diff options
| -rw-r--r-- | fs/ext4/inode.c | 13 | ||||
| -rw-r--r-- | fs/ext4/migrate.c | 39 | ||||
| -rw-r--r-- | include/linux/ext4_fs.h | 1 |
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 */ |