From: Akira Fujita Subject: [RFC][PATCH 9/12]ext4: Add the EXT4_IOC_RESERVE_BLOCK ioctl Date: Sat, 27 Sep 2008 16:27:12 +0900 Message-ID: <48DDE050.6070602@rs.jp.nec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org To: linux-ext4@vger.kernel.org Return-path: Received: from TYO202.gate.nec.co.jp ([202.32.8.206]:57377 "EHLO tyo202.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752017AbYI0H1O (ORCPT ); Sat, 27 Sep 2008 03:27:14 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: ext4: online defrag -- Add the EXT4_IOC_RESERVE_BLOCK ioctl. From: Akira Fujita The EXT4_IOC_RESERVE_BLOCK ioctl reserves the specified contiguous free space with ext4 block reservation function. This ioctl is used only in the force defrag (-f). The block reservation and the multi-block allocation are mutually exclusive, so this ioctl will go away in the next version. Signed-off-by: Akira Fujita Signed-off-by: Takashi Sato --- fs/ext4/balloc.c | 10 ++-- fs/ext4/defrag.c | 196 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/ext4/ext4.h | 10 +++ fs/ext4/ioctl.c | 3 +- 4 files changed, 213 insertions(+), 6 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 64ec04c..2344a96 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -433,7 +433,7 @@ restart: * If the goal block is within the reservation window, return 1; * otherwise, return 0; */ -static int +int goal_in_my_reservation(struct ext4_reserve_window *rsv, ext4_grpblk_t grp_goal, ext4_group_t group, struct super_block *sb) { @@ -538,7 +538,7 @@ void ext4_rsv_window_add(struct super_block *sb, * from the filesystem reservation window rb tree. Must be called with * rsv_lock hold. */ -static void rsv_window_remove(struct super_block *sb, +void rsv_window_remove(struct super_block *sb, struct ext4_reserve_window_node *rsv) { rsv->rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED; @@ -553,7 +553,7 @@ static void rsv_window_remove(struct super_block *sb, * * returns 1 if the end block is EXT4_RESERVE_WINDOW_NOT_ALLOCATED. */ -static inline int rsv_is_empty(struct ext4_reserve_window *rsv) +inline int rsv_is_empty(struct ext4_reserve_window *rsv) { /* a valid reservation end block could not be 0 */ return rsv->_rsv_end == EXT4_RESERVE_WINDOW_NOT_ALLOCATED; @@ -1289,7 +1289,7 @@ static int find_next_reservable_window( * @bitmap_bh: the block group block bitmap * */ -static int alloc_new_reservation(struct ext4_reserve_window_node *my_rsv, +int alloc_new_reservation(struct ext4_reserve_window_node *my_rsv, ext4_grpblk_t grp_goal, struct super_block *sb, ext4_group_t group, struct buffer_head *bitmap_bh) { @@ -1433,7 +1433,7 @@ retry: * expand the reservation window size if necessary on a best-effort * basis before ext4_new_blocks() tries to allocate blocks, */ -static void try_to_extend_reservation(struct ext4_reserve_window_node *my_rsv, +void try_to_extend_reservation(struct ext4_reserve_window_node *my_rsv, struct super_block *sb, int size) { struct ext4_reserve_window_node *next_rsv; diff --git a/fs/ext4/defrag.c b/fs/ext4/defrag.c index f7c99de..26fb4a6 100644 --- a/fs/ext4/defrag.c +++ b/fs/ext4/defrag.c @@ -193,6 +193,193 @@ out: } /** + * ext4_defrag_reserve_blocks - Reserve blocks for defrag + * + * @org_inode: original inode + * @goal: the goal offset of the block reservation + * @len: blocks count we need to reserve + * + * This function returns 0 if succeed, otherwise returns error value. + */ + +static int +ext4_defrag_reserve_blocks(struct inode *org_inode, ext4_fsblk_t goal, int len) +{ + struct super_block *sb = NULL; + handle_t *handle; + struct buffer_head *bitmap_bh = NULL; + struct ext4_block_alloc_info *block_i; + struct ext4_reserve_window_node *my_rsv = NULL; + unsigned short windowsz = 0; + ext4_group_t group_no; + ext4_grpblk_t grp_target_blk; + int err = 0; + + down_write(&EXT4_I(org_inode)->i_data_sem); + + handle = ext4_journal_start(org_inode, EXT4_RESERVE_TRANS_BLOCKS); + if (IS_ERR(handle)) { + err = PTR_ERR(handle); + handle = NULL; + goto out; + } + + if (S_ISREG(org_inode->i_mode) && + !EXT4_I(org_inode)->i_block_alloc_info) { + ext4_init_block_alloc_info(org_inode); + } else if (!S_ISREG(org_inode->i_mode)) { + printk(KERN_ERR "ext4 defrag: Invalid file type\n"); + err = -EINVAL; + goto out; + } + + sb = org_inode->i_sb; + if (!sb) { + printk(KERN_ERR "ext4 defrag: Non-existent device\n"); + err = -ENXIO; + goto out; + } + ext4_get_group_no_and_offset(sb, goal, &group_no, + &grp_target_blk); + + block_i = EXT4_I(org_inode)->i_block_alloc_info; + /* Block reservation should be enabled */ + BUG_ON(!block_i); + + windowsz = block_i->rsv_window_node.rsv_goal_size; + /* Goal size should be set */ + BUG_ON(!windowsz); + + my_rsv = &block_i->rsv_window_node; + + bitmap_bh = ext4_read_block_bitmap(sb, group_no); + if (!bitmap_bh) { + err = -ENOSPC; + goto out; + } + + BUFFER_TRACE(bitmap_bh, "get undo access for new block"); + err = ext4_journal_get_undo_access(handle, bitmap_bh); + if (err) + goto out; + + err = alloc_new_reservation(my_rsv, grp_target_blk, sb, + group_no, bitmap_bh); + if (err < 0) { + printk(KERN_ERR "ext4 defrag: Block reservation failed." + "offset [%d], bg[%lu]\n", grp_target_blk, group_no); + ext4_discard_reservation(org_inode); + goto out; + } else if (len > EXT4_DEFAULT_RESERVE_BLOCKS) { + try_to_extend_reservation(my_rsv, sb, + len - EXT4_DEFAULT_RESERVE_BLOCKS); + } + +out: + up_write(&EXT4_I(org_inode)->i_data_sem); + ext4_journal_release_buffer(handle, bitmap_bh); + brelse(bitmap_bh); + + if (handle) + ext4_journal_stop(handle); + + return err; +} + +/** + * ext4_defrag_block_within_rsv - Is target extent reserved ? + * + * @org_inode: original inode + * @ex_start: physical block offset of the extent which already moved + * @ex_len: block length of the extent + * + * This function returns 0 if succeed, otherwise returns error value. + */ +static int +ext4_defrag_block_within_rsv(struct inode *org_inode, ext4_fsblk_t ex_start, + int ex_len) +{ + struct super_block *sb = org_inode->i_sb; + struct ext4_block_alloc_info *block_i; + ext4_group_t group_no; + ext4_grpblk_t grp_blk; + struct ext4_reserve_window_node *rsv; + + block_i = EXT4_I(org_inode)->i_block_alloc_info; + /* Block reservation should be enabled */ + BUG_ON(!block_i); + + /* Goal size should be set */ + BUG_ON(!block_i->rsv_window_node.rsv_goal_size); + + rsv = &block_i->rsv_window_node; + if (rsv_is_empty(&rsv->rsv_window)) { + printk(KERN_ERR "ext4 defrag: Reservation window is empty\n"); + return -ENOSPC; + } + + ext4_get_group_no_and_offset(sb, ex_start, &group_no, &grp_blk); + + if (!goal_in_my_reservation(&rsv->rsv_window, grp_blk, group_no, sb) + || !goal_in_my_reservation(&rsv->rsv_window, + grp_blk + ex_len - 1, group_no, sb)){ + /* Goal blocks are not in the reservation window */ + printk(KERN_ERR "ext4 defrag: %d or %d in bg %lu is " + "not in rsv_window\n", grp_blk, + grp_blk + ex_len - 1, group_no); + return -ENOSPC; + } + return 0; +} + +/* + * ext4_defrag_reserve_fblocks - + * Reserve free blocks with ext4_defrag_reserve_blocks + * + * @org_inode: original inode to get a block group number + * @ext_info: freeblocks