diff options
Diffstat (limited to 'fs/ext4/migrate.c')
| -rw-r--r-- | fs/ext4/migrate.c | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c index 5c1e27de775..9b4fb07d192 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) |