blob: 10bfb466e0687eb4c99dd3c5fc1e787c07d68efc [file] [log] [blame]
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* alloc.c
*
* Extent allocs and frees
*
* Copyright (C) 2002, 2004 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* 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
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/swap.h>
#define MLOG_MASK_PREFIX ML_DISK_ALLOC
#include <cluster/masklog.h>
#include "ocfs2.h"
#include "alloc.h"
#include "aops.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "inode.h"
#include "journal.h"
#include "localalloc.h"
#include "suballoc.h"
#include "sysfile.h"
#include "file.h"
#include "super.h"
#include "uptodate.h"
#include "buffer_head_io.h"
static void ocfs2_free_truncate_context(struct ocfs2_truncate_context *tc);
static int ocfs2_cache_extent_block_free(struct ocfs2_cached_dealloc_ctxt *ctxt,
struct ocfs2_extent_block *eb);
/*
* Structures which describe a path through a btree, and functions to
* manipulate them.
*
* The idea here is to be as generic as possible with the tree
* manipulation code.
*/
struct ocfs2_path_item {
struct buffer_head *bh;
struct ocfs2_extent_list *el;
};
#define OCFS2_MAX_PATH_DEPTH 5
struct ocfs2_path {
int p_tree_depth;
struct ocfs2_path_item p_node[OCFS2_MAX_PATH_DEPTH];
};
#define path_root_bh(_path) ((_path)->p_node[0].bh)
#define path_root_el(_path) ((_path)->p_node[0].el)
#define path_leaf_bh(_path) ((_path)->p_node[(_path)->p_tree_depth].bh)
#define path_leaf_el(_path) ((_path)->p_node[(_path)->p_tree_depth].el)
#define path_num_items(_path) ((_path)->p_tree_depth + 1)
/*
* Reset the actual path elements so that we can re-use the structure
* to build another path. Generally, this involves freeing the buffer
* heads.
*/
static void ocfs2_reinit_path(struct ocfs2_path *path, int keep_root)
{
int i, start = 0, depth = 0;
struct ocfs2_path_item *node;
if (keep_root)
start = 1;
for(i = start; i < path_num_items(path); i++) {
node = &path->p_node[i];
brelse(node->bh);
node->bh = NULL;
node->el = NULL;
}
/*
* Tree depth may change during truncate, or insert. If we're
* keeping the root extent list, then make sure that our path
* structure reflects the proper depth.
*/
if (keep_root)
depth = le16_to_cpu(path_root_el(path)->l_tree_depth);
path->p_tree_depth = depth;
}
static void ocfs2_free_path(struct ocfs2_path *path)
{
if (path) {
ocfs2_reinit_path(path, 0);
kfree(path);
}
}
/*
* All the elements of src into dest. After this call, src could be freed
* without affecting dest.
*
* Both paths should have the same root. Any non-root elements of dest
* will be freed.
*/
static void ocfs2_cp_path(struct ocfs2_path *dest, struct ocfs2_path *src)
{
int i;
BUG_ON(path_root_bh(dest) != path_root_bh(src));
BUG_ON(path_root_el(dest) != path_root_el(src));
ocfs2_reinit_path(dest, 1);
for(i = 1; i < OCFS2_MAX_PATH_DEPTH; i++) {
dest->p_node[i].bh = src->p_node[i].bh;
dest->p_node[i].el = src->p_node[i].el;
if (dest->p_node[i].bh)
get_bh(dest->p_node[i].bh);
}
}
/*
* Make the *dest path the same as src and re-initialize src path to
* have a root only.
*/
static void ocfs2_mv_path(struct ocfs2_path *dest, struct ocfs2_path *src)
{
int i;
BUG_ON(path_root_bh(dest) != path_root_bh(src));
for(i = 1; i < OCFS2_MAX_PATH_DEPTH; i++) {
brelse(dest->p_node[i].bh);
dest->p_node[i].bh = src->p_node[i].bh;
dest->p_node[i].el = src->p_node[i].el;
src->p_node[i].bh = NULL;
src->p_node[i].el = NULL;
}
}
/*
* Insert an extent block at given index.
*
* This will not take an additional reference on eb_bh.
