From 79a2f25784973e6f9e866de30f53741dfa1abcfd Mon Sep 17 00:00:00 2001 From: Alex Tomas Date: Mon, 28 Jan 2008 23:58:27 -0500 Subject: [PATCH] --- yaml --- r: 77909 b: refs/heads/master c: 1988b51e476bd097d910c9245b53f2e38aedaf0d h: refs/heads/master i: 77907: 0cd637cf887fc59f7fb600b40d15fcfbc0aa9eb4 v: v3 --- [refs] | 2 +- trunk/fs/ext4/extents.c | 142 ++++++++++++++++++++++++++ trunk/include/linux/ext4_fs_extents.h | 4 + 3 files changed, 147 insertions(+), 1 deletion(-) diff --git a/[refs] b/[refs] index b7cb0dcd239e..b84049e83bf3 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: aa02ad67d9b308290fde390682cd039b29f7ab85 +refs/heads/master: 1988b51e476bd097d910c9245b53f2e38aedaf0d diff --git a/trunk/fs/ext4/extents.c b/trunk/fs/ext4/extents.c index 01eda5c5281e..f5cf2a94b6fc 100644 --- a/trunk/fs/ext4/extents.c +++ b/trunk/fs/ext4/extents.c @@ -1016,6 +1016,148 @@ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, return err; } +/* + * search the closest allocated block to the left for *logical + * and returns it at @logical + it's physical address at @phys + * if *logical is the smallest allocated block, the function + * returns 0 at @phys + * return value contains 0 (success) or error code + */ +int +ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, + ext4_lblk_t *logical, ext4_fsblk_t *phys) +{ + struct ext4_extent_idx *ix; + struct ext4_extent *ex; + int depth; + + BUG_ON(path == NULL); + depth = path->p_depth; + *phys = 0; + + if (depth == 0 && path->p_ext == NULL) + return 0; + + /* usually extent in the path covers blocks smaller + * then *logical, but it can be that extent is the + * first one in the file */ + + ex = path[depth].p_ext; + if (*logical < le32_to_cpu(ex->ee_block)) { + BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex); + while (--depth >= 0) { + ix = path[depth].p_idx; + BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr)); + } + return 0; + } + + BUG_ON(*logical < le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)); + + *logical = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1; + *phys = ext_pblock(ex) + le16_to_cpu(ex->ee_len) - 1; + return 0; +} + +/* + * search the closest allocated block to the right for *logical + * and returns it at @logical + it's physical address at @phys + * if *logical is the smallest allocated block, the function + * returns 0 at @phys + * return value contains 0 (success) or error code + */ +int +ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, + ext4_lblk_t *logical, ext4_fsblk_t *phys) +{ + struct buffer_head *bh = NULL; + struct ext4_extent_header *eh; + struct ext4_extent_idx *ix; + struct ext4_extent *ex; + ext4_fsblk_t block; + int depth; + + BUG_ON(path == NULL); + depth = path->p_depth; + *phys = 0; + + if (depth == 0 && path->p_ext == NULL) + return 0; + + /* usually extent in the path covers blocks smaller + * then *logical, but it can be that extent is the + * first one in the file */ + + ex = path[depth].p_ext; + if (*logical < le32_to_cpu(ex->ee_block)) { + BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex); + while (--depth >= 0) { + ix = path[depth].p_idx; + BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr)); + } + *logical = le32_to_cpu(ex->ee_block); + *phys = ext_pblock(ex); + return 0; + } + + BUG_ON(*logical < le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)); + + if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { + /* next allocated block in this leaf */ + ex++; + *logical = le32_to_cpu(ex->ee_block); + *phys = ext_pblock(ex); + return 0; + } + + /* go up and search for index to the right */ + while (--depth >= 0) { + ix = path[depth].p_idx; + if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) + break; + } + + if (depth < 0) { + /* we've gone up to the root and + * found no index to the right */ + return 0; + } + + /* we've found index to the right, let's + * follow it and find the closest allocated + * block to the right */ + ix++; + block = idx_pblock(ix); + while (++depth < path->p_depth) { + bh = sb_bread(inode->i_sb, block); + if (bh == NULL) + return -EIO; + eh = ext_block_hdr(bh); + if (ext4_ext_check_header(inode, eh, depth)) { + put_bh(bh); + return -EIO; + } + ix = EXT_FIRST_INDEX(eh); + block = idx_pblock(ix); + put_bh(bh); + } + + bh = sb_bread(inode->i_sb, block); + if (bh == NULL) + return -EIO; + eh = ext_block_hdr(bh); + if (ext4_ext_check_header(inode, eh, path->p_depth - depth)) { + put_bh(bh); + return -EIO; + } + ex = EXT_FIRST_EXTENT(eh); + *logical = le32_to_cpu(ex->ee_block); + *phys = ext_pblock(ex); + put_bh(bh); + return 0; + +} + /* * ext4_ext_next_allocated_block: * returns allocated block in subsequent extent or EXT_MAX_BLOCK. diff --git a/trunk/include/linux/ext4_fs_extents.h b/trunk/include/linux/ext4_fs_extents.h index 1cfb4854c964..697da4bce6c5 100644 --- a/trunk/include/linux/ext4_fs_extents.h +++ b/trunk/include/linux/ext4_fs_extents.h @@ -223,5 +223,9 @@ extern unsigned int ext4_ext_check_overlap(struct inode *, struct ext4_extent *, extern int ext4_ext_insert_extent(handle_t *, struct inode *, struct ext4_ext_path *, struct ext4_extent *); extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t, struct ext4_ext_path *); +extern int ext4_ext_search_left(struct inode *, struct ext4_ext_path *, + ext4_lblk_t *, ext4_fsblk_t *); +extern int ext4_ext_search_right(struct inode *, struct ext4_ext_path *, + ext4_lblk_t *, ext4_fsblk_t *); #endif /* _LINUX_EXT4_EXTENTS */