/fs/ext4/extents.c
C | 1974 lines | 1432 code | 237 blank | 305 comment | 312 complexity | c034bc4ecbb4795f9345db3ce29f9973 MD5 | raw file
- /*
- * 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/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 <asm/uaccess.h>
- #include <linux/fiemap.h>
- #include "ext4_jbd2.h"
- #include "ext4_extents.h"
- #include <trace/events/ext4.h>
- static int ext4_split_extent(handle_t *handle,
- struct inode *inode,
- struct ext4_ext_path *path,
- struct ext4_map_blocks *map,
- int split_flag,
- int flags);
- static int ext4_ext_truncate_extend_restart(handle_t *handle,
- struct inode *inode,
- int needed)
- {
- int err;
- if (!ext4_handle_valid(handle))
- return 0;
- if (handle->h_buffer_credits > needed)
- return 0;
- err = ext4_journal_extend(handle, needed);
- if (err <= 0)
- return err;
- err = ext4_truncate_restart_trans(handle, inode, needed);
- if (err == 0)
- err = -EAGAIN;
- return err;
- }
- /*
- * 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_handle_dirty_metadata(handle, inode, 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)
- {
- int depth;
- if (path) {
- struct ext4_extent *ex;
- depth = path->p_depth;
- /*
- * Try to predict block placement assuming that we are
- * filling in a file which will eventually be
- * non-sparse --- i.e., in the case of libbfd writing
- * an ELF object sections out-of-order but in a way
- * the eventually results in a contiguous object or
- * executable file, or some database extending a table
- * space file. However, this is actually somewhat
- * non-ideal if we are writing a sparse file such as
- * qemu or KVM writing a raw image file that is going
- * to stay fairly sparse, since it will end up
- * fragmenting the file system's free space. Maybe we
- * should have some hueristics or some way to allow
- * userspace to pass a hint to file system,
- * especially if the latter case turns out to be
- * common.
- */
- ex = path[depth].p_ext;
- if (ex) {
- ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
- ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
- if (block > ext_block)
- return ext_pblk + (block - ext_block);
- else
- return ext_pblk - (ext_block - 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 */
- return ext4_inode_to_goal_block(inode);
- }
- /*
- * Allocation for a meta data block
- */
- static ext4_fsblk_t
- ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
- struct ext4_ext_path *path,
- struct ext4_extent *ex, int *err, unsigned int flags)
- {
- ext4_fsblk_t goal, newblock;
- goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
- newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
- NULL, err);
- return newblock;
- }
- static inline int ext4_ext_space_block(struct inode *inode, int check)
- {
- int size;
- size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
- / sizeof(struct ext4_extent);
- if (!check) {
- #ifdef AGGRESSIVE_TEST
- if (size > 6)
- size = 6;
- #endif
- }
- return size;
- }
- static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
- {
- int size;
- size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
- / sizeof(struct ext4_extent_idx);
- if (!check) {
- #ifdef AGGRESSIVE_TEST
- if (size > 5)
- size = 5;
- #endif
- }
- return size;
- }
- static inline int ext4_ext_space_root(struct inode *inode, int check)
- {
- int size;
- size = sizeof(EXT4_I(inode)->i_data);
- size -= sizeof(struct ext4_extent_header);
- size /= sizeof(struct ext4_extent);
- if (!check) {
- #ifdef AGGRESSIVE_TEST
- if (size > 3)
- size = 3;
- #endif
- }
- return size;
- }
- static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
- {
- int size;
- size = sizeof(EXT4_I(inode)->i_data);
- size -= sizeof(struct ext4_extent_header);
- size /= sizeof(struct ext4_extent_idx);
- if (!check) {
- #ifdef AGGRESSIVE_TEST
- if (size > 4)
- size = 4;
- #endif
- }
- return size;
- }
- /*
- * Calculate the number of metadata blocks needed
- * to allocate @blocks
- * Worse case is one block per extent
- */
- int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
- {
- struct ext4_inode_info *ei = EXT4_I(inode);
- int idxs, num = 0;
- idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
- / sizeof(struct ext4_extent_idx));
- /*
- * If the new delayed allocation block is contiguous with the
- * previous da block, it can share index blocks with the
- * previous block, so we only need to allocate a new index
- * block every idxs leaf blocks. At ldxs**2 blocks, we need
- * an additional index block, and at ldxs**3 blocks, yet
- * another index blocks.
