| /* |
| * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com |
| * Written by Alex Tomas <alex@clusterfs.com> |
| * |
| * Architecture independence: |
| * Copyright (c) 2005, Bull S.A. |
| * Written by Pierre Peiffer <pierre.peiffer@bull.net> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public Licens |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- |
| */ |
| |
| /* |
| * Extents support for EXT4 |
| * |
| * TODO: |
| * - ext4*_error() should be used in some situations |
| * - analyze all BUG()/BUG_ON(), use -EIO where appropriate |
| * - smart tree reduction |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/time.h> |
| #include <linux/ext4_jbd2.h> |
| #include <linux/jbd2.h> |
| #include <linux/highuid.h> |
| #include <linux/pagemap.h> |
| #include <linux/quotaops.h> |
| #include <linux/string.h> |
| #include <linux/slab.h> |
| #include <linux/falloc.h> |
| #include <linux/ext4_fs_extents.h> |
| #include <asm/uaccess.h> |
| |
| |
| /* |
| * ext_pblock: |
| * combine low and high parts of physical block number into ext4_fsblk_t |
| */ |
| static ext4_fsblk_t ext_pblock(struct ext4_extent *ex) |
| { |
| ext4_fsblk_t block; |
| |
| block = le32_to_cpu(ex->ee_start_lo); |
| block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1; |
| return block; |
| } |
| |
| /* |
| * idx_pblock: |
| * combine low and high parts of a leaf physical block number into ext4_fsblk_t |
| */ |
| ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix) |
| { |
| ext4_fsblk_t block; |
| |
| block = le32_to_cpu(ix->ei_leaf_lo); |
| block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1; |
| return block; |
| } |
| |
| /* |
| * ext4_ext_store_pblock: |
| * stores a large physical block number into an extent struct, |
| * breaking it into parts |
| */ |
| void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb) |
| { |
| ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff)); |
| ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); |
| } |
| |
| /* |
| * ext4_idx_store_pblock: |
| * stores a large physical block number into an index struct, |
| * breaking it into parts |
| */ |
| static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb) |
| { |
| ix->ei_leaf_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff)); |
| ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); |
| } |
| |
| static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed) |
| { |
| int err; |
| |
| if (handle->h_buffer_credits > needed) |
| return handle; |
| if (!ext4_journal_extend(handle, needed)) |
| return handle; |
| err = ext4_journal_restart(handle, needed); |
| |
| return handle; |
| } |
| |
| /* |
| * could return: |
| * - EROFS |
| * - ENOMEM |
| */ |
| static int ext4_ext_get_access(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| if (path->p_bh) { |
| /* path points to block */ |
| return ext4_journal_get_write_access(handle, path->p_bh); |
| } |
| /* path points to leaf/index in inode body */ |
| /* we use in-core data, no need to protect them */ |
| return 0; |
| } |
| |
| /* |
| * could return: |
| * - EROFS |
| * - ENOMEM |
| * - EIO |
| */ |
| static int ext4_ext_dirty(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| int err; |
| if (path->p_bh) { |
| /* path points to block */ |
| err = ext4_journal_dirty_metadata(handle, path->p_bh); |
| } else { |
| /* path points to leaf/index in inode body */ |
| err = ext4_mark_inode_dirty(handle, inode); |
| } |
| return err; |
| } |
| |
| static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, |
| struct ext4_ext_path *path, |
| ext4_lblk_t block) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| ext4_fsblk_t bg_start; |
| ext4_fsblk_t last_block; |
| ext4_grpblk_t colour; |
| int depth; |
| |
| if (path) { |
| struct ext4_extent *ex; |
| depth = path->p_depth; |
| |
| /* try to predict block placement */ |
| ex = path[depth].p_ext; |
| if (ex) |
| return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); |
| |
| /* it looks like index is empty; |
| * try to find starting block from index itself */ |
| if (path[depth].p_bh) |
| return path[depth].p_bh->b_blocknr; |
| } |
| |
| /* OK. use inode's group */ |
| bg_start = (ei->i_block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) + |
| le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block); |
| last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1; |
| |
| if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block) |
| colour = (current->pid % 16) * |
| (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); |
| else |
| colour = (current->pid % 16) * ((last_block - bg_start) / 16); |
| return bg_start + colour + block; |
| } |
| |
| static ext4_fsblk_t |
| ext4_ext_new_block(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *ex, int *err) |
| { |
| ext4_fsblk_t goal, newblock; |
| |
| goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); |
| newblock = ext4_new_block(handle, inode, goal, err); |
| return newblock; |
| } |
| |
| static int ext4_ext_space_block(struct inode *inode) |
| { |
| int size; |
| |
| size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| / sizeof(struct ext4_extent); |
| #ifdef AGGRESSIVE_TEST |
| if (size > 6) |
| size = 6; |
| #endif |
| return size; |
| } |
| |
| static int ext4_ext_space_block_idx(struct inode *inode) |
| { |
| int size; |
| |
| size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| / sizeof(struct ext4_extent_idx); |
| #ifdef AGGRESSIVE_TEST |
| if (size > 5) |
| size = 5; |
| #endif |
| return size; |
| } |
| |
| static int ext4_ext_space_root(struct inode *inode) |
| { |
| int size; |
| |
| size = sizeof(EXT4_I(inode)->i_data); |
| size -= sizeof(struct ext4_extent_header); |
| size /= sizeof(struct ext4_extent); |
| #ifdef AGGRESSIVE_TEST |
| if (size > 3) |
| size = 3; |
| #endif |
| return size; |
| } |
| |
| static int ext4_ext_space_root_idx(struct inode *inode) |
| { |
| int size; |
| |
| size = sizeof(EXT4_I(inode)->i_data); |
| size -= sizeof(struct ext4_extent_header); |
| size /= sizeof(struct ext4_extent_idx); |
| #ifdef AGGRESSIVE_TEST |
| if (size > 4) |
| size = 4; |
| #endif |
| return size; |
| } |
| |
| static int |
| ext4_ext_max_entries(struct inode *inode, int depth) |
| { |
| int max; |
| |
| if (depth == ext_depth(inode)) { |
| if (depth == 0) |
| max = ext4_ext_space_root(inode); |
| else |
| max = ext4_ext_space_root_idx(inode); |
| } else { |
| if (depth == 0) |
| max = ext4_ext_space_block(inode); |
| else |
| max = ext4_ext_space_block_idx(inode); |
| } |
| |
| return max; |
| } |
| |
| static int __ext4_ext_check_header(const char *function, struct inode *inode, |
| struct ext4_extent_header *eh, |
| int depth) |
| { |
| const char *error_msg; |
| int max = 0; |
| |
| if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { |
| error_msg = "invalid magic"; |
| goto corrupted; |
| } |
| if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { |
| error_msg = "unexpected eh_depth"; |
| goto corrupted; |
| } |
| if (unlikely(eh->eh_max == 0)) { |
| error_msg = "invalid eh_max"; |
| goto corrupted; |
| } |
| max = ext4_ext_max_entries(inode, depth); |
| if (unlikely(le16_to_cpu(eh->eh_max) > max)) { |
| error_msg = "too large eh_max"; |
| goto corrupted; |
| } |
| if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { |
| error_msg = "invalid eh_entries"; |
| goto corrupted; |
| } |
| return 0; |
| |
| corrupted: |
| ext4_error(inode->i_sb, function, |
| "bad header in inode #%lu: %s - magic %x, " |
| "entries %u, max %u(%u), depth %u(%u)", |
| inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic), |
| le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), |
| max, le16_to_cpu(eh->eh_depth), depth); |
| |
| return -EIO; |
| } |
| |
| #define ext4_ext_check_header(inode, eh, depth) \ |
| __ext4_ext_check_header(__func__, inode, eh, depth) |
| |
| #ifdef EXT_DEBUG |
| static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) |
| { |
| int k, l = path->p_depth; |
| |
| ext_debug("path:"); |
| for (k = 0; k <= l; k++, path++) { |
| if (path->p_idx) { |
| ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), |
| idx_pblock(path->p_idx)); |
| } else if (path->p_ext) { |
| ext_debug(" %d:%d:%llu ", |
| le32_to_cpu(path->p_ext->ee_block), |
| ext4_ext_get_actual_len(path->p_ext), |
| ext_pblock(path->p_ext)); |
| } else |
| ext_debug(" []"); |
| } |
| ext_debug("\n"); |
| } |
| |
| static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) |
| { |
| int depth = ext_depth(inode); |
| struct ext4_extent_header *eh; |
| struct ext4_extent *ex; |
| int i; |
| |
| if (!path) |
| return; |
| |
| eh = path[depth].p_hdr; |
| ex = EXT_FIRST_EXTENT(eh); |
| |
| for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { |
| ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block), |
| ext4_ext_get_actual_len(ex), ext_pblock(ex)); |
| } |
| ext_debug("\n"); |
| } |
| #else |
| #define ext4_ext_show_path(inode,path) |
| #define ext4_ext_show_leaf(inode,path) |
| #endif |
| |
| void ext4_ext_drop_refs(struct ext4_ext_path *path) |
| { |
| int depth = path->p_depth; |
| int i; |
| |
| for (i = 0; i <= depth; i++, path++) |
| if (path->p_bh) { |
| brelse(path->p_bh); |
| path->p_bh = NULL; |
| } |
| } |
| |
| /* |
| * ext4_ext_binsearch_idx: |
| * binary search for the closest index of the given block |
| * the header must be checked before calling this |
| */ |
| static void |
| ext4_ext_binsearch_idx(struct inode *inode, |
| struct ext4_ext_path *path, ext4_lblk_t block) |
| { |
