From: Zheng Liu Subject: [PATCH 7/9 v6] ext4: remove single extent cache Date: Mon, 18 Feb 2013 00:27:52 +0800 Message-ID: <1361118474-18310-8-git-send-email-wenqing.lz@taobao.com> References: <1361118474-18310-1-git-send-email-wenqing.lz@taobao.com> Cc: Zheng Liu , "Theodore Ts'o" , Jan kara To: linux-ext4@vger.kernel.org Return-path: Received: from mail-da0-f46.google.com ([209.85.210.46]:33545 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750994Ab3BQQOA (ORCPT ); Sun, 17 Feb 2013 11:14:00 -0500 Received: by mail-da0-f46.google.com with SMTP id p5so2078654dak.19 for ; Sun, 17 Feb 2013 08:14:00 -0800 (PST) In-Reply-To: <1361118474-18310-1-git-send-email-wenqing.lz@taobao.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Zheng Liu Single extent cache could be removed because we have extent status tree as a extent cache, and it would be better. Signed-off-by: Zheng Liu Cc: "Theodore Ts'o" Cc: Jan kara --- fs/ext4/ext4.h | 12 ---- fs/ext4/ext4_extents.h | 6 -- fs/ext4/extents.c | 179 +++++++++++-------------------------------------- fs/ext4/move_extent.c | 3 - fs/ext4/super.c | 1 - 5 files changed, 38 insertions(+), 163 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 8c8cd57..29bd2ef 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -812,17 +812,6 @@ do { \ #endif /* defined(__KERNEL__) || defined(__linux__) */ -/* - * storage for cached extent - * If ec_len == 0, then the cache is invalid. - * If ec_start == 0, then the cache represents a gap (null mapping) - */ -struct ext4_ext_cache { - ext4_fsblk_t ec_start; - ext4_lblk_t ec_block; - __u32 ec_len; /* must be 32bit to return holes */ -}; - #include "extents_status.h" /* @@ -889,7 +878,6 @@ struct ext4_inode_info { struct inode vfs_inode; struct jbd2_inode *jinode; - struct ext4_ext_cache i_cached_extent; /* * File creation time. Its function is same as that of * struct timespec i_{a,c,m}time in the generic inode. diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h index 487fda1..8643ff5 100644 --- a/fs/ext4/ext4_extents.h +++ b/fs/ext4/ext4_extents.h @@ -193,12 +193,6 @@ static inline unsigned short ext_depth(struct inode *inode) return le16_to_cpu(ext_inode_hdr(inode)->eh_depth); } -static inline void -ext4_ext_invalidate_cache(struct inode *inode) -{ - EXT4_I(inode)->i_cached_extent.ec_len = 0; -} - static inline void ext4_ext_mark_uninitialized(struct ext4_extent *ext) { /* We can not have an uninitialized extent of zero length! */ diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index d5161cd..55e73a9 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -112,7 +112,7 @@ static int ext4_split_extent_at(handle_t *handle, int flags); static int ext4_find_delayed_extent(struct inode *inode, - struct ext4_ext_cache *newex); + struct extent_status *newes); static int ext4_ext_truncate_extend_restart(handle_t *handle, struct inode *inode, @@ -714,7 +714,6 @@ int ext4_ext_tree_init(handle_t *handle, struct inode *inode) eh->eh_magic = EXT4_EXT_MAGIC; eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); ext4_mark_inode_dirty(handle, inode); - ext4_ext_invalidate_cache(inode); return 0; } @@ -1960,7 +1959,6 @@ cleanup: ext4_ext_drop_refs(npath); kfree(npath); } - ext4_ext_invalidate_cache(inode); return err; } @@ -1969,8 +1967,8 @@ static int ext4_fill_fiemap_extents(struct inode *inode, struct fiemap_extent_info *fieinfo) { struct ext4_ext_path *path = NULL; - struct ext4_ext_cache newex; struct ext4_extent *ex; + struct extent_status es; ext4_lblk_t next, next_del, start = 0, end = 0; ext4_lblk_t last = block + num; int exists, depth = 0, err = 0; @@ -2044,31 +2042,31 @@ static int ext4_fill_fiemap_extents(struct inode *inode, BUG_ON(end <= start); if (!exists) { - newex.ec_block = start; - newex.ec_len = end - start; - newex.ec_start = 0; + es.es_lblk = start; + es.es_len = end - start; + es.es_pblk = 0; } else { - newex.ec_block = le32_to_cpu(ex->ee_block); - newex.ec_len = ext4_ext_get_actual_len(ex); - newex.ec_start = ext4_ext_pblock(ex); + es.es_lblk = le32_to_cpu(ex->ee_block); + es.es_len = ext4_ext_get_actual_len(ex); + es.es_pblk = ext4_ext_pblock(ex); if (ext4_ext_is_uninitialized(ex)) flags |= FIEMAP_EXTENT_UNWRITTEN; } /* - * Find delayed extent and update newex accordingly. We call - * it