                 0x00020000 /* Top of directory hierarchies*/
 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
 #define EXT4_EXTENTS_FL                        0x00080000 /* Inode uses extents */
-#define EXT4_EXT_MIGRATE               0x00100000 /* Inode is migrating */
 #define EXT4_RESERVED_FL               0x80000000 /* reserved for ext4 lib */
 
 #define EXT4_FL_USER_VISIBLE           0x000BDFFF /* User visible flags */
@@ -306,6 +305,7 @@ static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 #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 */
 
 /* Used to pass group descriptor data when online resize is done */
 struct ext4_new_group_input {

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 5a89792..a5b4ce4 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1255,8 +1255,7 @@ 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_flags = EXT4_I(inode)->i_flags &
-                                                       ~EXT4_EXT_MIGRATE;
+                       EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;
                }
        }
 
@@ -4596,8 +4595,7 @@ static int ext4_do_update_inode(handle_t *handle,
        if (ext4_inode_blocks_set(handle, raw_inode, ei))
                goto out_brelse;
        raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
-       /* clear the migrate flag in the raw_inode */
-       raw_inode->i_flags = cpu_to_le32(ei->i_flags & ~EXT4_EXT_MIGRATE);
+       raw_inode->i_flags = cpu_to_le32(ei->i_flags);
        if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
            cpu_to_le32(EXT4_OS_HURD))
                raw_inode->i_file_acl_high =

diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 05361ad..bf519f2 100644 (file)
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -353,17 +353,16 @@ static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
 
        down_write(&EXT4_I(inode)->i_data_sem);
        /*
-        * if EXT4_EXT_MIGRATE is cleared a block allocation
+        * if EXT4_STATE_EXT_MIGRATE is cleared a block allocation
         * happened after we started the migrate. We need to
         * fail the migrate
         */
-       if (!(EXT4_I(inode)->i_flags & EXT4_EXT_MIGRATE)) {
+       if (!(EXT4_I(inode)->i_state & EXT4_STATE_EXT_MIGRATE)) {
                retval = -EAGAIN;
                up_write(&EXT4_I(inode)->i_data_sem);
                goto err_out;
        } else
-               EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags &
-                                                       ~EXT4_EXT_MIGRATE;
+               EXT4_I(inode)->i_state &= ~EXT4_STATE_EXT_MIGRATE;
        /*
         * We have the extent map build with the tmp inode.
         * Now copy the i_data across
@@ -517,14 +516,15 @@ int ext4_ext_migrate(struct inode *inode)
         * when we add extents we extent the journal
         */
        /*
-        * Even though we take i_mutex we can still cause block allocation
-        * via mmap write to holes. If we have allocated new blocks we fail
-        * migrate.  New block allocation will clear EXT4_EXT_MIGRATE flag.
-        * The flag is updated with i_data_sem held to prevent racing with
-        * block allocation.
+        * Even though we take i_mutex we can still cause block
+        * allocation via mmap write to holes. If we have allocated
+        * new blocks we fail migrate.  New block allocation will
+        * clear EXT4_STATE_EXT_MIGRATE flag.  The flag is updated
+        * with i_data_sem held to prevent racing with block
+        * allocation.
         */
        down_read((&EXT4_I(inode)->i_data_sem));
-       EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags | EXT4_EXT_MIGRATE;
+       EXT4_I(inode)->i_state |= EXT4_STATE_EXT_MIGRATE;
        up_read((&EXT4_I(inode)->i_data_sem));
 
        handle = ext4_journal_start(inode, 1);