| struct ext4_extent_header *eh = path->p_hdr; |
| struct ext4_extent_idx *r, *l, *m; |
| |
| |
| ext_debug("binsearch for %u(idx): ", block); |
| |
| l = EXT_FIRST_INDEX(eh) + 1; |
| r = EXT_LAST_INDEX(eh); |
| while (l <= r) { |
| m = l + (r - l) / 2; |
| if (block < le32_to_cpu(m->ei_block)) |
| r = m - 1; |
| else |
| l = m + 1; |
| ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), |
| m, le32_to_cpu(m->ei_block), |
| r, le32_to_cpu(r->ei_block)); |
| } |
| |
| path->p_idx = l - 1; |
| ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), |
| idx_pblock(path->p_idx)); |
| |
| #ifdef CHECK_BINSEARCH |
| { |
| struct ext4_extent_idx *chix, *ix; |
| int k; |
| |
| chix = ix = EXT_FIRST_INDEX(eh); |
| for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { |
| if (k != 0 && |
| le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { |
| printk("k=%d, ix=0x%p, first=0x%p\n", k, |
| ix, EXT_FIRST_INDEX(eh)); |
| printk("%u <= %u\n", |
| le32_to_cpu(ix->ei_block), |
| le32_to_cpu(ix[-1].ei_block)); |
| } |
| BUG_ON(k && le32_to_cpu(ix->ei_block) |
| <= le32_to_cpu(ix[-1].ei_block)); |
| if (block < le32_to_cpu(ix->ei_block)) |
| break; |
| chix = ix; |
| } |
| BUG_ON(chix != path->p_idx); |
| } |
| #endif |
| |
| } |
| |
| /* |
| * ext4_ext_binsearch: |
| * binary search for closest extent of the given block |
| * the header must be checked before calling this |
| */ |
| static void |
| ext4_ext_binsearch(struct inode *inode, |
| struct ext4_ext_path *path, ext4_lblk_t block) |
| { |
| struct ext4_extent_header *eh = path->p_hdr; |
| struct ext4_extent *r, *l, *m; |
| |
| if (eh->eh_entries == 0) { |
| /* |
| * this leaf is empty: |
| * we get such a leaf in split/add case |
| */ |
| return; |
| } |
| |
| ext_debug("binsearch for %u: ", block); |
| |
| l = EXT_FIRST_EXTENT(eh) + 1; |
| r = EXT_LAST_EXTENT(eh); |
| |
| while (l <= r) { |
| m = l + (r - l) / 2; |
| if (block < le32_to_cpu(m->ee_block)) |
| r = m - 1; |
| else |
| l = m + 1; |
| ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), |
| m, le32_to_cpu(m->ee_block), |
| r, le32_to_cpu(r->ee_block)); |
| } |
| |
| path->p_ext = l - 1; |
| ext_debug(" -> %d:%llu:%d ", |
| le32_to_cpu(path->p_ext->ee_block), |
| ext_pblock(path->p_ext), |
| ext4_ext_get_actual_len(path->p_ext)); |
| |
| #ifdef CHECK_BINSEARCH |
| { |
| struct ext4_extent *chex, *ex; |
| int k; |
| |
| chex = ex = EXT_FIRST_EXTENT(eh); |
| for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { |
| BUG_ON(k && le32_to_cpu(ex->ee_block) |
| <= le32_to_cpu(ex[-1].ee_block)); |
| if (block < le32_to_cpu(ex->ee_block)) |
| break; |
| chex = ex; |
| } |
| BUG_ON(chex != path->p_ext); |
| } |
| #endif |
| |
| } |
| |
| int ext4_ext_tree_init(handle_t *handle, struct inode *inode) |
| { |
| struct ext4_extent_header *eh; |
| |
| eh = ext_inode_hdr(inode); |
| eh->eh_depth = 0; |
| eh->eh_entries = 0; |
| eh->eh_magic = EXT4_EXT_MAGIC; |
| eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode)); |
| ext4_mark_inode_dirty(handle, inode); |
| ext4_ext_invalidate_cache(inode); |
| return 0; |
| } |
| |
| struct ext4_ext_path * |
| ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, |
| struct ext4_ext_path *path) |
| { |
| struct ext4_extent_header *eh; |
| struct buffer_head *bh; |
| short int depth, i, ppos = 0, alloc = 0; |
| |
| eh = ext_inode_hdr(inode); |
| depth = ext_depth(inode); |
| if (ext4_ext_check_header(inode, eh, depth)) |
| return ERR_PTR(-EIO); |
| |
| |
| /* account possible depth increase */ |
| if (!path) { |
| path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), |
| GFP_NOFS); |
| if (!path) |
| return ERR_PTR(-ENOMEM); |
| alloc = 1; |
| } |
| path[0].p_hdr = eh; |
| |
| i = depth; |
| /* walk through the tree */ |
| while (i) { |
| ext_debug("depth %d: num %d, max %d\n", |
| ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); |
| |
| ext4_ext_binsearch_idx(inode, path + ppos, block); |
| path[ppos].p_block = idx_pblock(path[ppos].p_idx); |
| path[ppos].p_depth = i; |
| path[ppos].p_ext = NULL; |
| |
| bh = sb_bread(inode->i_sb, path[ppos].p_block); |
| if (!bh) |
| goto err; |
| |
| eh = ext_block_hdr(bh); |
| ppos++; |
| BUG_ON(ppos > depth); |
| path[ppos].p_bh = bh; |
| path[ppos].p_hdr = eh; |
| i--; |
| |
| if (ext4_ext_check_header(inode, eh, i)) |
| goto err; |
| } |
| |
| path[ppos].p_depth = i; |
| path[ppos].p_hdr = eh; |
| path[ppos].p_ext = NULL; |
| path[ppos].p_idx = NULL; |
| |
| /* find extent */ |
| ext4_ext_binsearch(inode, path + ppos, block); |
| |
| ext4_ext_show_path(inode, path); |
| |
| return path; |
| |
| err: |
| ext4_ext_drop_refs(path); |
| if (alloc) |
| kfree(path); |
| return ERR_PTR(-EIO); |
| } |
| |
| /* |
| * ext4_ext_insert_index: |
| * insert new index [@logical;@ptr] into the block at @curp; |
| * check where to insert: before @curp or after @curp |
| */ |
| static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *curp, |
| int logical, ext4_fsblk_t ptr) |
| { |
| struct ext4_extent_idx *ix; |
| int len, err; |
| |
| err = ext4_ext_get_access(handle, inode, curp); |
| if (err) |
| return err; |
| |
| BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block)); |
| len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx; |
| if (logical > le32_to_cpu(curp->p_idx->ei_block)) { |
| /* insert after */ |
| if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) { |
| len = (len - 1) * sizeof(struct ext4_extent_idx); |
| len = len < 0 ? 0 : len; |
| ext_debug("insert new index %d after: %llu. " |
| "move %d from 0x%p to 0x%p\n", |
| logical, ptr, len, |
| (curp->p_idx + 1), (curp->p_idx + 2)); |
| memmove(curp->p_idx + 2, curp->p_idx + 1, len); |
| } |
| ix = curp->p_idx + 1; |
| } else { |
| /* insert before */ |
| len = len * sizeof(struct ext4_extent_idx); |
| len = len < 0 ? 0 : len; |
| ext_debug("insert new index %d before: %llu. " |
| "move %d from 0x%p to 0x%p\n", |
| logical, ptr, len, |
| curp->p_idx, (curp->p_idx + 1)); |
| memmove(curp->p_idx + 1, curp->p_idx, len); |
| ix = curp->p_idx; |
| } |
| |
| ix->ei_block = cpu_to_le32(logical); |
| ext4_idx_store_pblock(ix, ptr); |
| le16_add_cpu(&curp->p_hdr->eh_entries, 1); |
| |
| BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries) |
| > le16_to_cpu(curp->p_hdr->eh_max)); |
| BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr)); |
| |
| err = ext4_ext_dirty(handle, inode, curp); |
| ext4_std_error(inode->i_sb, err); |
| |
| return err; |
| } |
| |
| /* |
| * ext4_ext_split: |
| * inserts new subtree into the path, using free index entry |
| * at depth @at: |
| * - allocates all needed blocks (new leaf and all intermediate index blocks) |
| * - makes decision where to split |
| * - moves remaining extents and index entries (right to the split point) |
| * into the newly allocated blocks |
| * - initializes subtree |
| */ |
| static int ext4_ext_split(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *newext, int at) |
| { |
| struct buffer_head *bh = NULL; |
| int depth = ext_depth(inode); |
| struct ext4_extent_header *neh; |
| struct ext4_extent_idx *fidx; |
| struct ext4_extent *ex; |
| int i = at, k, m, a; |
| ext4_fsblk_t newblock, oldblock; |
| __le32 border; |
| ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ |
| int err = 0; |
| |
| /* make decision: where to split? */ |
| /* FIXME: now decision is simplest: at current extent */ |
| |
| /* if current leaf will be split, then we should use |
| * border from split point */ |
| BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr)); |
| if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { |
| border = path[depth].p_ext[1].ee_block; |
| ext_debug("leaf will be split." |
| " next leaf starts at %d\n", |
| le32_to_cpu(border)); |
| } else { |
| border = newext->ee_block; |
| ext_debug("leaf will be added." |
| " next leaf starts at %d\n", |
| le32_to_cpu(border)); |
| } |
| |
| /* |
| * If error occurs, then we break processing |
| * and mark filesystem read-only. index won't |
| * be inserted and tree will be in consistent |
| * state. Next mount will repair buffers too. |
| */ |
| |
| /* |
| * Get array to track all allocated blocks. |
| * We need this to handle errors and free blocks |
| * upon them. |
| */ |
| ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); |
| if (!ablocks) |
| return -ENOMEM; |
| |
| /* allocate all needed blocks */ |
| ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); |
| for (a = 0; a < depth - at; a++) { |
| newblock = ext4_ext_new_block(handle, inode, path, newext, &err); |
| if (newblock == 0) |
| goto cleanup; |
| ablocks[a] = newblock; |
| } |
| |
| /* initialize new leaf */ |
| newblock = ablocks[--a]; |
| BUG_ON(newblock == 0); |
| bh = sb_getblk(inode->i_sb, newblock); |
| if (!bh) { |
| err = -EIO; |
| goto cleanup; |
| } |
| lock_buffer(bh); |
| |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) |
| goto cleanup; |
| |
| neh = ext_block_hdr(bh); |
| neh->eh_entries = 0; |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); |
| neh->eh_magic = EXT4_EXT_MAGIC; |
| neh->eh_depth = 0; |
| ex = EXT_FIRST_EXTENT(neh); |
| |
| /* move remainder of path[depth] to the new leaf */ |
| BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max); |
| /* start copy from next extent */ |
| /* TODO: we could do it by single memmove */ |
| m = 0; |
| path[depth].p_ext++; |
| while (path[depth].p_ext <= |
| EXT_MAX_EXTENT(path[depth].p_hdr)) { |
| ext_debug("move %d:%llu:%d in new leaf %llu\n", |
| le32_to_cpu(path[depth].p_ext->ee_block), |