distribution which stored extent-like style + * @ext_info->ext[]: an array of struct ext4_extents_data + * + * This function returns 0 if succeed, otherwise returns error value. + */ +static int +ext4_defrag_reserve_fblocks(struct inode *org_inode, + struct ext4_extents_info *ext_info) +{ + ext4_fsblk_t ex_start = 0; + int i, len, ret; + + for (i = 0; i < ext_info->entries; i++) { + ex_start = ext_info->ext[i].start; + len = ext_info->ext[i].len; + + ret = ext4_defrag_reserve_blocks(org_inode, ex_start, len); + if (ret < 0) { + printk(KERN_ERR "ext4 defrag: " + "Block reservation failed. offset [%llu], " + "length [%d]\n", ex_start, len); + goto err; + } + + /* Confirm that blocks are in the reservation window */ + ret = ext4_defrag_block_within_rsv(org_inode, ex_start, len); + if (ret < 0) { + printk(KERN_ERR "ext4 defrag: " + "Reservation window is not set. " + "offset [%llu], length [%d]\n", ex_start, len); + goto err; + } + } + return ret; + +err: + down_write(&EXT4_I(org_inode)->i_data_sem); + ext4_discard_reservation(org_inode); + up_write(&EXT4_I(org_inode)->i_data_sem); + return ret; +} + +/** * ext4_defrag_fblocks_distribution - Search free blocks distribution * * @org_inode: original inode @@ -342,6 +529,15 @@ int ext4_defrag_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, } else if (cmd == EXT4_IOC_FIEMAP_INO) { err = ext4_defrag_fiemap_ino(filp, arg); + } else if (cmd == EXT4_IOC_RESERVE_BLOCK) { + struct ext4_extents_info ext_info; + + if (copy_from_user(&ext_info, + (struct ext4_extents_info __user *)arg, + sizeof(ext_info))) + return -EFAULT; + + err = ext4_defrag_reserve_fblocks(inode, &ext_info); } else if (cmd == EXT4_IOC_DEFRAG) { struct ext4_ext_defrag_data defrag; struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 8d008c8..eef7885 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -307,6 +307,7 @@ struct ext4_new_group_data { #define EXT4_IOC_GROUP_INFO _IOW('f', 17, struct ext4_group_data_info) #define EXT4_IOC_FREE_BLOCKS_INFO _IOW('f', 18, struct ext4_extents_info) #define EXT4_IOC_FIEMAP_INO _IOW('f', 19, struct fiemap_ino) +#define EXT4_IOC_RESERVE_BLOCK _IOW('f', 20, struct ext4_extents_info) /* * ioctl commands in 32 bit emulation @@ -1046,8 +1047,17 @@ extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb, extern int ext4_should_retry_alloc(struct super_block *sb, int *retries); extern void ext4_init_block_alloc_info(struct inode *); extern void ext4_rsv_window_add(struct super_block *sb, struct ext4_reserve_window_node *rsv); +extern void try_to_extend_reservation(struct ext4_reserve_window_node *, + struct super_block *, int); +extern int alloc_new_reservation(struct ext4_reserve_window_node *, + ext4_grpblk_t, struct super_block *, + ext4_group_t, struct buffer_head *); extern ext4_grpblk_t bitmap_search_next_usable_block(ext4_grpblk_t, struct buffer_head *, ext4_grpblk_t); +extern int rsv_is_empty(struct ext4_reserve_window *rsv); +extern int goal_in_my_reservation(struct ext4_reserve_window *rsv, + ext4_grpblk_t grp_goal, ext4_group_t group, + struct super_block *sb); /* dir.c */ extern int ext4_check_dir_entry(const char *, struct inode *, diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index a0e4915..9c992d8 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -260,7 +260,8 @@ setversion_out: case EXT4_IOC_DEFRAG: case EXT4_IOC_GROUP_INFO: case EXT4_IOC_FREE_BLOCKS_INFO: - case EXT4_IOC_FIEMAP_INO: { + case EXT4_IOC_FIEMAP_INO: + case EXT4_IOC_RESERVE_BLOCK: { return ext4_defrag_ioctl(inode, filp, cmd, arg); } case EXT4_IOC_GROUP_ADD: {