- */
- if (ei->i_da_metadata_calc_len &&
- ei->i_da_metadata_calc_last_lblock+1 == lblock) {
- if ((ei->i_da_metadata_calc_len % idxs) == 0)
- num++;
- if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
- num++;
- if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
- num++;
- ei->i_da_metadata_calc_len = 0;
- } else
- ei->i_da_metadata_calc_len++;
- ei->i_da_metadata_calc_last_lblock++;
- return num;
- }
- /*
- * In the worst case we need a new set of index blocks at
- * every level of the inode's extent tree.
- */
- ei->i_da_metadata_calc_len = 1;
- ei->i_da_metadata_calc_last_lblock = lblock;
- return ext_depth(inode) + 1;
- }
- 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, 1);
- else
- max = ext4_ext_space_root_idx(inode, 1);
- } else {
- if (depth == 0)
- max = ext4_ext_space_block(inode, 1);
- else
- max = ext4_ext_space_block_idx(inode, 1);
- }
- return max;
- }
- static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
- {
- ext4_fsblk_t block = ext4_ext_pblock(ext);
- int len = ext4_ext_get_actual_len(ext);
- return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
- }
- static int ext4_valid_extent_idx(struct inode *inode,
- struct ext4_extent_idx *ext_idx)
- {
- ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
- return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
- }
- static int ext4_valid_extent_entries(struct inode *inode,
- struct ext4_extent_header *eh,
- int depth)
- {
- struct ext4_extent *ext;
- struct ext4_extent_idx *ext_idx;
- unsigned short entries;
- if (eh->eh_entries == 0)
- return 1;
- entries = le16_to_cpu(eh->eh_entries);
- if (depth == 0) {
- /* leaf entries */
- ext = EXT_FIRST_EXTENT(eh);
- while (entries) {
- if (!ext4_valid_extent(inode, ext))
- return 0;
- ext++;
- entries--;
- }
- } else {
- ext_idx = EXT_FIRST_INDEX(eh);
- while (entries) {
- if (!ext4_valid_extent_idx(inode, ext_idx))
- return 0;
- ext_idx++;
- entries--;
- }
- }
- return 1;
- }
- static int __ext4_ext_check(const char *function, unsigned int line,
- 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;
- }
- if (!ext4_valid_extent_entries(inode, eh, depth)) {
- error_msg = "invalid extent entries";
- goto corrupted;
- }
- return 0;
- corrupted:
- ext4_error_inode(inode, function, line, 0,
- "bad header/extent: %s - magic %x, "
- "entries %u, max %u(%u), depth %u(%u)",
- 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(inode, eh, depth) \
- __ext4_ext_check(__func__, __LINE__, inode, eh, depth)
- int ext4_ext_check_inode(struct inode *inode)
- {
- return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
- }
- #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),
- ext4_idx_pblock(path->p_idx));
- } else if (path->p_ext) {
- ext_debug(" %d:[%d]%d:%llu ",
- le32_to_cpu(path->p_ext->ee_block),
- ext4_ext_is_uninitialized(path->p_ext),
- ext4_ext_get_actual_len(path->p_ext),
- ext4_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);
- ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
- for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
- ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
- ext4_ext_is_uninitialized(ex),
- ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
- }
- ext_debug("\n");
- }
- static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
- ext4_fsblk_t newblock, int level)
- {
- int depth = ext_depth(inode);
- struct ext4_extent *ex;
- if (depth != level) {
- struct ext4_extent_idx *idx;
- idx = path[level].p_idx;
- while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
- ext_debug("%d: move %d:%llu in new index %llu\n", level,
- le32_to_cpu(idx->ei_block),
- ext4_idx_pblock(idx),
- newblock);
- idx++;
- }
- return;
- }
- ex = path[depth].p_ext;
- while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
- ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
- le32_to_cpu(ex->ee_block),
- ext4_ext_pblock(ex),
- ext4_ext_is_uninitialized(ex),
- ext4_ext_get_actual_len(ex),
- newblock);
- ex++;
- }
- }
- #else
- #define ext4_ext_show_path(inode, path)
- #define ext4_ext_show_leaf(inode, path)
- #define ext4_ext_show_move(inode, path, newblock, level)
- #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),