| ext_pblock(path[depth].p_ext), |
| ext4_ext_get_actual_len(path[depth].p_ext), |
| newblock); |
| /*memmove(ex++, path[depth].p_ext++, |
| sizeof(struct ext4_extent)); |
| neh->eh_entries++;*/ |
| path[depth].p_ext++; |
| m++; |
| } |
| if (m) { |
| memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m); |
| le16_add_cpu(&neh->eh_entries, m); |
| } |
| |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| err = ext4_journal_dirty_metadata(handle, bh); |
| if (err) |
| goto cleanup; |
| brelse(bh); |
| bh = NULL; |
| |
| /* correct old leaf */ |
| if (m) { |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto cleanup; |
| le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| if (err) |
| goto cleanup; |
| |
| } |
| |
| /* create intermediate indexes */ |
| k = depth - at - 1; |
| BUG_ON(k < 0); |
| if (k) |
| ext_debug("create %d intermediate indices\n", k); |
| /* insert new index into current index block */ |
| /* current depth stored in i var */ |
| i = depth - 1; |
| while (k--) { |
| oldblock = newblock; |
| newblock = ablocks[--a]; |
| bh = sb_getblk(inode->i_sb, newblock); |
| if (!bh) { |
| err = -EIO; |
| goto cleanup; |
| } |
| lock_buffer(bh); |
| |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) |
| goto cleanup; |
| |
| neh = ext_block_hdr(bh); |
| neh->eh_entries = cpu_to_le16(1); |
| neh->eh_magic = EXT4_EXT_MAGIC; |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); |
| neh->eh_depth = cpu_to_le16(depth - i); |
| fidx = EXT_FIRST_INDEX(neh); |
| fidx->ei_block = border; |
| ext4_idx_store_pblock(fidx, oldblock); |
| |
| ext_debug("int.index at %d (block %llu): %u -> %llu\n", |
| i, newblock, le32_to_cpu(border), oldblock); |
| /* copy indexes */ |
| m = 0; |
| path[i].p_idx++; |
| |
| ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, |
| EXT_MAX_INDEX(path[i].p_hdr)); |
| BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) != |
| EXT_LAST_INDEX(path[i].p_hdr)); |
| while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) { |
| ext_debug("%d: move %d:%llu in new index %llu\n", i, |
| le32_to_cpu(path[i].p_idx->ei_block), |
| idx_pblock(path[i].p_idx), |
| newblock); |
| /*memmove(++fidx, path[i].p_idx++, |
| sizeof(struct ext4_extent_idx)); |
| neh->eh_entries++; |
| BUG_ON(neh->eh_entries > neh->eh_max);*/ |
| path[i].p_idx++; |
| m++; |
| } |
| if (m) { |
| memmove(++fidx, path[i].p_idx - m, |
| sizeof(struct ext4_extent_idx) * m); |
| le16_add_cpu(&neh->eh_entries, m); |
| } |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| err = ext4_journal_dirty_metadata(handle, bh); |
| if (err) |
| goto cleanup; |
| brelse(bh); |
| bh = NULL; |
| |
| /* correct old index */ |
| if (m) { |
| err = ext4_ext_get_access(handle, inode, path + i); |
| if (err) |
| goto cleanup; |
| le16_add_cpu(&path[i].p_hdr->eh_entries, -m); |
| err = ext4_ext_dirty(handle, inode, path + i); |
| if (err) |
| goto cleanup; |
| } |
| |
| i--; |
| } |
| |
| /* insert new index */ |
| err = ext4_ext_insert_index(handle, inode, path + at, |
| le32_to_cpu(border), newblock); |
| |
| cleanup: |
| if (bh) { |
| if (buffer_locked(bh)) |
| unlock_buffer(bh); |
| brelse(bh); |
| } |
| |
| if (err) { |
| /* free all allocated blocks in error case */ |
| for (i = 0; i < depth; i++) { |
| if (!ablocks[i]) |
| continue; |
| ext4_free_blocks(handle, inode, ablocks[i], 1, 1); |
| } |
| } |
| kfree(ablocks); |
| |
| return err; |
| } |
| |
| /* |
| * ext4_ext_grow_indepth: |
| * implements tree growing procedure: |
| * - allocates new block |
| * - moves top-level data (index block or leaf) into the new block |
| * - initializes new top-level, creating index that points to the |
| * just created block |
| */ |
| static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *newext) |
| { |
| struct ext4_ext_path *curp = path; |
| struct ext4_extent_header *neh; |
| struct ext4_extent_idx *fidx; |
| struct buffer_head *bh; |
| ext4_fsblk_t newblock; |
| int err = 0; |
| |
| newblock = ext4_ext_new_block(handle, inode, path, newext, &err); |
| if (newblock == 0) |
| return err; |
| |
| bh = sb_getblk(inode->i_sb, newblock); |
| if (!bh) { |
| err = -EIO; |
| ext4_std_error(inode->i_sb, err); |
| return err; |
| } |
| lock_buffer(bh); |
| |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) { |
| unlock_buffer(bh); |
| goto out; |
| } |
| |
| /* move top-level index/leaf into new block */ |
| memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); |
| |
| /* set size of new block */ |
| neh = ext_block_hdr(bh); |
| /* old root could have indexes or leaves |
| * so calculate e_max right way */ |
| if (ext_depth(inode)) |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); |
| else |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); |
| neh->eh_magic = EXT4_EXT_MAGIC; |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| err = ext4_journal_dirty_metadata(handle, bh); |
| if (err) |
| goto out; |
| |
| /* create index in new top-level index: num,max,pointer */ |
| err = ext4_ext_get_access(handle, inode, curp); |
| if (err) |
| goto out; |
| |
| curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; |
| curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode)); |
| curp->p_hdr->eh_entries = cpu_to_le16(1); |
| curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); |
| |
| if (path[0].p_hdr->eh_depth) |
| curp->p_idx->ei_block = |
| EXT_FIRST_INDEX(path[0].p_hdr)->ei_block; |
| else |
| curp->p_idx->ei_block = |
| EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; |
| ext4_idx_store_pblock(curp->p_idx, newblock); |
| |
| neh = ext_inode_hdr(inode); |
| fidx = EXT_FIRST_INDEX(neh); |
| ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", |
| le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), |
| le32_to_cpu(fidx->ei_block), idx_pblock(fidx)); |
| |
| neh->eh_depth = cpu_to_le16(path->p_depth + 1); |
| err = ext4_ext_dirty(handle, inode, curp); |
| out: |
| brelse(bh); |
| |
| return err; |
| } |
| |
| /* |
| * ext4_ext_create_new_leaf: |
| * finds empty index and adds new leaf. |
| * if no free index is found, then it requests in-depth growing. |
| */ |
| static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *newext) |
| { |
| struct ext4_ext_path *curp; |
| int depth, i, err = 0; |
| |
| repeat: |
| i = depth = ext_depth(inode); |
| |
| /* walk up to the tree and look for free index entry */ |
| curp = path + depth; |
| while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { |
| i--; |
| curp--; |
| } |
| |
| /* we use already allocated block for index block, |
| * so subsequent data blocks should be contiguous */ |
| if (EXT_HAS_FREE_INDEX(curp)) { |
| /* if we found index with free entry, then use that |
| * entry: create all needed subtree and add new leaf */ |
| err = ext4_ext_split(handle, inode, path, newext, i); |
| |
| /* refill path */ |
| ext4_ext_drop_refs(path); |
| path = ext4_ext_find_extent(inode, |
| (ext4_lblk_t)le32_to_cpu(newext->ee_block), |
| path); |
| if (IS_ERR(path)) |
| err = PTR_ERR(path); |
| } else { |
| /* tree is full, time to grow in depth */ |
| err = ext4_ext_grow_indepth(handle, inode, path, newext); |
| if (err) |
| goto out; |
| |
| /* refill path */ |
| ext4_ext_drop_refs(path); |
| path = ext4_ext_find_extent(inode, |
| (ext4_lblk_t)le32_to_cpu(newext->ee_block), |
| path); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| goto out; |
| } |
| |
| /* |
| * only first (depth 0 -> 1) produces free space; |
| * in all other cases we have to split the grown tree |
| */ |
| depth = ext_depth(inode); |
| if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { |
| /* now we need to split */ |
| goto repeat; |
| } |
| } |
| |
| out: |
| 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, ee_len; |
| |
| 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; |
| ee_len = ext4_ext_get_actual_len(ex); |
| 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) + ee_len)); |
| |
| *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; |
| *phys = ext_pblock(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, ee_len; |
| |
| 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; |
| ee_len = ext4_ext_get_actual_len(ex); |
| 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) + 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. |
| * NOTE: it considers block number from index entry as |
| * allocated block. Thus, index entries have to be consistent |
| * with leaves. |
| */ |
| static ext4_lblk_t |
| ext4_ext_next_allocated_block(struct ext4_ext_path *path) |
| { |
| int depth; |
| |
| BUG_ON(path == NULL); |
| depth = path->p_depth; |
| |
| if (depth == 0 && path->p_ext == NULL) |
| return EXT_MAX_BLOCK; |
| |
| while (depth >= 0) { |
| if (depth == path->p_depth) { |
| /* leaf */ |
| if (path[depth].p_ext != |
| EXT_LAST_EXTENT(path[depth].p_hdr)) |
| return le32_to_cpu(path[depth].p_ext[1].ee_block); |
| } else { |
| /* index */ |
| if (path[depth].p_idx != |
| EXT_LAST_INDEX(path[depth].p_hdr)) |
| return le32_to_cpu(path[depth].p_idx[1].ei_block); |
| } |
| depth--; |
| } |
| |
| return EXT_MAX_BLOCK; |
| } |
| |
| /* |
| * ext4_ext_next_leaf_block: |
| * returns first allocated block from next leaf or EXT_MAX_BLOCK |
| */ |
| static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| int depth; |
| |
| BUG_ON(path == NULL); |
| depth = path->p_depth; |
| |
| /* zero-tree has no leaf blocks at all */ |
| if (depth == 0) |
| return EXT_MAX_BLOCK; |
| |
| /* go to index block */ |
| depth--; |
| |
| while (depth >= 0) { |
| if (path[depth].p_idx != |
