From: Theodore Ts'o Date: Wed, 3 Apr 2013 16:47:17 +0000 (-0400) Subject: ext4: refactor truncate code X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=819c4920b7e60ecfd6f0f61d890af4cdf3873d18;p=openwrt%2Fstaging%2Fblogic.git ext4: refactor truncate code Move common code in ext4_ind_truncate() and ext4_ext_truncate() into ext4_truncate(). This saves over 60 lines of code. Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 0649253804c4..d05ba3886f33 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2109,7 +2109,7 @@ extern ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb, unsigned long nr_segs); extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock); extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk); -extern void ext4_ind_truncate(struct inode *inode); +extern void ext4_ind_truncate(handle_t *, struct inode *inode); extern int ext4_free_hole_blocks(handle_t *handle, struct inode *inode, ext4_lblk_t first, ext4_lblk_t stop); @@ -2575,7 +2575,7 @@ extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk); extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, int flags); -extern void ext4_ext_truncate(struct inode *); +extern void ext4_ext_truncate(handle_t *, struct inode *); extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, ext4_lblk_t end); extern void ext4_ext_init(struct super_block *); diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index d58365e40df7..cbbe8a4deac6 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4257,47 +4257,12 @@ out3: return err ? err : allocated; } -void ext4_ext_truncate(struct inode *inode) +void ext4_ext_truncate(handle_t *handle, struct inode *inode) { - struct address_space *mapping = inode->i_mapping; struct super_block *sb = inode->i_sb; ext4_lblk_t last_block; - handle_t *handle; - loff_t page_len; int err = 0; - /* - * finish any pending end_io work so we won't run the risk of - * converting any truncated blocks to initialized later - */ - ext4_flush_unwritten_io(inode); - - /* - * probably first extent we're gonna free will be last in block - */ - err = ext4_writepage_trans_blocks(inode); - handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, err); - if (IS_ERR(handle)) - return; - - if (inode->i_size % PAGE_CACHE_SIZE != 0) { - page_len = PAGE_CACHE_SIZE - - (inode->i_size & (PAGE_CACHE_SIZE - 1)); - - err = ext4_discard_partial_page_buffers(handle, - mapping, inode->i_size, page_len, 0); - - if (err) - goto out_stop; - } - - if (ext4_orphan_add(handle, inode)) - goto out_stop; - - down_write(&EXT4_I(inode)->i_data_sem); - - ext4_discard_preallocations(inode); - /* * TODO: optimization is possible here. * Probably we need not scan at all, @@ -4313,29 +4278,6 @@ void ext4_ext_truncate(struct inode *inode) err = ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block); err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1); - - /* In a multi-transaction truncate, we only make the final - * transaction synchronous. - */ - if (IS_SYNC(inode)) - ext4_handle_sync(handle); - - up_write(&EXT4_I(inode)->i_data_sem); - -out_stop: - /* - * If this was a simple ftruncate() and the file will remain alive, - * then we need to clear up the orphan record which we created above. - * However, if this was a real unlink then we were called by - * ext4_delete_inode(), and we allow that function to clean up the - * orphan info for us. - */ - if (inode->i_nlink) - ext4_orphan_del(handle, inode); - - inode->i_mtime = inode->i_ctime = ext4_current_time(inode); - ext4_mark_inode_dirty(handle, inode); - ext4_journal_stop(handle); } static void ext4_falloc_update_inode(struct inode *inode, diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index d8846779f4ea..98be6f697463 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -806,26 +806,9 @@ int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk) * be able to restart the transaction at a conventient checkpoint to make * sure we don't overflow the journal. * - * start_transaction gets us a new handle for a truncate transaction, - * and extend_transaction tries to extend the existing one a bit. If + * Try to extend this transaction for the purposes of truncation. If * extend fails, we need to propagate the failure up and restart the * transaction in the top-level truncate loop. --sct - */ -static handle_t *start_transaction(struct inode *inode) -{ - handle_t *result; - - result = ext4_journal_start(inode, EXT4_HT_TRUNCATE, - ext4_blocks_for_truncate(inode)); - if (!IS_ERR(result)) - return result; - - ext4_std_error(inode->i_sb, PTR_ERR(result)); - return result; -} - -/* - * Try to extend this transaction for the purposes of truncation. * * Returns 0 if we managed to create more room. If we can't create more * room, and the transaction must be restarted we return 1. @@ -1218,68 +1201,30 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode, } } -void ext4_ind_truncate(struct inode *inode) +void ext4_ind_truncate(handle_t *handle, struct inode *inode) { - handle_t *handle; struct ext4_inode_info *ei = EXT4_I(inode); __le32 *i_data = ei->i_data; int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); - struct address_space *mapping = inode->i_mapping; ext4_lblk_t offsets[4]; Indirect chain[4]; Indirect *partial; __le32 nr = 0; int n = 0; ext4_lblk_t last_block, max_block; - loff_t page_len; unsigned blocksize = inode->i_sb->s_blocksize; - int err; - - handle = start_transaction(inode); - if (IS_ERR(handle)) - return; /* AKPM: return what? */ last_block = (inode->i_size + blocksize-1) >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1) >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); - if (inode->i_size % PAGE_CACHE_SIZE != 0) { - page_len = PAGE_CACHE_SIZE - - (inode->i_size & (PAGE_CACHE_SIZE - 1)); - - err = ext4_discard_partial_page_buffers(handle, - mapping, inode->i_size, page_len, 0); - - if (err) - goto out_stop; - } - if (last_block != max_block) { n = ext4_block_to_path(inode, last_block, offsets, NULL); if (n == 0) - goto out_stop; /* error */ + return; } - /* - * OK. This truncate is going to happen. We add the inode to the - * orphan list, so that if this truncate spans multiple transactions, - * and we crash, we will resume the truncate when the filesystem - * recovers. It also marks the inode dirty, to catch the new size. - * - * Implication: the file must always be in a sane, consistent - * truncatable state while each transaction commits. - */ - if (ext4_orphan_add(handle, inode)) - goto out_stop; - - /* - * From here we block out all ext4_get_block() callers who want to - * modify the block allocation tree. - */ - down_write(&ei->i_data_sem); - - ext4_discard_preallocations(inode); ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block); /* @@ -1296,7 +1241,7 @@ void ext4_ind_truncate(struct inode *inode) * It is unnecessary to free any data blocks if last_block is * equal to the indirect block limit. */ - goto out_unlock; + return; } else if (n == 1) { /* direct blocks */ ext4_free_data(handle, inode, NULL, i_data+offsets[0], i_data + EXT4_NDIR_BLOCKS); @@ -1356,31 +1301,6 @@ do_indirects: case EXT4_TIND_BLOCK: ; } - -out_unlock: - up_write(&ei->i_data_sem); - inode->i_mtime = inode->i_ctime = ext4_current_time(inode); - ext4_mark_inode_dirty(handle, inode); - - /* - * In a multi-transaction truncate, we only make the final transaction - * synchronous - */ - if (IS_SYNC(inode)) - ext4_handle_sync(handle); -out_stop: - /* - * If this was a simple ftruncate(), and the file will remain alive - * then we need to clear up the orphan record which we created above. - * However, if this was a real unlink then we were called by - * ext4_delete_inode(), and we allow that function to clean up the - * orphan info for us. - */ - if (inode->i_nlink) - ext4_orphan_del(handle, inode); - - ext4_journal_stop(handle); - trace_ext4_truncate_exit(inode); } static int free_hole_blocks(handle_t *handle, struct inode *inode, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 9bda50aa34e2..49c80e4ac5ac 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3738,9 +3738,9 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) stop_block); ext4_discard_preallocations(inode); + up_write(&EXT4_I(inode)->i_data_sem); if (IS_SYNC(inode)) ext4_handle_sync(handle); - up_write(&EXT4_I(inode)->i_data_sem); inode->i_mtime = inode->i_ctime = ext4_current_time(inode); ext4_mark_inode_dirty(handle, inode); out_stop: @@ -3782,6 +3782,12 @@ out_mutex: */ void ext4_truncate(struct inode *inode) { + struct ext4_inode_info *ei = EXT4_I(inode); + unsigned int credits; + handle_t *handle; + struct address_space *mapping = inode->i_mapping; + loff_t page_len; + trace_ext4_truncate_enter(inode); if (!ext4_can_truncate(inode)) @@ -3800,10 +3806,72 @@ void ext4_truncate(struct inode *inode) return; } + /* + * finish any pending end_io work so we won't run the risk of + * converting any truncated blocks to initialized later + */ + ext4_flush_unwritten_io(inode); + + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + credits = ext4_writepage_trans_blocks(inode); + else + credits = ext4_blocks_for_truncate(inode); + + handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); + if (IS_ERR(handle)) { + ext4_std_error(inode->i_sb, PTR_ERR(handle)); + return; + } + + if (inode->i_size % PAGE_CACHE_SIZE != 0) { + page_len = PAGE_CACHE_SIZE - + (inode->i_size & (PAGE_CACHE_SIZE - 1)); + + if (ext4_discard_partial_page_buffers(handle, + mapping, inode->i_size, page_len, 0)) + goto out_stop; + } + + /* + * We add the inode to the orphan list, so that if this + * truncate spans multiple transactions, and we crash, we will + * resume the truncate when the filesystem recovers. It also + * marks the inode dirty, to catch the new size. + * + * Implication: the file must always be in a sane, consistent + * truncatable state while each transaction commits. + */ + if (ext4_orphan_add(handle, inode)) + goto out_stop; + + down_write(&EXT4_I(inode)->i_data_sem); + + ext4_discard_preallocations(inode); + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) - ext4_ext_truncate(inode); + ext4_ext_truncate(handle, inode); else - ext4_ind_truncate(inode); + ext4_ind_truncate(handle, inode); + + up_write(&ei->i_data_sem); + + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + +out_stop: + /* + * If this was a simple ftruncate() and the file will remain alive, + * then we need to clear up the orphan record which we created above. + * However, if this was a real unlink then we were called by + * ext4_delete_inode(), and we allow that function to clean up the + * orphan info for us. + */ + if (inode->i_nlink) + ext4_orphan_del(handle, inode); + + inode->i_mtime = inode->i_ctime = ext4_current_time(inode); + ext4_mark_inode_dirty(handle, inode); + ext4_journal_stop(handle); trace_ext4_truncate_exit(inode); }