- ext4_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(KERN_DEBUG "k=%d, ix=0x%p, "
- "first=0x%p\n", k,
- ix, EXT_FIRST_INDEX(eh));
- printk(KERN_DEBUG "%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]%d ",
- le32_to_cpu(path->p_ext->ee_block),
- ext4_ext_pblock(path->p_ext),
- ext4_ext_is_uninitialized(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, 0));
- 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);
- /* 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;
- path[0].p_bh = NULL;
- i = depth;
- /* walk through the tree */
- while (i) {
- int need_to_validate = 0;
- 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 = ext4_idx_pblock(path[ppos].p_idx);
- path[ppos].p_depth = i;
- path[ppos].p_ext = NULL;
- bh = sb_getblk(inode->i_sb, path[ppos].p_block);
- if (unlikely(!bh))
- goto err;
- if (!bh_uptodate_or_lock(bh)) {
- trace_ext4_ext_load_extent(inode, block,
- path[ppos].p_block);
- if (bh_submit_read(bh) < 0) {
- put_bh(bh);
- goto err;
- }
- /* validate the extent entries */
- need_to_validate = 1;
- }
- eh = ext_block_hdr(bh);
- ppos++;
- if (unlikely(ppos > depth)) {
- put_bh(bh);
- EXT4_ERROR_INODE(inode,
- "ppos %d > depth %d", ppos, depth);
- goto err;
- }
- path[ppos].p_bh = bh;
- path[ppos].p_hdr = eh;
- i--;
- if (need_to_validate && ext4_ext_check(inode, eh, i))
- goto err;
- }
- path[ppos].p_depth = i;
- path[ppos].p_ext = NULL;
- path[ppos].p_idx = NULL;
- /* find extent */
- ext4_ext_binsearch(inode, path + ppos, block);
- /* if not an empty leaf */
- if (path[ppos].p_ext)
- path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
- 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;
- if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
- EXT4_ERROR_INODE(inode,
- "logical %d == ei_block %d!",
- logical, le32_to_cpu(curp->p_idx->ei_block));
- return -EIO;
- }
- if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
- >= le16_to_cpu(curp->p_hdr->eh_max))) {
- EXT4_ERROR_INODE(inode,
- "eh_entries %d >= eh_max %d!",
- le16_to_cpu(curp->p_hdr->eh_entries),
- le16_to_cpu(curp->p_hdr->eh_max));
- return -EIO;
- }
- 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);
- if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
- EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
- return -EIO;
- }
- 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,
- unsigned int flags,
- 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;
- 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 */
- if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
- EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
- return -EIO;
- }
- 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_meta_block(handle, inode, path,
- newext, &err, flags);
- if (newblock == 0)
- goto cleanup;
- ablocks[a] = newblock;
- }
- /* initialize new leaf */
- newblock = ablocks[--a];
- if (unlikely(newblock == 0)) {
- EXT4_ERROR_INODE(inode, "newblock == 0!");
- err = -EIO;
- goto cleanup;
- }
- 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, 0));
- neh->eh_magic = EXT4_EXT_MAGIC;
- neh->eh_depth = 0;
- /* move remainder of path[depth] to the new leaf */
- if (unlikely(path[depth].p_hdr->eh_entries !=
- path[depth].p_hdr->eh_max)) {
- EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
- path[depth].p_hdr->eh_entries,
- path[depth].p_hdr->eh_max);
- err = -EIO;
- goto cleanup;
- }
- /* start copy from next extent */
- m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
- ext4_ext_show_move(inode, path, newblock, depth);
- if (m) {
- struct ext4_extent *ex;
- ex = EXT_FIRST_EXTENT(neh);
- memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
- le16_add_cpu(&neh->eh_entries, m);
- }
- set_buffer_uptodate(bh);
- unlock_buffer(bh);
- err = ext4_handle_dirty_metadata(handle, inode, 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;
- if (unlikely(k < 0)) {
- EXT4_ERROR_INODE(inode, "k %d < 0!", k);
- err = -EIO;
- goto cleanup;
- }
- 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, 0));
- 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);
- /* move remainder of path[i] to the new index block */