| EXT_LAST_INDEX(path[depth].p_hdr)) |
| return (ext4_lblk_t) |
| le32_to_cpu(path[depth].p_idx[1].ei_block); |
| depth--; |
| } |
| |
| return EXT_MAX_BLOCK; |
| } |
| |
| /* |
| * ext4_ext_correct_indexes: |
| * if leaf gets modified and modified extent is first in the leaf, |
| * then we have to correct all indexes above. |
| * TODO: do we need to correct tree in all cases? |
| */ |
| static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| struct ext4_extent_header *eh; |
| int depth = ext_depth(inode); |
| struct ext4_extent *ex; |
| __le32 border; |
| int k, err = 0; |
| |
| eh = path[depth].p_hdr; |
| ex = path[depth].p_ext; |
| BUG_ON(ex == NULL); |
| BUG_ON(eh == NULL); |
| |
| if (depth == 0) { |
| /* there is no tree at all */ |
| return 0; |
| } |
| |
| if (ex != EXT_FIRST_EXTENT(eh)) { |
| /* we correct tree if first leaf got modified only */ |
| return 0; |
| } |
| |
| /* |
| * TODO: we need correction if border is smaller than current one |
| */ |
| k = depth - 1; |
| border = path[depth].p_ext->ee_block; |
| err = ext4_ext_get_access(handle, inode, path + k); |
| if (err) |
| return err; |
| path[k].p_idx->ei_block = border; |
| err = ext4_ext_dirty(handle, inode, path + k); |
| if (err) |
| return err; |
| |
| while (k--) { |
| /* change all left-side indexes */ |
| if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) |
| break; |
| err = ext4_ext_get_access(handle, inode, path + k); |
| if (err) |
| break; |
| path[k].p_idx->ei_block = border; |
| err = ext4_ext_dirty(handle, inode, path + k); |
| if (err) |
| break; |
| } |
| |
| return err; |
| } |
| |
| static int |
| ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, |
| struct ext4_extent *ex2) |
| { |
| unsigned short ext1_ee_len, ext2_ee_len, max_len; |
| |
| /* |
| * Make sure that either both extents are uninitialized, or |
| * both are _not_. |
| */ |
| if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2)) |
| return 0; |
| |
| if (ext4_ext_is_uninitialized(ex1)) |
| max_len = EXT_UNINIT_MAX_LEN; |
| else |
| max_len = EXT_INIT_MAX_LEN; |
| |
| ext1_ee_len = ext4_ext_get_actual_len(ex1); |
| ext2_ee_len = ext4_ext_get_actual_len(ex2); |
| |
| if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != |
| le32_to_cpu(ex2->ee_block)) |
| return 0; |
| |
| /* |
| * To allow future support for preallocated extents to be added |
| * as an RO_COMPAT feature, refuse to merge to extents if |
| * this can result in the top bit of ee_len being set. |
| */ |
| if (ext1_ee_len + ext2_ee_len > max_len) |
| return 0; |
| #ifdef AGGRESSIVE_TEST |
| if (ext1_ee_len >= 4) |
| return 0; |
| #endif |
| |
| if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2)) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * This function tries to merge the "ex" extent to the next extent in the tree. |
| * It always tries to merge towards right. If you want to merge towards |
| * left, pass "ex - 1" as argument instead of "ex". |
| * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns |
| * 1 if they got merged. |
| */ |
| int ext4_ext_try_to_merge(struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *ex) |
| { |
| struct ext4_extent_header *eh; |
| unsigned int depth, len; |
| int merge_done = 0; |
| int uninitialized = 0; |
| |
| depth = ext_depth(inode); |
| BUG_ON(path[depth].p_hdr == NULL); |
| eh = path[depth].p_hdr; |
| |
| while (ex < EXT_LAST_EXTENT(eh)) { |
| if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) |
| break; |
| /* merge with next extent! */ |
| if (ext4_ext_is_uninitialized(ex)) |
| uninitialized = 1; |
| ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) |
| + ext4_ext_get_actual_len(ex + 1)); |
| if (uninitialized) |
| ext4_ext_mark_uninitialized(ex); |
| |
| if (ex + 1 < EXT_LAST_EXTENT(eh)) { |
| len = (EXT_LAST_EXTENT(eh) - ex - 1) |
| * sizeof(struct ext4_extent); |
| memmove(ex + 1, ex + 2, len); |
| } |
| le16_add_cpu(&eh->eh_entries, -1); |
| merge_done = 1; |
| WARN_ON(eh->eh_entries == 0); |
| if (!eh->eh_entries) |
| ext4_error(inode->i_sb, "ext4_ext_try_to_merge", |
| "inode#%lu, eh->eh_entries = 0!", inode->i_ino); |
| } |
| |
| return merge_done; |
| } |
| |
| /* |
| * check if a portion of the "newext" extent overlaps with an |
| * existing extent. |
| * |
| * If there is an overlap discovered, it updates the length of the newext |
| * such that there will be no overlap, and then returns 1. |
| * If there is no overlap found, it returns 0. |
| */ |
| unsigned int ext4_ext_check_overlap(struct inode *inode, |
| struct ext4_extent *newext, |
| struct ext4_ext_path *path) |
| { |
| ext4_lblk_t b1, b2; |
| unsigned int depth, len1; |
| unsigned int ret = 0; |
| |
| b1 = le32_to_cpu(newext->ee_block); |
| len1 = ext4_ext_get_actual_len(newext); |
| depth = ext_depth(inode); |
| if (!path[depth].p_ext) |
| goto out; |
| b2 = le32_to_cpu(path[depth].p_ext->ee_block); |
| |
| /* |
| * get the next allocated block if the extent in the path |
| * is before the requested block(s) |
| */ |
| if (b2 < b1) { |
| b2 = ext4_ext_next_allocated_block(path); |
| if (b2 == EXT_MAX_BLOCK) |
| goto out; |
| } |
| |
| /* check for wrap through zero on extent logical start block*/ |
| if (b1 + len1 < b1) { |
| len1 = EXT_MAX_BLOCK - b1; |
| newext->ee_len = cpu_to_le16(len1); |
| ret = 1; |
| } |
| |
| /* check for overlap */ |
| if (b1 + len1 > b2) { |
| newext->ee_len = cpu_to_le16(b2 - b1); |
| ret = 1; |
| } |
| out: |
| return ret; |
| } |
| |
| /* |
| * ext4_ext_insert_extent: |
| * tries to merge requsted extent into the existing extent or |
| * inserts requested extent as new one into the tree, |
| * creating new leaf in the no-space case. |
| */ |
| int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *newext) |
| { |
| struct ext4_extent_header * eh; |
| struct ext4_extent *ex, *fex; |
| struct ext4_extent *nearex; /* nearest extent */ |
| struct ext4_ext_path *npath = NULL; |
| int depth, len, err; |
| ext4_lblk_t next; |
| unsigned uninitialized = 0; |
| |
| BUG_ON(ext4_ext_get_actual_len(newext) == 0); |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| BUG_ON(path[depth].p_hdr == NULL); |
| |
| /* try to insert block into found extent and return */ |
| if (ex && ext4_can_extents_be_merged(inode, ex, newext)) { |
| ext_debug("append %d block to %d:%d (from %llu)\n", |
| ext4_ext_get_actual_len(newext), |
| le32_to_cpu(ex->ee_block), |
| ext4_ext_get_actual_len(ex), ext_pblock(ex)); |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| return err; |
| |
| /* |
| * ext4_can_extents_be_merged should have checked that either |
| * both extents are uninitialized, or both aren't. Thus we |
| * need to check only one of them here. |
| */ |
| if (ext4_ext_is_uninitialized(ex)) |
| uninitialized = 1; |
| ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) |
| + ext4_ext_get_actual_len(newext)); |
| if (uninitialized) |
| ext4_ext_mark_uninitialized(ex); |
| eh = path[depth].p_hdr; |
| nearex = ex; |
| goto merge; |
| } |
| |
| repeat: |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) |
| goto has_space; |
| |
| /* probably next leaf has space for us? */ |
| fex = EXT_LAST_EXTENT(eh); |
| next = ext4_ext_next_leaf_block(inode, path); |
| if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block) |
| && next != EXT_MAX_BLOCK) { |
| ext_debug("next leaf block - %d\n", next); |
| BUG_ON(npath != NULL); |
| npath = ext4_ext_find_extent(inode, next, NULL); |
| if (IS_ERR(npath)) |
| return PTR_ERR(npath); |
| BUG_ON(npath->p_depth != path->p_depth); |
| eh = npath[depth].p_hdr; |
| if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { |
| ext_debug("next leaf isnt full(%d)\n", |
| le16_to_cpu(eh->eh_entries)); |
| path = npath; |
| goto repeat; |
| } |
| ext_debug("next leaf has no free space(%d,%d)\n", |
| le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); |
| } |
| |
| /* |
| * There is no free space in the found leaf. |
| * We're gonna add a new leaf in the tree. |
| */ |
| err = ext4_ext_create_new_leaf(handle, inode, path, newext); |
| if (err) |
| goto cleanup; |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| |
| has_space: |
| nearex = path[depth].p_ext; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto cleanup; |
| |
| if (!nearex) { |
| /* there is no extent in this leaf, create first one */ |
| ext_debug("first extent in the leaf: %d:%llu:%d\n", |
| le32_to_cpu(newext->ee_block), |
| ext_pblock(newext), |
| ext4_ext_get_actual_len(newext)); |
| path[depth].p_ext = EXT_FIRST_EXTENT(eh); |
| } else if (le32_to_cpu(newext->ee_block) |
| > le32_to_cpu(nearex->ee_block)) { |
| /* BUG_ON(newext->ee_block == nearex->ee_block); */ |
| if (nearex != EXT_LAST_EXTENT(eh)) { |
| len = EXT_MAX_EXTENT(eh) - nearex; |
| len = (len - 1) * sizeof(struct ext4_extent); |
| len = len < 0 ? 0 : len; |
| ext_debug("insert %d:%llu:%d after: nearest 0x%p, " |
| "move %d from 0x%p to 0x%p\n", |
| le32_to_cpu(newext->ee_block), |
| ext_pblock(newext), |
| ext4_ext_get_actual_len(newext), |
| nearex, len, nearex + 1, nearex + 2); |
| memmove(nearex + 2, nearex + 1, len); |
| } |
| path[depth].p_ext = nearex + 1; |
| } else { |
| BUG_ON(newext->ee_block == nearex->ee_block); |
| len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent); |
| len = len < 0 ? 0 : len; |
| ext_debug("insert %d:%llu:%d before: nearest 0x%p, " |
| "move %d from 0x%p to 0x%p\n", |
| le32_to_cpu(newext->ee_block), |
| ext_pblock(newext), |
| ext4_ext_get_actual_len(newext), |
| nearex, len, nearex + 1, nearex + 2); |
