summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--fs/ext4/inode.c13
-rw-r--r--fs/ext4/migrate.c39
-rw-r--r--include/linux/ext4_fs.h1
3 files changed, 47 insertions, 6 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 8fab233..24a2604 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -985,6 +985,16 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
} else {
retval = ext4_get_blocks_handle(handle, inode, block,
max_blocks, bh, create, extend_disksize);
+
+ if (retval > 0 && buffer_new(bh)) {
+ /*
+ * We allocated new blocks which will result in
+ * 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;
+ }
}
up_write((&EXT4_I(inode)->i_data_sem));
return retval;
@@ -2976,7 +2986,8 @@ 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);
- raw_inode->i_flags = cpu_to_le32(ei->i_flags);
+ /* clear the migrate flag in the raw_inode */
+ raw_inode->i_flags = cpu_to_le32(ei->i_flags & ~EXT4_EXT_MIGRATE);
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 5c1e27d..9b4fb07 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -327,7 +327,7 @@ static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
}
static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
- struct inode *tmp_inode)
+ struct inode *tmp_inode)
{
int retval;
__le32 i_data[3];
@@ -339,7 +339,7 @@ static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
* i_data field of the original inode
*/
retval = ext4_journal_extend(handle, 1);
- if (retval != 0) {
+ if (retval) {
retval = ext4_journal_restart(handle, 1);
if (retval)
goto err_out;
@@ -351,6 +351,18 @@ 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
+ * happened after we started the migrate. We need to
+ * fail the migrate
+ */
+ if (!(EXT4_I(inode)->i_flags & EXT4_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;
+ /*
* We have the extent map build with the tmp inode.
* Now copy the i_data across
*/
@@ -508,6 +520,17 @@ int ext4_ext_migrate(struct inode *inode, struct file *filp,
* switch the inode format to prevent read.
*/
mutex_lock(&(inode->i_mutex));
+ /*
+ * 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.
+ */
+ down_read((&EXT4_I(inode)->i_data_sem));
+ EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags | EXT4_EXT_MIGRATE;
+ up_read((&EXT4_I(inode)->i_data_sem));
+
handle = ext4_journal_start(inode, 1);
ei = EXT4_I(inode);
@@ -559,9 +582,15 @@ err_out:
* tmp_inode
*/
free_ext_block(handle, tmp_inode);
- else
- retval = ext4_ext_swap_inode_data(handle, inode,
- tmp_inode);
+ else {
+ retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
+ if (retval)
+ /*
+ * if we fail to swap inode data free the extent
+ * details of the tmp inode
+ */
+ free_ext_block(handle, tmp_inode);
+ }
/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
if (ext4_journal_extend(handle, 1) != 0)
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index 2500325..105337c 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -231,6 +231,7 @@ struct ext4_group_desc
#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 */
OpenPOWER on IntegriCloud