- if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
- EXT_LAST_INDEX(path[i].p_hdr))) {
- EXT4_ERROR_INODE(inode,
- "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
- le32_to_cpu(path[i].p_ext->ee_block));
- err = -EIO;
- goto cleanup;
- }
- /* start copy indexes */
- m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
- ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
- EXT_MAX_INDEX(path[i].p_hdr));
- ext4_ext_show_move(inode, path, newblock, i);
- if (m) {
- memmove(++fidx, path[i].p_idx,
- sizeof(struct ext4_extent_idx) * m);
- le16_add_cpu(&neh->eh_entries, m);
- }
- set_buffer_uptodate(bh);
- unlock_buffer(bh);
- err = ext4_handle_dirty_metadata(handle, inode, 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, NULL, ablocks[i], 1,
- EXT4_FREE_BLOCKS_METADATA);
- }
- }
- 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,
- unsigned int flags,
- struct ext4_ext_path *path,
- struct ext4_extent *newext)
- {
- struct ext4_ext_path *curp = path;
- struct ext4_extent_header *neh;
- struct buffer_head *bh;
- ext4_fsblk_t newblock;
- int err = 0;
- newblock = ext4_ext_new_meta_block(handle, inode, path,
- newext, &err, flags);
- 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, 0));
- else
- neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
- neh->eh_magic = EXT4_EXT_MAGIC;
- set_buffer_uptodate(bh);
- unlock_buffer(bh);
- err = ext4_handle_dirty_metadata(handle, inode, 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, 0));
- 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);
- 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(EXT_FIRST_INDEX(neh)->ei_block),
- ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
- 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,
- unsigned int flags,
- 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, flags, path, newext, i);
- 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);
- } else {
- /* tree is full, time to grow in depth */
- err = ext4_ext_grow_indepth(handle, inode, flags,
- 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
- */
- static 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;
- if (unlikely(path == NULL)) {
- EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
- return -EIO;
- }
- 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)) {
- if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
- EXT4_ERROR_INODE(inode,
- "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
- *logical, le32_to_cpu(ex->ee_block));
- return -EIO;
- }
- while (--depth >= 0) {
- ix = path[depth].p_idx;
- if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
- EXT4_ERROR_INODE(inode,
- "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
- ix != NULL ? ix->ei_block : 0,
- EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
- EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block : 0,
- depth);
- return -EIO;
- }
- }
- return 0;
- }
- if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
- EXT4_ERROR_INODE(inode,
- "logical %d < ee_block %d + ee_len %d!",
- *logical, le32_to_cpu(ex->ee_block), ee_len);
- return -EIO;
- }
- *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
- *phys = ext4_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
- */
- static 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; /* Note, NOT eh_depth; depth from top of tree */
- int ee_len;
- if (unlikely(path == NULL)) {
- EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
- return -EIO;
- }
- 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)) {
- if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
- EXT4_ERROR_INODE(inode,
- "first_extent(path[%d].p_hdr) != ex",
- depth);
- return -EIO;
- }
- while (--depth >= 0) {
- ix = path[depth].p_idx;
- if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
- EXT4_ERROR_INODE(inode,
- "ix != EXT_FIRST_INDEX *logical %d!",
- *logical);
- return -EIO;
- }
- }
- *logical = le32_to_cpu(ex->ee_block);
- *phys = ext4_ext_pblock(ex);
- return 0;
- }
- if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
- EXT4_ERROR_INODE(inode,
- "logical %d < ee_block %d + ee_len %d!",
- *logical, le32_to_cpu(ex->ee_block), ee_len);
- return -EIO;