| memmove(nearex + 1, nearex, len); |
| path[depth].p_ext = nearex; |
| } |
| |
| le16_add_cpu(&eh->eh_entries, 1); |
| nearex = path[depth].p_ext; |
| nearex->ee_block = newext->ee_block; |
| ext4_ext_store_pblock(nearex, ext_pblock(newext)); |
| nearex->ee_len = newext->ee_len; |
| |
| merge: |
| /* try to merge extents to the right */ |
| ext4_ext_try_to_merge(inode, path, nearex); |
| |
| /* try to merge extents to the left */ |
| |
| /* time to correct all indexes above */ |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| if (err) |
| goto cleanup; |
| |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| |
| cleanup: |
| if (npath) { |
| ext4_ext_drop_refs(npath); |
| kfree(npath); |
| } |
| ext4_ext_tree_changed(inode); |
| ext4_ext_invalidate_cache(inode); |
| return err; |
| } |
| |
| static void |
| ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block, |
| __u32 len, ext4_fsblk_t start, int type) |
| { |
| struct ext4_ext_cache *cex; |
| BUG_ON(len == 0); |
| cex = &EXT4_I(inode)->i_cached_extent; |
| cex->ec_type = type; |
| cex->ec_block = block; |
| cex->ec_len = len; |
| cex->ec_start = start; |
| } |
| |
| /* |
| * ext4_ext_put_gap_in_cache: |
| * calculate boundaries of the gap that the requested block fits into |
| * and cache this gap |
| */ |
| static void |
| ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, |
| ext4_lblk_t block) |
| { |
| int depth = ext_depth(inode); |
| unsigned long len; |
| ext4_lblk_t lblock; |
| struct ext4_extent *ex; |
| |
| ex = path[depth].p_ext; |
| if (ex == NULL) { |
| /* there is no extent yet, so gap is [0;-] */ |
| lblock = 0; |
| len = EXT_MAX_BLOCK; |
| ext_debug("cache gap(whole file):"); |
| } else if (block < le32_to_cpu(ex->ee_block)) { |
| lblock = block; |
| len = le32_to_cpu(ex->ee_block) - block; |
| ext_debug("cache gap(before): %u [%u:%u]", |
| block, |
| le32_to_cpu(ex->ee_block), |
| ext4_ext_get_actual_len(ex)); |
| } else if (block >= le32_to_cpu(ex->ee_block) |
| + ext4_ext_get_actual_len(ex)) { |
| ext4_lblk_t next; |
| lblock = le32_to_cpu(ex->ee_block) |
| + ext4_ext_get_actual_len(ex); |
| |
| next = ext4_ext_next_allocated_block(path); |
| ext_debug("cache gap(after): [%u:%u] %u", |
| le32_to_cpu(ex->ee_block), |
| ext4_ext_get_actual_len(ex), |
| block); |
| BUG_ON(next == lblock); |
| len = next - lblock; |
| } else { |
| lblock = len = 0; |
| BUG(); |
| } |
| |
| ext_debug(" -> %u:%lu\n", lblock, len); |
| ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP); |
| } |
| |
| static int |
| ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, |
| struct ext4_extent *ex) |
| { |
| struct ext4_ext_cache *cex; |
| |
| cex = &EXT4_I(inode)->i_cached_extent; |
| |
| /* has cache valid data? */ |
| if (cex->ec_type == EXT4_EXT_CACHE_NO) |
| return EXT4_EXT_CACHE_NO; |
| |
| BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP && |
| cex->ec_type != EXT4_EXT_CACHE_EXTENT); |
| if (block >= cex->ec_block && 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); |
| return cex->ec_type; |
| } |
| |
| /* not in cache */ |
| return EXT4_EXT_CACHE_NO; |
| } |
| |
| /* |
| * ext4_ext_rm_idx: |
| * removes index from the index block. |
| * It's used in truncate case only, thus all requests are for |
| * last index in the block only. |
| */ |
| static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| struct buffer_head *bh; |
| int err; |
| ext4_fsblk_t leaf; |
| |
| /* free index block */ |
| path--; |
| leaf = idx_pblock(path->p_idx); |
| BUG_ON(path->p_hdr->eh_entries == 0); |
| err = ext4_ext_get_access(handle, inode, path); |
| if (err) |
| return err; |
| le16_add_cpu(&path->p_hdr->eh_entries, -1); |
| err = ext4_ext_dirty(handle, inode, path); |
| if (err) |
| return err; |
| ext_debug("index is empty, remove it, free block %llu\n", leaf); |
| bh = sb_find_get_block(inode->i_sb, leaf); |
| ext4_forget(handle, 1, inode, bh, leaf); |
| ext4_free_blocks(handle, inode, leaf, 1, 1); |
| return err; |
| } |
| |
| /* |
| * ext4_ext_calc_credits_for_insert: |
| * This routine returns max. credits that the extent tree can consume. |
| * It should be OK for low-performance paths like ->writepage() |
| * To allow many writing processes to fit into a single transaction, |
| * the caller should calculate credits under i_data_sem and |
| * pass the actual path. |
| */ |
| int ext4_ext_calc_credits_for_insert(struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| int depth, needed; |
| |
| if (path) { |
| /* probably there is space in leaf? */ |
| depth = ext_depth(inode); |
| if (le16_to_cpu(path[depth].p_hdr->eh_entries) |
| < le16_to_cpu(path[depth].p_hdr->eh_max)) |
| return 1; |
| } |
| |
| /* |
| * given 32-bit logical block (4294967296 blocks), max. tree |
| * can be 4 levels in depth -- 4 * 340^4 == 53453440000. |
| * Let's also add one more level for imbalance. |
| */ |
| depth = 5; |
| |
| /* allocation of new data block(s) */ |
| needed = 2; |
| |
| /* |
| * tree can be full, so it would need to grow in depth: |
| * we need one credit to modify old root, credits for |
| * new root will be added in split accounting |
| */ |
| needed += 1; |
| |
| /* |
| * Index split can happen, we would need: |
| * allocate intermediate indexes (bitmap + group) |
| * + change two blocks at each level, but root (already included) |
| */ |
| needed += (depth * 2) + (depth * 2); |
| |
| /* any allocation modifies superblock */ |
| needed += 1; |
| |
| return needed; |
| } |
| |
| static int ext4_remove_blocks(handle_t *handle, struct inode *inode, |
| struct ext4_extent *ex, |
| ext4_lblk_t from, ext4_lblk_t to) |
| { |
| struct buffer_head *bh; |
| unsigned short ee_len = ext4_ext_get_actual_len(ex); |
| int i, metadata = 0; |
| |
| if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) |
| metadata = 1; |
| #ifdef EXTENTS_STATS |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| spin_lock(&sbi->s_ext_stats_lock); |
| sbi->s_ext_blocks += ee_len; |
| sbi->s_ext_extents++; |
| if (ee_len < sbi->s_ext_min) |
| sbi->s_ext_min = ee_len; |
| if (ee_len > sbi->s_ext_max) |
| sbi->s_ext_max = ee_len; |
| if (ext_depth(inode) > sbi->s_depth_max) |
| sbi->s_depth_max = ext_depth(inode); |
| spin_unlock(&sbi->s_ext_stats_lock); |
| } |
| #endif |
| if (from >= le32_to_cpu(ex->ee_block) |
| && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { |
| /* tail removal */ |
| ext4_lblk_t num; |
| ext4_fsblk_t start; |
| |
| num = le32_to_cpu(ex->ee_block) + ee_len - from; |
| start = ext_pblock(ex) + ee_len - num; |
| ext_debug("free last %u blocks starting %llu\n", num, start); |
| for (i = 0; i < num; i++) { |
| bh = sb_find_get_block(inode->i_sb, start + i); |
| ext4_forget(handle, 0, inode, bh, start + i); |
| } |
| ext4_free_blocks(handle, inode, start, num, metadata); |
| } else if (from == le32_to_cpu(ex->ee_block) |
| && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) { |
| printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n", |
| from, to, le32_to_cpu(ex->ee_block), ee_len); |
| } else { |
| printk(KERN_INFO "strange request: removal(2) " |
| "%u-%u from %u:%u\n", |
| from, to, le32_to_cpu(ex->ee_block), ee_len); |
| } |
| return 0; |
| } |
| |
| static int |
| ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, ext4_lblk_t start) |
| { |
| int err = 0, correct_index = 0; |
| int depth = ext_depth(inode), credits; |
| struct ext4_extent_header *eh; |
| ext4_lblk_t a, b, block; |
| unsigned num; |
| ext4_lblk_t ex_ee_block; |
| unsigned short ex_ee_len; |
| unsigned uninitialized = 0; |
| struct ext4_extent *ex; |
| |
| /* the header must be checked already in ext4_ext_remove_space() */ |
| ext_debug("truncate since %u in leaf\n", start); |
| if (!path[depth].p_hdr) |
| path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); |
| eh = path[depth].p_hdr; |
| BUG_ON(eh == NULL); |
| |
| /* find where to start removing */ |
| ex = EXT_LAST_EXTENT(eh); |
| |
| ex_ee_block = le32_to_cpu(ex->ee_block); |
| if (ext4_ext_is_uninitialized(ex)) |
| uninitialized = 1; |
| ex_ee_len = ext4_ext_get_actual_len(ex); |
| |
| while (ex >= EXT_FIRST_EXTENT(eh) && |
| ex_ee_block + ex_ee_len > start) { |
| ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len); |
| path[depth].p_ext = ex; |
| |
| a = ex_ee_block > start ? ex_ee_block : start; |
| b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? |
| ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; |
| |
| ext_debug(" border %u:%u\n", a, b); |
| |
| if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { |
| block = 0; |
| num = 0; |
| BUG(); |
| } else if (a != ex_ee_block) { |
| /* remove tail of the extent */ |
| block = ex_ee_block; |
| num = a - block; |
| } else if (b != ex_ee_block + ex_ee_len - 1) { |
| /* remove head of the extent */ |
| block = a; |
| num = b - a; |
| /* there is no "make a hole" API yet */ |
| BUG(); |
| } else { |
| /* remove whole extent: excellent! */ |
| block = ex_ee_block; |
| num = 0; |
| BUG_ON(a != ex_ee_block); |
| BUG_ON(b != ex_ee_block + ex_ee_len - 1); |
| } |
| |
| /* at present, extent can't cross block group: */ |
| /* leaf + bitmap + group desc + sb + inode */ |
| credits = 5; |
| if (ex == EXT_FIRST_EXTENT(eh)) { |
| correct_index = 1; |
| credits += (ext_depth(inode)) + 1; |
| } |
| #ifdef CONFIG_QUOTA |
| credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); |
| #endif |
| |
| handle = ext4_ext_journal_restart(handle, credits); |
| if (IS_ERR(handle)) { |
| err = PTR_ERR(handle); |
| goto out; |