even in !exists case to find out whether newex is the + * Find delayed extent and update es accordingly. We call + * it even in !exists case to find out whether es is the * last existing extent or not. */ - next_del = ext4_find_delayed_extent(inode, &newex); + next_del = ext4_find_delayed_extent(inode, &es); if (!exists && next_del) { exists = 1; flags |= FIEMAP_EXTENT_DELALLOC; } up_read(&EXT4_I(inode)->i_data_sem); - if (unlikely(newex.ec_len == 0)) { - EXT4_ERROR_INODE(inode, "newex.ec_len == 0"); + if (unlikely(es.es_len == 0)) { + EXT4_ERROR_INODE(inode, "es.es_len == 0"); err = -EIO; break; } @@ -2099,9 +2097,9 @@ static int ext4_fill_fiemap_extents(struct inode *inode, if (exists) { err = fiemap_fill_next_extent(fieinfo, - (__u64)newex.ec_block << blksize_bits, - (__u64)newex.ec_start << blksize_bits, - (__u64)newex.ec_len << blksize_bits, + (__u64)es.es_lblk << blksize_bits, + (__u64)es.es_pblk << blksize_bits, + (__u64)es.es_len << blksize_bits, flags); if (err < 0) break; @@ -2111,7 +2109,7 @@ static int ext4_fill_fiemap_extents(struct inode *inode, } } - block = newex.ec_block + newex.ec_len; + block = es.es_lblk + es.es_len; } if (path) { @@ -2122,21 +2120,6 @@ static int ext4_fill_fiemap_extents(struct inode *inode, return err; } -static void -ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block, - __u32 len, ext4_fsblk_t start) -{ - struct ext4_ext_cache *cex; - BUG_ON(len == 0); - spin_lock(&EXT4_I(inode)->i_block_reservation_lock); - trace_ext4_ext_put_in_cache(inode, block, len, start); - cex = &EXT4_I(inode)->i_cached_extent; - cex->ec_block = block; - cex->ec_len = len; - cex->ec_start = start; - spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); -} - /* * ext4_ext_put_gap_in_cache: * calculate boundaries of the gap that the requested block fits into @@ -2153,9 +2136,10 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, ex = path[depth].p_ext; if (ex == NULL) { - /* there is no extent yet, so gap is [0;-] */ - lblock = 0; - len = EXT_MAX_BLOCKS; + /* + * there is no extent yet, so gap is [0;-] and we + * don't cache it + */ ext_debug("cache gap(whole file):"); } else if (block < le32_to_cpu(ex->ee_block)) { lblock = block; @@ -2189,52 +2173,6 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, } ext_debug(" -> %u:%lu\n", lblock, len); - ext4_ext_put_in_cache(inode, lblock, len, 0); -} - -/* - * ext4_ext_in_cache() - * Checks to see if the given block is in the cache. - * If it is, the cached extent is stored in the given - * cache extent pointer. - * - * @inode: The files inode - * @block: The block to look for in the cache - * @ex: Pointer where the cached extent will be stored - * if it contains block - * - * Return 0 if cache is invalid; 1 if the cache is valid - */ -static int -ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, - struct ext4_extent *ex) -{ - struct ext4_ext_cache *cex; - int ret = 0; - - /* - * We borrow i_block_reservation_lock to protect i_cached_extent - */ - spin_lock(&EXT4_I(inode)->i_block_reservation_lock); - cex = &EXT4_I(inode)->i_cached_extent; - - /* has cache valid data? */ - if (cex->ec_len == 0) - goto errout; - - if (in_range(block, cex->ec_block, cex->ec_len)) { - ex->ee_block = cpu_to_le32(cex->ec_block); - ext4_ext_store_pblock(ex, cex->ec_start); - ex->ee_len = cpu_to_le16(cex->ec_len); - ext_debug("%u cached by %u:%u:%llu\n", - block, - cex->ec_block, cex->ec_len, cex->ec_start); - ret = 1; - } -errout: - trace_ext4_ext_in_cache(inode, block, ret); - spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); - return ret; } /* @@ -2674,8 +2612,6 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, return PTR_ERR(handle); again: - ext4_ext_invalidate_cache(inode); - trace_ext4_ext_remove_space(inode, start, depth); /* @@ -3917,35 +3853,6 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, map->m_lblk, map->m_len, inode->i_ino); trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); - /* check in cache */ - if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) { - if (!newex.ee_start_lo && !newex.ee_start_hi) { - if ((sbi->s_cluster_ratio > 1) && - ext4_find_delalloc_cluster(inode, map->m_lblk)) - map->m_flags |= EXT4_MAP_FROM_CLUSTER; - - if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { - /* - * block isn't allocated yet and - * user doesn't want to allocate it - */ - goto out2; - } - /* we should allocate requested block */ - } else { - /* block is already allocated */ - if (sbi->s_cluster_ratio > 1) - map->m_flags |= EXT4_MAP_FROM_CLUSTER; - newblock = map->m_lblk - - le32_to_cpu(newex.ee_block) - + ext4_ext_pblock(&newex); - /* number of remaining blocks in the extent */ - allocated = ext4_ext_get_actual_len(&newex) - - (map->m_lblk - le32_to_cpu(newex.ee_block)); - goto out; - } - } - /* find extent for this block */ path = ext4_ext_find_extent(inode, map->m_lblk, NULL); if (IS_ERR(path)) { @@ -3992,15 +3899,9 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk, ee_block, ee_len, newblock); - /* - * Do not put uninitialized extent - * in the cache - */ - if (!ext4_ext_is_uninitialized(ex)) { - ext4_ext_put_in_cache(inode, ee_block, - ee_len, ee_start); + if (!ext4_ext_is_uninitialized(ex)) goto out; - } + allocated = ext4_ext_handle_uninitialized_extents( handle, inode, map, path, flags, allocated, newblock); @@ -4262,10 +4163,9 @@ got_allocated_blocks: * Cache the extent and update transaction to commit on fdatasync only * when it is _not_ an uninitialized extent. */ - if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) { - ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock); + if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) ext4_update_inode_fsync_trans(handle, inode, 1); - } else + else ext4_update_inode_fsync_trans(handle, inode, 0); out: if (allocated > map->m_len) @@ -4324,7 +4224,6 @@ void ext4_ext_truncate(struct inode *inode) goto out_stop; down_write(&EXT4_I(inode)->i_data_sem); - ext4_ext_invalidate_cache(inode); ext4_discard_preallocations(inode); @@ -4574,42 +4473,42 @@ int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, } /* - * If newex is not existing extent (newex->ec_start equals zero) find - * delayed extent at start of newex and update newex accordingly and + * If newes is not existing extent (newes->ec_pblk equals zero) find + * delayed extent at start of newes and update newes accordingly and * return start of the next delayed extent. * - * If newex is existing extent (newex->ec_start is not equal zero) + * If newes is existing extent (newes->ec_pblk is not equal zero) * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed - * extent found. Leave newex unmodified. + * extent found. Leave newes unmodified. */ static int ext4_find_delayed_extent(struct inode *inode, - struct ext4_ext_cache *newex) + struct extent_status *newes) { struct extent_status es; ext4_lblk_t block, next_del; - ext4_es_find_delayed_extent(inode, newex->ec_block, &es); + ext4_es_find_delayed_extent(inode, newes->es_lblk, &es); - if (newex->ec_start == 0) { + if (newes->es_pblk == 0) { /* - * No extent in extent-tree contains block @newex->ec_start, + * No extent in extent-tree contains block @newes->es_pblk, * then the block may stay in 1)a hole or 2)delayed-extent. */ if (es.es_len == 0) /* A hole found. */ return 0; - if (es.es_lblk > newex->ec_block) { + if (es.es_lblk > newes->es_lblk) { /* A hole found. */ - newex->ec_len = min(es.es_lblk - newex->ec_block, - newex->ec_len); + newes->es_len = min(es.es_lblk - newes->es_lblk, + newes->es_len); return 0; } - newex->ec_len = es.es_lblk + es.es_len - newex->ec_block; + newes->es_len = es.es_lblk + es.es_len - newes->es_lblk; } - block = newex->ec_block + newex->ec_len; + block = newes->es_lblk + newes->es_len; ext4_es_find_delayed_extent(inode, block, &es); if (es.es_len == 0) next_del = EXT_MAX_BLOCKS; @@ -4813,14 +4712,12 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) goto out; down_write(&EXT4_I(inode)->i_data_sem); - ext4_ext_invalidate_cache(inode); ext4_discard_preallocations(inode); err = ext4_es_remove_extent(inode, first_block, stop_block - first_block); err = ext4_ext_remove_space(inode, first_block, stop_block - 1); - ext4_ext_invalidate_cache(inode); ext4_discard_preallocations(inode); if (IS_SYNC(inode)) diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index d9cc5ee..b9222c8 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -761,9 +761,6 @@ out: kfree(donor_path); } - ext4_ext_invalidate_cache(orig_inode); - ext4_ext_invalidate_cache(donor_inode);