- }
- if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
- /* next allocated block in this leaf */
- ex++;
- *logical = le32_to_cpu(ex->ee_block);
- *phys = ext4_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))
- goto got_index;
- }
- /* we've gone up to the root and found no index to the right */
- return 0;
- got_index:
- /* we've found index to the right, let's
- * follow it and find the closest allocated
- * block to the right */
- ix++;
- block = ext4_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);
- /* subtract from p_depth to get proper eh_depth */
- if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
- put_bh(bh);
- return -EIO;
- }
- ix = EXT_FIRST_INDEX(eh);
- block = ext4_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(inode, eh, path->p_depth - depth)) {
- put_bh(bh);
- return -EIO;
- }
- ex = EXT_FIRST_EXTENT(eh);
- *logical = le32_to_cpu(ex->ee_block);
- *phys = ext4_ext_pblock(ex);
- put_bh(bh);
- return 0;
- }
- /*
- * ext4_ext_next_allocated_block:
- * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
- * 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_BLOCKS;
- 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_BLOCKS;
- }
- /*
- * ext4_ext_next_leaf_block:
- * returns first allocated block from next leaf or EXT_MAX_BLOCKS
- */
- static ext4_lblk_t ext4_ext_next_leaf_block(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_BLOCKS;
- /* 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_BLOCKS;
- }
- /*
- * 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;
- if (unlikely(ex == NULL || eh == NULL)) {
- EXT4_ERROR_INODE(inode,
- "ex %p == NULL or eh %p == NULL", ex, eh);
- return -EIO;
- }
- 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;
- }
- 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 (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_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.
- */
- static int ext4_ext_try_to_merge_right(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(inode, "eh->eh_entries = 0!");
- }
- return merge_done;
- }
- /*
- * This function tries to merge the @ex extent to neighbours in the tree.
- * return 1 if merge left else 0.
- */
- static 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;
- int merge_done = 0;
- int ret = 0;
- depth = ext_depth(inode);
- BUG_ON(path[depth].p_hdr == NULL);
- eh = path[depth].p_hdr;
- if (ex > EXT_FIRST_EXTENT(eh))
- merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
- if (!merge_done)
- ret = ext4_ext_try_to_merge_right(inode, path, ex);
- return ret;
- }
- /*
- * 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.
- */
- static 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_BLOCKS)
- goto out;
- }
- /* check for wrap through zero on extent logical start block*/
- if (b1 + len1 < b1) {
- len1 = EXT_MAX_BLOCKS - 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, int flag)
- {
- 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;
- int flags = 0;
- if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
- EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
- return -EIO;
- }
- depth = ext_depth(inode);
- ex = path[depth].p_ext;
- if (unlikely(path[depth].p_hdr == NULL)) {
- EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
- return -EIO;
- }
- /* try to insert block into found extent and return */
- if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)
- && ext4_can_extents_be_merged(inode, ex, newext)) {
- ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n",
- ext4_ext_is_uninitialized(newext),
- ext4_ext_get_actual_len(newext),
- le32_to_cpu(ex->ee_block),
- ext4_ext_is_uninitialized(ex),
- ext4_ext_get_actual_len(ex),
- ext4_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;
- }
- 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 = EXT_MAX_BLOCKS;
- if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
- next = ext4_ext_next_leaf_block(path);
- if (next != EXT_MAX_BLOCKS) {
- 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 isn't full(%d)\n",
- le16_to_cpu(eh->eh_entries));
- path = npath;
- goto has_space;
- }
- 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.