| } |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| err = ext4_remove_blocks(handle, inode, ex, a, b); |
| if (err) |
| goto out; |
| |
| if (num == 0) { |
| /* this extent is removed; mark slot entirely unused */ |
| ext4_ext_store_pblock(ex, 0); |
| le16_add_cpu(&eh->eh_entries, -1); |
| } |
| |
| ex->ee_block = cpu_to_le32(block); |
| ex->ee_len = cpu_to_le16(num); |
| /* |
| * Do not mark uninitialized if all the blocks in the |
| * extent have been removed. |
| */ |
| if (uninitialized && num) |
| ext4_ext_mark_uninitialized(ex); |
| |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| ext_debug("new extent: %u:%u:%llu\n", block, num, |
| ext_pblock(ex)); |
| ex--; |
| ex_ee_block = le32_to_cpu(ex->ee_block); |
| ex_ee_len = ext4_ext_get_actual_len(ex); |
| } |
| |
| if (correct_index && eh->eh_entries) |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| |
| /* if this leaf is free, then we should |
| * remove it from index block above */ |
| if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) |
| err = ext4_ext_rm_idx(handle, inode, path + depth); |
| |
| out: |
| return err; |
| } |
| |
| /* |
| * ext4_ext_more_to_rm: |
| * returns 1 if current index has to be freed (even partial) |
| */ |
| static int |
| ext4_ext_more_to_rm(struct ext4_ext_path *path) |
| { |
| BUG_ON(path->p_idx == NULL); |
| |
| if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) |
| return 0; |
| |
| /* |
| * if truncate on deeper level happened, it wasn't partial, |
| * so we have to consider current index for truncation |
| */ |
| if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) |
| return 0; |
| return 1; |
| } |
| |
| static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) |
| { |
| struct super_block *sb = inode->i_sb; |
| int depth = ext_depth(inode); |
| struct ext4_ext_path *path; |
| handle_t *handle; |
| int i = 0, err = 0; |
| |
| ext_debug("truncate since %u\n", start); |
| |
| /* probably first extent we're gonna free will be last in block */ |
| handle = ext4_journal_start(inode, depth + 1); |
| if (IS_ERR(handle)) |
| return PTR_ERR(handle); |
| |
| ext4_ext_invalidate_cache(inode); |
| |
| /* |
| * We start scanning from right side, freeing all the blocks |
| * after i_size and walking into the tree depth-wise. |
| */ |
| path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL); |
| if (path == NULL) { |
| ext4_journal_stop(handle); |
| return -ENOMEM; |
| } |
| path[0].p_hdr = ext_inode_hdr(inode); |
| if (ext4_ext_check_header(inode, path[0].p_hdr, depth)) { |
| err = -EIO; |
| goto out; |
| } |
| path[0].p_depth = depth; |
| |
| while (i >= 0 && err == 0) { |
| if (i == depth) { |
| /* this is leaf block */ |
| err = ext4_ext_rm_leaf(handle, inode, path, start); |
| /* root level has p_bh == NULL, brelse() eats this */ |
| brelse(path[i].p_bh); |
| path[i].p_bh = NULL; |
| i--; |
| continue; |
| } |
| |
| /* this is index block */ |
| if (!path[i].p_hdr) { |
| ext_debug("initialize header\n"); |
| path[i].p_hdr = ext_block_hdr(path[i].p_bh); |
| } |
| |
| if (!path[i].p_idx) { |
| /* this level hasn't been touched yet */ |
| path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); |
| path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; |
| ext_debug("init index ptr: hdr 0x%p, num %d\n", |
| path[i].p_hdr, |
| le16_to_cpu(path[i].p_hdr->eh_entries)); |
| } else { |
| /* we were already here, see at next index */ |
| path[i].p_idx--; |
| } |
| |
| ext_debug("level %d - index, first 0x%p, cur 0x%p\n", |
| i, EXT_FIRST_INDEX(path[i].p_hdr), |
| path[i].p_idx); |
| if (ext4_ext_more_to_rm(path + i)) { |
| struct buffer_head *bh; |
| /* go to the next level */ |
| ext_debug("move to level %d (block %llu)\n", |
| i + 1, idx_pblock(path[i].p_idx)); |
| memset(path + i + 1, 0, sizeof(*path)); |
| bh = sb_bread(sb, idx_pblock(path[i].p_idx)); |
| if (!bh) { |
| /* should we reset i_size? */ |
| err = -EIO; |
| break; |
| } |
| if (WARN_ON(i + 1 > depth)) { |
| err = -EIO; |
| break; |
| } |
| if (ext4_ext_check_header(inode, ext_block_hdr(bh), |
| depth - i - 1)) { |
| err = -EIO; |
| break; |
| } |
| path[i + 1].p_bh = bh; |
| |
| /* save actual number of indexes since this |
| * number is changed at the next iteration */ |
| path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); |
| i++; |
| } else { |
| /* we finished processing this index, go up */ |
| if (path[i].p_hdr->eh_entries == 0 && i > 0) { |
| /* index is empty, remove it; |
| * handle must be already prepared by the |
| * truncatei_leaf() */ |
| err = ext4_ext_rm_idx(handle, inode, path + i); |
| } |
| /* root level has p_bh == NULL, brelse() eats this */ |
| brelse(path[i].p_bh); |
| path[i].p_bh = NULL; |
| i--; |
| ext_debug("return to level %d\n", i); |
| } |
| } |
| |
| /* TODO: flexible tree reduction should be here */ |
| if (path->p_hdr->eh_entries == 0) { |
| /* |
| * truncate to zero freed all the tree, |
| * so we need to correct eh_depth |
| */ |
| err = ext4_ext_get_access(handle, inode, path); |
| if (err == 0) { |
| ext_inode_hdr(inode)->eh_depth = 0; |
| ext_inode_hdr(inode)->eh_max = |
| cpu_to_le16(ext4_ext_space_root(inode)); |
| err = ext4_ext_dirty(handle, inode, path); |
| } |
| } |
| out: |
| ext4_ext_tree_changed(inode); |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| ext4_journal_stop(handle); |
| |
| return err; |
| } |
| |
| /* |
| * called at mount time |
| */ |
| void ext4_ext_init(struct super_block *sb) |
| { |
| /* |
| * possible initialization would be here |
| */ |
| |
| if (test_opt(sb, EXTENTS)) { |
| printk("EXT4-fs: file extents enabled"); |
| #ifdef AGGRESSIVE_TEST |
| printk(", aggressive tests"); |
| #endif |
| #ifdef CHECK_BINSEARCH |
| printk(", check binsearch"); |
| #endif |
| #ifdef EXTENTS_STATS |
| printk(", stats"); |
| #endif |
| printk("\n"); |
| #ifdef EXTENTS_STATS |
| spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); |
| EXT4_SB(sb)->s_ext_min = 1 << 30; |
| EXT4_SB(sb)->s_ext_max = 0; |
| #endif |
| } |
| } |
| |
| /* |
| * called at umount time |
| */ |
| void ext4_ext_release(struct super_block *sb) |
| { |
| if (!test_opt(sb, EXTENTS)) |
| return; |
| |
| #ifdef EXTENTS_STATS |
| if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", |
| sbi->s_ext_blocks, sbi->s_ext_extents, |
| sbi->s_ext_blocks / sbi->s_ext_extents); |
| printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", |
| sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); |
| } |
| #endif |
| } |
| |
| static void bi_complete(struct bio *bio, int error) |
| { |
| complete((struct completion *)bio->bi_private); |
| } |
| |
| /* FIXME!! we need to try to merge to left or right after zero-out */ |
| static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) |
| { |
| int ret = -EIO; |
| struct bio *bio; |
| int blkbits, blocksize; |
| sector_t ee_pblock; |
| struct completion event; |
| unsigned int ee_len, len, done, offset; |
| |
| |
| blkbits = inode->i_blkbits; |
| blocksize = inode->i_sb->s_blocksize; |
| ee_len = ext4_ext_get_actual_len(ex); |
| ee_pblock = ext_pblock(ex); |
| |
| /* convert ee_pblock to 512 byte sectors */ |
| ee_pblock = ee_pblock << (blkbits - 9); |
| |
| while (ee_len > 0) { |
| |
| if (ee_len > BIO_MAX_PAGES) |
| len = BIO_MAX_PAGES; |
| else |
| len = ee_len; |
| |
| bio = bio_alloc(GFP_NOIO, len); |
| if (!bio) |
| return -ENOMEM; |
| bio->bi_sector = ee_pblock; |
| bio->bi_bdev = inode->i_sb->s_bdev; |
| |
| done = 0; |
| offset = 0; |
| while (done < len) { |
| ret = bio_add_page(bio, ZERO_PAGE(0), |
| blocksize, offset); |
| if (ret != blocksize) { |
| /* |
| * We can't add any more pages because of |
| * hardware limitations. Start a new bio. |
| */ |
| break; |
| } |
| done++; |
| offset += blocksize; |
| if (offset >= PAGE_CACHE_SIZE) |
| offset = 0; |
| } |
| |
| init_completion(&event); |
| bio->bi_private = &event; |
| bio->bi_end_io = bi_complete; |
| submit_bio(WRITE, bio); |
| wait_for_completion(&event); |
| |
| if (test_bit(BIO_UPTODATE, &bio->bi_flags)) |
| ret = 0; |
| else { |
| ret = -EIO; |
| break; |
| } |
| bio_put(bio); |
| ee_len -= done; |
| ee_pblock += done << (blkbits - 9); |
| } |
| return ret; |
| } |
| |
| #define EXT4_EXT_ZERO_LEN 7 |
| |
| /* |
| * This function is called by ext4_ext_get_blocks() if someone tries to write |
| * to an uninitialized extent. It may result in splitting the uninitialized |
| * extent into multiple extents (upto three - one initialized and two |
| * uninitialized). |
| * There are three possibilities: |
| * a> There is no split required: Entire extent should be initialized |
| * b> Splits in two extents: Write is happening at either end of the extent |
| * c> Splits in three extents: Somone is writing in middle of the extent |
| */ |
| static int ext4_ext_convert_to_initialized(handle_t *handle, |
| struct inode *inode, |
| struct ext4_ext_path *path, |
| ext4_lblk_t iblock, |
| unsigned long max_blocks) |
| { |
| struct ext4_extent *ex, newex, orig_ex; |
| struct ext4_extent *ex1 = NULL; |
| struct ext4_extent *ex2 = NULL; |
| struct ext4_extent *ex3 = NULL; |
| struct ext4_extent_header *eh; |
| ext4_lblk_t ee_block; |
| unsigned int allocated, ee_len, depth; |
| ext4_fsblk_t newblock; |
| int err = 0; |
| int ret = 0; |
| |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| ex = path[depth].p_ext; |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| allocated = ee_len - (iblock - ee_block); |
| newblock = iblock - ee_block + ext_pblock(ex); |
| ex2 = ex; |
| orig_ex.ee_block = ex->ee_block; |