*/
static inline void ocfs2_path_insert_eb(struct ocfs2_path *path, int index,
struct buffer_head *eb_bh)
{
struct ocfs2_extent_block *eb = (struct ocfs2_extent_block *)eb_bh->b_data;
/*
* Right now, no root bh is an extent block, so this helps
* catch code errors with dinode trees. The assertion can be
* safely removed if we ever need to insert extent block
* structures at the root.
*/
BUG_ON(index == 0);
path->p_node[index].bh = eb_bh;
path->p_node[index].el = &eb->h_list;
}
static struct ocfs2_path *ocfs2_new_path(struct buffer_head *root_bh,
struct ocfs2_extent_list *root_el)
{
struct ocfs2_path *path;
BUG_ON(le16_to_cpu(root_el->l_tree_depth) >= OCFS2_MAX_PATH_DEPTH);
path = kzalloc(sizeof(*path), GFP_NOFS);
if (path) {
path->p_tree_depth = le16_to_cpu(root_el->l_tree_depth);
get_bh(root_bh);
path_root_bh(path) = root_bh;
path_root_el(path) = root_el;
}
return path;
}
/*
* Allocate and initialize a new path based on a disk inode tree.
*/
static struct ocfs2_path *ocfs2_new_inode_path(struct buffer_head *di_bh)
{
struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
struct ocfs2_extent_list *el = &di->id2.i_list;
return ocfs2_new_path(di_bh, el);
}
/*
* Convenience function to journal all components in a path.
*/
static int ocfs2_journal_access_path(struct inode *inode, handle_t *handle,
struct ocfs2_path *path)
{
int i, ret = 0;
if (!path)
goto out;
for(i = 0; i < path_num_items(path); i++) {
ret = ocfs2_journal_access(handle, inode, path->p_node[i].bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
}
out:
return ret;
}
/*
* Return the index of the extent record which contains cluster #v_cluster.
* -1 is returned if it was not found.
*
* Should work fine on interior and exterior nodes.
*/
int ocfs2_search_extent_list(struct ocfs2_extent_list *el, u32 v_cluster)
{
int ret = -1;
int i;
struct ocfs2_extent_rec *rec;
u32 rec_end, rec_start, clusters;
for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
rec = &el->l_recs[i];
rec_start = le32_to_cpu(rec->e_cpos);
clusters = ocfs2_rec_clusters(el, rec);
rec_end = rec_start + clusters;
if (v_cluster >= rec_start && v_cluster < rec_end) {
ret = i;
break;
}
}
return ret;
}
enum ocfs2_contig_type {
CONTIG_NONE = 0,
CONTIG_LEFT,
CONTIG_RIGHT,
CONTIG_LEFTRIGHT,
};
/*
* NOTE: ocfs2_block_extent_contig(), ocfs2_extents_adjacent() and
* ocfs2_extent_contig only work properly against leaf nodes!
*/
static int ocfs2_block_extent_contig(struct super_block *sb,
struct ocfs2_extent_rec *ext,
u64 blkno)
{
u64 blk_end = le64_to_cpu(ext->e_blkno);
blk_end += ocfs2_clusters_to_blocks(sb,
le16_to_cpu(ext->e_leaf_clusters));
return blkno == blk_end;
}
static int ocfs2_extents_adjacent(struct ocfs2_extent_rec *left,
struct ocfs2_extent_rec *right)
{
u32 left_range;
left_range = le32_to_cpu(left->e_cpos) +
le16_to_cpu(left->e_leaf_clusters);
return (left_range == le32_to_cpu(right->e_cpos));
}
static enum ocfs2_contig_type
ocfs2_extent_contig(struct inode *inode,
struct ocfs2_extent_rec *ext,
struct ocfs2_extent_rec *insert_rec)
{
u64 blkno = le64_to_cpu(insert_rec->e_blkno);
/*
* Refuse to coalesce extent records with different flag
* fields - we don't want to mix unwritten extents with user
* data.
*/
if (ext->e_flags != insert_rec->e_flags)
return CONTIG_NONE;
if (ocfs2_extents_adjacent(ext, insert_rec) &&
ocfs2_block_extent_contig(inode->i_sb, ext, blkno))
return CONTIG_RIGHT;
blkno = le64_to_cpu(ext->e_blkno);
if (ocfs2_extents_adjacent(insert_rec, ext) &&
ocfs2_block_extent_contig(inode->i_sb, insert_rec, blkno))
return CONTIG_LEFT;
return CONTIG_NONE;
}
/*
* NOTE: We can have pretty much any combination of contiguousness and
* appending.