- */
- if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT)
- flags = EXT4_MB_USE_ROOT_BLOCKS;
- err = ext4_ext_create_new_leaf(handle, inode, flags, 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]%d\n",
- le32_to_cpu(newext->ee_block),
- ext4_ext_pblock(newext),
- ext4_ext_is_uninitialized(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]%d after: nearest 0x%p, "
- "move %d from 0x%p to 0x%p\n",
- le32_to_cpu(newext->ee_block),
- ext4_ext_pblock(newext),
- ext4_ext_is_uninitialized(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]%d before: nearest 0x%p, "
- "move %d from 0x%p to 0x%p\n",
- le32_to_cpu(newext->ee_block),
- ext4_ext_pblock(newext),
- ext4_ext_is_uninitialized(newext),
- ext4_ext_get_actual_len(newext),
- nearex, len, nearex, nearex + 1);
- 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, ext4_ext_pblock(newext));
- nearex->ee_len = newext->ee_len;
- merge:
- /* try to merge extents to the right */
- if (!(flag & EXT4_GET_BLOCKS_PRE_IO))
- 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_invalidate_cache(inode);
- return err;
- }
- static int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
- ext4_lblk_t num, ext_prepare_callback func,
- void *cbdata)
- {
- struct ext4_ext_path *path = NULL;
- struct ext4_ext_cache cbex;
- struct ext4_extent *ex;
- ext4_lblk_t next, start = 0, end = 0;
- ext4_lblk_t last = block + num;
- int depth, exists, err = 0;
- BUG_ON(func == NULL);
- BUG_ON(inode == NULL);
- while (block < last && block != EXT_MAX_BLOCKS) {
- num = last - block;
- /* find extent for this block */
- down_read(&EXT4_I(inode)->i_data_sem);
- path = ext4_ext_find_extent(inode, block, path);
- up_read(&EXT4_I(inode)->i_data_sem);
- if (IS_ERR(path)) {
- err = PTR_ERR(path);
- path = NULL;
- break;
- }
- depth = ext_depth(inode);
- if (unlikely(path[depth].p_hdr == NULL)) {
- EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
- err = -EIO;
- break;
- }
- ex = path[depth].p_ext;
- next = ext4_ext_next_allocated_block(path);
- exists = 0;
- if (!ex) {
- /* there is no extent yet, so try to allocate
- * all requested space */
- start = block;
- end = block + num;
- } else if (le32_to_cpu(ex->ee_block) > block) {
- /* need to allocate space before found extent */
- start = block;
- end = le32_to_cpu(ex->ee_block);
- if (block + num < end)
- end = block + num;
- } else if (block >= le32_to_cpu(ex->ee_block)
- + ext4_ext_get_actual_len(ex)) {
- /* need to allocate space after found extent */
- start = block;
- end = block + num;
- if (end >= next)
- end = next;
- } else if (block >= le32_to_cpu(ex->ee_block)) {
- /*
- * some part of requested space is covered
- * by found extent
- */
- start = block;
- end = le32_to_cpu(ex->ee_block)
- + ext4_ext_get_actual_len(ex);
- if (block + num < end)
- end = block + num;
- exists = 1;
- } else {
- BUG();
- }
- BUG_ON(end <= start);
- if (!exists) {
- cbex.ec_block = start;
- cbex.ec_len = end - start;
- cbex.ec_start = 0;
- } else {
- cbex.ec_block = le32_to_cpu(ex->ee_block);
- cbex.ec_len = ext4_ext_get_actual_len(ex);
- cbex.ec_start = ext4_ext_pblock(ex);
- }
- if (unlikely(cbex.ec_len == 0)) {
- EXT4_ERROR_INODE(inode, "cbex.ec_len == 0");
- err = -EIO;
- break;
- }
- err = func(inode, next, &cbex, ex, cbdata);
- ext4_ext_drop_refs(path);
- if (err < 0)
- break;
- if (err == EXT_REPEAT)
- continue;
- else if (err == EXT_BREAK) {
- err = 0;
- break;
- }
- if (ext_depth(inode) != depth) {
- /* depth was changed. we have to realloc path */
- kfree(path);
- path = NULL;
- }
- block = cbex.ec_block + cbex.ec_len;
- }
- if (path) {
- ext4_ext_drop_refs(path);
- kfree(path);
- }
- 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);
- 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 bl