| orig_ex.ee_len = cpu_to_le16(ee_len); |
| ext4_ext_store_pblock(&orig_ex, ext_pblock(ex)); |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */ |
| if (ee_len <= 2*EXT4_EXT_ZERO_LEN) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zeroed the full extent */ |
| return allocated; |
| } |
| |
| /* ex1: ee_block to iblock - 1 : uninitialized */ |
| if (iblock > ee_block) { |
| ex1 = ex; |
| ex1->ee_len = cpu_to_le16(iblock - ee_block); |
| ext4_ext_mark_uninitialized(ex1); |
| ex2 = &newex; |
| } |
| /* |
| * for sanity, update the length of the ex2 extent before |
| * we insert ex3, if ex1 is NULL. This is to avoid temporary |
| * overlap of blocks. |
| */ |
| if (!ex1 && allocated > max_blocks) |
| ex2->ee_len = cpu_to_le16(max_blocks); |
| /* ex3: to ee_block + ee_len : uninitialised */ |
| if (allocated > max_blocks) { |
| unsigned int newdepth; |
| /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */ |
| if (allocated <= EXT4_EXT_ZERO_LEN) { |
| /* Mark first half uninitialized. |
| * Mark second half initialized and zero out the |
| * initialized extent |
| */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = cpu_to_le16(ee_len - allocated); |
| ext4_ext_mark_uninitialized(ex); |
| ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| |
| ex3 = &newex; |
| ex3->ee_block = cpu_to_le32(iblock); |
| ext4_ext_store_pblock(ex3, newblock); |
| ex3->ee_len = cpu_to_le16(allocated); |
| err = ext4_ext_insert_extent(handle, inode, path, ex3); |
| if (err == -ENOSPC) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zeroed the full extent */ |
| return allocated; |
| |
| } else if (err) |
| goto fix_extent_len; |
| |
| /* |
| * We need to zero out the second half because |
| * an fallocate request can update file size and |
| * converting the second half to initialized extent |
| * implies that we can leak some junk data to user |
| * space. |
| */ |
| err = ext4_ext_zeroout(inode, ex3); |
| if (err) { |
| /* |
| * We should actually mark the |
| * second half as uninit and return error |
| * Insert would have changed the extent |
| */ |
| depth = ext_depth(inode); |
| ext4_ext_drop_refs(path); |
| path = ext4_ext_find_extent(inode, |
| iblock, path); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| return err; |
| } |
| ex = path[depth].p_ext; |
| err = ext4_ext_get_access(handle, inode, |
| path + depth); |
| if (err) |
| return err; |
| ext4_ext_mark_uninitialized(ex); |
| ext4_ext_dirty(handle, inode, path + depth); |
| return err; |
| } |
| |
| /* zeroed the second half */ |
| return allocated; |
| } |
| ex3 = &newex; |
| ex3->ee_block = cpu_to_le32(iblock + max_blocks); |
| ext4_ext_store_pblock(ex3, newblock + max_blocks); |
| ex3->ee_len = cpu_to_le16(allocated - max_blocks); |
| ext4_ext_mark_uninitialized(ex3); |
| err = ext4_ext_insert_extent(handle, inode, path, ex3); |
| if (err == -ENOSPC) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zeroed the full extent */ |
| return allocated; |
| |
| } else if (err) |
| goto fix_extent_len; |
| /* |
| * The depth, and hence eh & ex might change |
| * as part of the insert above. |
| */ |
| newdepth = ext_depth(inode); |
| /* |
| * update the extent length after successfull insert of the |
| * split extent |
| */ |
| orig_ex.ee_len = cpu_to_le16(ee_len - |
| ext4_ext_get_actual_len(ex3)); |
| if (newdepth != depth) { |
| depth = newdepth; |
| ext4_ext_drop_refs(path); |
| path = ext4_ext_find_extent(inode, iblock, path); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| goto out; |
| } |
| eh = path[depth].p_hdr; |
| ex = path[depth].p_ext; |
| if (ex2 != &newex) |
| ex2 = ex; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| } |
| allocated = max_blocks; |
| |
| /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying |
| * to insert a extent in the middle zerout directly |
| * otherwise give the extent a chance to merge to left |
| */ |
| if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN && |
| iblock != ee_block) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zero out the first half */ |
| return allocated; |
| } |
| } |
| /* |
| * If there was a change of depth as part of the |
| * insertion of ex3 above, we need to update the length |
| * of the ex1 extent again here |
| */ |
| if (ex1 && ex1 != ex) { |
| ex1 = ex; |
| ex1->ee_len = cpu_to_le16(iblock - ee_block); |
| ext4_ext_mark_uninitialized(ex1); |
| ex2 = &newex; |
| } |
| /* ex2: iblock to iblock + maxblocks-1 : initialised */ |
| ex2->ee_block = cpu_to_le32(iblock); |
| ext4_ext_store_pblock(ex2, newblock); |
| ex2->ee_len = cpu_to_le16(allocated); |
| if (ex2 != ex) |
| goto insert; |
| /* |
| * New (initialized) extent starts from the first block |
| * in the current extent. i.e., ex2 == ex |
| * We have to see if it can be merged with the extent |
| * on the left. |
| */ |
| if (ex2 > EXT_FIRST_EXTENT(eh)) { |
| /* |
| * To merge left, pass "ex2 - 1" to try_to_merge(), |
| * since it merges towards right _only_. |
| */ |
| ret = ext4_ext_try_to_merge(inode, path, ex2 - 1); |
| if (ret) { |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| if (err) |
| goto out; |
| depth = ext_depth(inode); |
| ex2--; |
| } |
| } |
| /* |
| * Try to Merge towards right. This might be required |
| * only when the whole extent is being written to. |
| * i.e. ex2 == ex and ex3 == NULL. |
| */ |
| if (!ex3) { |
| ret = ext4_ext_try_to_merge(inode, path, ex2); |
| if (ret) { |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| if (err) |
| goto out; |
| } |
| } |
| /* Mark modified extent as dirty */ |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| goto out; |
| insert: |
| err = ext4_ext_insert_extent(handle, inode, path, &newex); |
| if (err == -ENOSPC) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zero out the first half */ |
| return allocated; |
| } else if (err) |
| goto fix_extent_len; |
| out: |
| return err ? err : allocated; |
| |
| fix_extent_len: |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext_pblock(&orig_ex)); |
| ext4_ext_mark_uninitialized(ex); |
| ext4_ext_dirty(handle, inode, path + depth); |
| return err; |
| } |
| |
| /* |
| * Block allocation/map/preallocation routine for extents based files |
| * |
| * |
| * Need to be called with |
| * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block |
| * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) |
| * |
| * return > 0, number of of blocks already mapped/allocated |
| * if create == 0 and these are pre-allocated blocks |
| * buffer head is unmapped |
| * otherwise blocks are mapped |
| * |
| * return = 0, if plain look up failed (blocks have not been allocated) |
| * buffer head is unmapped |
| * |
| * return < 0, error case. |
| */ |
| int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, |
| ext4_lblk_t iblock, |
| unsigned long max_blocks, struct buffer_head *bh_result, |
| int create, int extend_disksize) |
| { |
| struct ext4_ext_path *path = NULL; |
| struct ext4_extent_header *eh; |
| struct ext4_extent newex, *ex; |
| ext4_fsblk_t goal, newblock; |
| int err = 0, depth, ret; |
| unsigned long allocated = 0; |
| struct ext4_allocation_request ar; |
| |
| __clear_bit(BH_New, &bh_result->b_state); |
| ext_debug("blocks %u/%lu requested for inode %u\n", |
| iblock, max_blocks, inode->i_ino); |
| |
| /* check in cache */ |
| goal = ext4_ext_in_cache(inode, iblock, &newex); |
| if (goal) { |
| if (goal == EXT4_EXT_CACHE_GAP) { |
| if (!create) { |
| /* |
| * block isn't allocated yet and |
| * user doesn't want to allocate it |
| */ |
| goto out2; |
| } |
| /* we should allocate requested block */ |
| } else if (goal == EXT4_EXT_CACHE_EXTENT) { |
| /* block is already allocated */ |
| newblock = iblock |
| - le32_to_cpu(newex.ee_block) |
| + ext_pblock(&newex); |
| /* number of remaining blocks in the extent */ |
| allocated = ext4_ext_get_actual_len(&newex) - |
| (iblock - le32_to_cpu(newex.ee_block)); |
| goto out; |
| } else { |
| BUG(); |
| } |
| } |
| |
| /* find extent for this block */ |
| path = ext4_ext_find_extent(inode, iblock, NULL); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| path = NULL; |
| goto out2; |
| } |
| |
| depth = ext_depth(inode); |
| |
| /* |
| * consistent leaf must not be empty; |
| * this situation is possible, though, _during_ tree modification; |
| * this is why assert can't be put in ext4_ext_find_extent() |
| */ |
| BUG_ON(path[depth].p_ext == NULL && depth != 0); |
| eh = path[depth].p_hdr; |
| |
| ex = path[depth].p_ext; |
| if (ex) { |
| ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); |
| ext4_fsblk_t ee_start = ext_pblock(ex); |
| unsigned short ee_len; |
| |
| /* |
| * Uninitialized extents are treated as holes, except that |
| * we split out initialized portions during a write. |
| */ |
| ee_len = ext4_ext_get_actual_len(ex); |
| /* if found extent covers block, simply return it */ |
| if (iblock >= ee_block && iblock < ee_block + ee_len) { |
| newblock = iblock - ee_block + ee_start; |
| /* number of remaining blocks in the extent */ |
| allocated = ee_len - (iblock - ee_block); |
| ext_debug("%u fit into %lu:%d -> %llu\n", iblock, |
| 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, |
| EXT4_EXT_CACHE_EXTENT); |
| goto out; |
| } |
| if (create == EXT4_CREATE_UNINITIALIZED_EXT) |
| goto out; |
| if (!create) { |
| /* |
| * We have blocks reserved already. We |
| * return allocated blocks so that delalloc |
| * won't do block reservation for us. But |
| * the buffer head will be unmapped so that |
| * a read from the block returns 0s. |