*
* The usefulness of APPEND_TAIL is more in that it lets us know that
* we'll have to update the path to that leaf.
*/
enum ocfs2_append_type {
APPEND_NONE = 0,
APPEND_TAIL,
};
enum ocfs2_split_type {
SPLIT_NONE = 0,
SPLIT_LEFT,
SPLIT_RIGHT,
};
struct ocfs2_insert_type {
enum ocfs2_split_type ins_split;
enum ocfs2_append_type ins_appending;
enum ocfs2_contig_type ins_contig;
int ins_contig_index;
int ins_tree_depth;
};
struct ocfs2_merge_ctxt {
enum ocfs2_contig_type c_contig_type;
int c_has_empty_extent;
int c_split_covers_rec;
};
/*
* How many free extents have we got before we need more meta data?
*/
int ocfs2_num_free_extents(struct ocfs2_super *osb,
struct inode *inode,
struct ocfs2_dinode *fe)
{
int retval;
struct ocfs2_extent_list *el;
struct ocfs2_extent_block *eb;
struct buffer_head *eb_bh = NULL;
mlog_entry_void();
if (!OCFS2_IS_VALID_DINODE(fe)) {
OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, fe);
retval = -EIO;
goto bail;
}
if (fe->i_last_eb_blk) {
retval = ocfs2_read_block(osb, le64_to_cpu(fe->i_last_eb_blk),
&eb_bh, OCFS2_BH_CACHED, inode);
if (retval < 0) {
mlog_errno(retval);
goto bail;
}
eb = (struct ocfs2_extent_block *) eb_bh->b_data;
el = &eb->h_list;
} else
el = &fe->id2.i_list;
BUG_ON(el->l_tree_depth != 0);
retval = le16_to_cpu(el->l_count) - le16_to_cpu(el->l_next_free_rec);
bail:
if (eb_bh)
brelse(eb_bh);
mlog_exit(retval);
return retval;
}
/* expects array to already be allocated
*
* sets h_signature, h_blkno, h_suballoc_bit, h_suballoc_slot, and
* l_count for you
*/
static int ocfs2_create_new_meta_bhs(struct ocfs2_super *osb,
handle_t *handle,
struct inode *inode,
int wanted,
struct ocfs2_alloc_context *meta_ac,
struct buffer_head *bhs[])
{
int count, status, i;
u16 suballoc_bit_start;
u32 num_got;
u64 first_blkno;
struct ocfs2_extent_block *eb;
mlog_entry_void();
count = 0;
while (count < wanted) {
status = ocfs2_claim_metadata(osb,
handle,
meta_ac,
wanted - count,
&suballoc_bit_start,
&num_got,
&first_blkno);
if (status < 0) {
mlog_errno(status);
goto bail;
}
for(i = count; i < (num_got + count); i++) {
bhs[i] = sb_getblk(osb->sb, first_blkno);
if (bhs[i] == NULL) {
status = -EIO;
mlog_errno(status);
goto bail;
}
ocfs2_set_new_buffer_uptodate(inode, bhs[i]);
status = ocfs2_journal_access(handle, inode, bhs[i],
OCFS2_JOURNAL_ACCESS_CREATE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
memset(bhs[i]->b_data, 0, osb->sb->s_blocksize);
eb = (struct ocfs2_extent_block *) bhs[i]->b_data;
/* Ok, setup the minimal stuff here. */
strcpy(eb->h_signature, OCFS2_EXTENT_BLOCK_SIGNATURE);
eb->h_blkno = cpu_to_le64(first_blkno);
eb->h_fs_generation = cpu_to_le32(osb->fs_generation);
eb->h_suballoc_slot = cpu_to_le16(osb->slot_num);
eb->h_suballoc_bit = cpu_to_le16(suballoc_bit_start);
eb->h_list.l_count =
cpu_to_le16(ocfs2_extent_recs_per_eb(osb->sb));
suballoc_bit_start++;
first_blkno++;
/* We'll also be dirtied by the caller, so
* this isn't absolutely necessary. */
status = ocfs2_journal_dirty(handle, bhs[i]);
if (status < 0) {
mlog_errno(status);
goto bail;
}
}
count += num_got;
}
status = 0;
bail:
if (status < 0) {
for(i = 0; i < wanted; i++) {
if (bhs[i])
brelse(bhs[i]);
bhs[i] = NULL;
}
}
mlog_exit(status);
return status;
}
/*
* Helper function for ocfs2_add_branch() and ocfs2_shift_tree_depth().