| */ |
| if (allocated > max_blocks) |
| allocated = max_blocks; |
| /* mark the buffer unwritten */ |
| __set_bit(BH_Unwritten, &bh_result->b_state); |
| goto out2; |
| } |
| |
| ret = ext4_ext_convert_to_initialized(handle, inode, |
| path, iblock, |
| max_blocks); |
| if (ret <= 0) { |
| err = ret; |
| goto out2; |
| } else |
| allocated = ret; |
| goto outnew; |
| } |
| } |
| |
| /* |
| * requested block isn't allocated yet; |
| * we couldn't try to create block if create flag is zero |
| */ |
| if (!create) { |
| /* |
| * put just found gap into cache to speed up |
| * subsequent requests |
| */ |
| ext4_ext_put_gap_in_cache(inode, path, iblock); |
| goto out2; |
| } |
| /* |
| * Okay, we need to do block allocation. Lazily initialize the block |
| * allocation info here if necessary. |
| */ |
| if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info)) |
| ext4_init_block_alloc_info(inode); |
| |
| /* find neighbour allocated blocks */ |
| ar.lleft = iblock; |
| err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); |
| if (err) |
| goto out2; |
| ar.lright = iblock; |
| err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright); |
| if (err) |
| goto out2; |
| |
| /* |
| * See if request is beyond maximum number of blocks we can have in |
| * a single extent. For an initialized extent this limit is |
| * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is |
| * EXT_UNINIT_MAX_LEN. |
| */ |
| if (max_blocks > EXT_INIT_MAX_LEN && |
| create != EXT4_CREATE_UNINITIALIZED_EXT) |
| max_blocks = EXT_INIT_MAX_LEN; |
| else if (max_blocks > EXT_UNINIT_MAX_LEN && |
| create == EXT4_CREATE_UNINITIALIZED_EXT) |
| max_blocks = EXT_UNINIT_MAX_LEN; |
| |
| /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */ |
| newex.ee_block = cpu_to_le32(iblock); |
| newex.ee_len = cpu_to_le16(max_blocks); |
| err = ext4_ext_check_overlap(inode, &newex, path); |
| if (err) |
| allocated = ext4_ext_get_actual_len(&newex); |
| else |
| allocated = max_blocks; |
| |
| /* allocate new block */ |
| ar.inode = inode; |
| ar.goal = ext4_ext_find_goal(inode, path, iblock); |
| ar.logical = iblock; |
| ar.len = allocated; |
| if (S_ISREG(inode->i_mode)) |
| ar.flags = EXT4_MB_HINT_DATA; |
| else |
| /* disable in-core preallocation for non-regular files */ |
| ar.flags = 0; |
| newblock = ext4_mb_new_blocks(handle, &ar, &err); |
| if (!newblock) |
| goto out2; |
| ext_debug("allocate new block: goal %llu, found %llu/%lu\n", |
| goal, newblock, allocated); |
| |
| /* try to insert new extent into found leaf and return */ |
| ext4_ext_store_pblock(&newex, newblock); |
| newex.ee_len = cpu_to_le16(ar.len); |
| if (create == EXT4_CREATE_UNINITIALIZED_EXT) /* Mark uninitialized */ |
| ext4_ext_mark_uninitialized(&newex); |
| err = ext4_ext_insert_extent(handle, inode, path, &newex); |
| if (err) { |
| /* free data blocks we just allocated */ |
| /* not a good idea to call discard here directly, |
| * but otherwise we'd need to call it every free() */ |
| ext4_mb_discard_inode_preallocations(inode); |
| ext4_free_blocks(handle, inode, ext_pblock(&newex), |
| ext4_ext_get_actual_len(&newex), 0); |
| goto out2; |
| } |
| |
| if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize) |
| EXT4_I(inode)->i_disksize = inode->i_size; |
| |
| /* previous routine could use block we allocated */ |
| newblock = ext_pblock(&newex); |
| allocated = ext4_ext_get_actual_len(&newex); |
| outnew: |
| __set_bit(BH_New, &bh_result->b_state); |
| |
| /* Cache only when it is _not_ an uninitialized extent */ |
| if (create != EXT4_CREATE_UNINITIALIZED_EXT) |
| ext4_ext_put_in_cache(inode, iblock, allocated, newblock, |
| EXT4_EXT_CACHE_EXTENT); |
| out: |
| if (allocated > max_blocks) |
| allocated = max_blocks; |
| ext4_ext_show_leaf(inode, path); |
| __set_bit(BH_Mapped, &bh_result->b_state); |
| bh_result->b_bdev = inode->i_sb->s_bdev; |
| bh_result->b_blocknr = newblock; |
| out2: |
| if (path) { |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| } |
| return err ? err : allocated; |
| } |
| |
| void ext4_ext_truncate(struct inode * inode, struct page *page) |
| { |
| struct address_space *mapping = inode->i_mapping; |
| struct super_block *sb = inode->i_sb; |
| ext4_lblk_t last_block; |
| handle_t *handle; |
| int err = 0; |
| |
| /* |
| * probably first extent we're gonna free will be last in block |
| */ |
| err = ext4_writepage_trans_blocks(inode) + 3; |
| handle = ext4_journal_start(inode, err); |
| if (IS_ERR(handle)) { |
| if (page) { |
| clear_highpage(page); |
| flush_dcache_page(page); |
| unlock_page(page); |
| page_cache_release(page); |
| } |
| return; |
| } |
| |
| if (page) |
| ext4_block_truncate_page(handle, page, mapping, inode->i_size); |
| |
| down_write(&EXT4_I(inode)->i_data_sem); |
| ext4_ext_invalidate_cache(inode); |
| |
| ext4_mb_discard_inode_preallocations(inode); |
| |
| /* |
| * TODO: optimization is possible here. |
| * Probably we need not scan at all, |
| * because page truncation is enough. |
| */ |
| if (ext4_orphan_add(handle, inode)) |
| goto out_stop; |
| |
| /* we have to know where to truncate from in crash case */ |
| EXT4_I(inode)->i_disksize = inode->i_size; |
| ext4_mark_inode_dirty(handle, inode); |
| |
| last_block = (inode->i_size + sb->s_blocksize - 1) |
| >> EXT4_BLOCK_SIZE_BITS(sb); |
| err = ext4_ext_remove_space(inode, last_block); |
| |
| /* In a multi-transaction truncate, we only make the final |
| * transaction synchronous. |
| */ |
| if (IS_SYNC(inode)) |
| handle->h_sync = 1; |
| |
| 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); |
| |
| up_write(&EXT4_I(inode)->i_data_sem); |
| ext4_journal_stop(handle); |
| } |
| |
| /* |
| * ext4_ext_writepage_trans_blocks: |
| * calculate max number of blocks we could modify |
| * in order to allocate new block for an inode |
| */ |
| int ext4_ext_writepage_trans_blocks(struct inode *inode, int num) |
| { |
| int needed; |
| |
| needed = ext4_ext_calc_credits_for_insert(inode, NULL); |
| |
| /* caller wants to allocate num blocks, but note it includes sb */ |
| needed = needed * num - (num - 1); |
| |
| #ifdef CONFIG_QUOTA |
| needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); |
| #endif |
| |
| return needed; |
| } |
| |
| static void ext4_falloc_update_inode(struct inode *inode, |
| int mode, loff_t new_size, int update_ctime) |
| { |
| struct timespec now; |
| |
| if (update_ctime) { |
| now = current_fs_time(inode->i_sb); |
| if (!timespec_equal(&inode->i_ctime, &now)) |
| inode->i_ctime = now; |
| } |
| /* |
| * Update only when preallocation was requested beyond |
| * the file size. |
| */ |
| if (!(mode & FALLOC_FL_KEEP_SIZE) && |
| new_size > i_size_read(inode)) { |
| i_size_write(inode, new_size); |
| EXT4_I(inode)->i_disksize = new_size; |
| } |
| |
| } |
| |
| /* |
| * preallocate space for a file. This implements ext4's fallocate inode |
| * operation, which gets called from sys_fallocate system call. |
| * For block-mapped files, posix_fallocate should fall back to the method |
| * of writing zeroes to the required new blocks (the same behavior which is |
| * expected for file systems which do not support fallocate() system call). |
| */ |
| long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len) |
| { |
| handle_t *handle; |
| ext4_lblk_t block; |
| loff_t new_size; |
| unsigned long max_blocks; |
| int ret = 0; |
| int ret2 = 0; |
| int retries = 0; |
| struct buffer_head map_bh; |
| unsigned int credits, blkbits = inode->i_blkbits; |
| |
| /* |
| * currently supporting (pre)allocate mode for extent-based |
| * files _only_ |
| */ |
| if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) |
| return -EOPNOTSUPP; |
| |
| /* preallocation to directories is currently not supported */ |
| if (S_ISDIR(inode->i_mode)) |
| return -ENODEV; |
| |
| block = offset >> blkbits; |
| /* |
| * We can't just convert len to max_blocks because |
| * If blocksize = 4096 offset = 3072 and len = 2048 |
| */ |
| max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) |
| - block; |
| /* |
| * credits to insert 1 extent into extent tree + buffers to be able to |
| * modify 1 super block, 1 block bitmap and 1 group descriptor. |
| */ |
| credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3; |
| mutex_lock(&inode->i_mutex); |
| retry: |
| while (ret >= 0 && ret < max_blocks) { |
| block = block + ret; |
| max_blocks = max_blocks - ret; |
| handle = ext4_journal_start(inode, credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| break; |
| } |
| ret = ext4_get_blocks_wrap(handle, inode, block, |
| max_blocks, &map_bh, |
| EXT4_CREATE_UNINITIALIZED_EXT, 0); |
| if (ret <= 0) { |
| #ifdef EXT4FS_DEBUG |
| WARN_ON(ret <= 0); |
| printk(KERN_ERR "%s: ext4_ext_get_blocks " |
| "returned error inode#%lu, block=%u, " |
| "max_blocks=%lu", __func__, |
| inode->i_ino, block, max_blocks); |
| #endif |
| ext4_mark_inode_dirty(handle, inode); |
| ret2 = ext4_journal_stop(handle); |
| break; |
| } |
| if ((block + ret) >= (EXT4_BLOCK_ALIGN(offset + len, |
| blkbits) >> blkbits)) |
| new_size = offset + len; |
| else |
| new_size = (block + ret) << blkbits; |
| |
| ext4_falloc_update_inode(inode, mode, new_size, |
| buffer_new(&map_bh)); |
| ext4_mark_inode_dirty(handle, inode); |
| ret2 = ext4_journal_stop(handle); |
| if (ret2) |
| break; |
| } |
| if (ret == -ENOSPC && |
| ext4_should_retry_alloc(inode->i_sb, &retries)) { |
| ret = 0; |
| goto retry; |
| } |
| mutex_unlock(&inode->i_mutex); |
| return ret > 0 ? ret2 : ret; |
| } |