*
* Returns the sum of the rightmost extent rec logical offset and
* cluster count.
*
* ocfs2_add_branch() uses this to determine what logical cluster
* value should be populated into the leftmost new branch records.
*
* ocfs2_shift_tree_depth() uses this to determine the # clusters
* value for the new topmost tree record.
*/
static inline u32 ocfs2_sum_rightmost_rec(struct ocfs2_extent_list *el)
{
int i;
i = le16_to_cpu(el->l_next_free_rec) - 1;
return le32_to_cpu(el->l_recs[i].e_cpos) +
ocfs2_rec_clusters(el, &el->l_recs[i]);
}
/*
* Add an entire tree branch to our inode. eb_bh is the extent block
* to start at, if we don't want to start the branch at the dinode
* structure.
*
* last_eb_bh is required as we have to update it's next_leaf pointer
* for the new last extent block.
*
* the new branch will be 'empty' in the sense that every block will
* contain a single record with cluster count == 0.
*/
static int ocfs2_add_branch(struct ocfs2_super *osb,
handle_t *handle,
struct inode *inode,
struct buffer_head *fe_bh,
struct buffer_head *eb_bh,
struct buffer_head **last_eb_bh,
struct ocfs2_alloc_context *meta_ac)
{
int status, new_blocks, i;
u64 next_blkno, new_last_eb_blk;
struct buffer_head *bh;
struct buffer_head **new_eb_bhs = NULL;
struct ocfs2_dinode *fe;
struct ocfs2_extent_block *eb;
struct ocfs2_extent_list *eb_el;
struct ocfs2_extent_list *el;
u32 new_cpos;
mlog_entry_void();
BUG_ON(!last_eb_bh || !*last_eb_bh);
fe = (struct ocfs2_dinode *) fe_bh->b_data;
if (eb_bh) {
eb = (struct ocfs2_extent_block *) eb_bh->b_data;
el = &eb->h_list;
} else
el = &fe->id2.i_list;
/* we never add a branch to a leaf. */
BUG_ON(!el->l_tree_depth);
new_blocks = le16_to_cpu(el->l_tree_depth);
/* allocate the number of new eb blocks we need */
new_eb_bhs = kcalloc(new_blocks, sizeof(struct buffer_head *),
GFP_KERNEL);
if (!new_eb_bhs) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
status = ocfs2_create_new_meta_bhs(osb, handle, inode, new_blocks,
meta_ac, new_eb_bhs);
if (status < 0) {
mlog_errno(status);
goto bail;
}
eb = (struct ocfs2_extent_block *)(*last_eb_bh)->b_data;
new_cpos = ocfs2_sum_rightmost_rec(&eb->h_list);
/* Note: new_eb_bhs[new_blocks - 1] is the guy which will be
* linked with the rest of the tree.
* conversly, new_eb_bhs[0] is the new bottommost leaf.
*
* when we leave the loop, new_last_eb_blk will point to the
* newest leaf, and next_blkno will point to the topmost extent
* block. */
next_blkno = new_last_eb_blk = 0;
for(i = 0; i < new_blocks; i++) {
bh = new_eb_bhs[i];
eb = (struct ocfs2_extent_block *) bh->b_data;
if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
status = -EIO;
goto bail;
}
eb_el = &eb->h_list;
status = ocfs2_journal_access(handle, inode, bh,
OCFS2_JOURNAL_ACCESS_CREATE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
eb->h_next_leaf_blk = 0;
eb_el->l_tree_depth = cpu_to_le16(i);
eb_el->l_next_free_rec = cpu_to_le16(1);
/*
* This actually counts as an empty extent as
* c_clusters == 0
*/
eb_el->l_recs[0].e_cpos = cpu_to_le32(new_cpos);
eb_el->l_recs[0].e_blkno = cpu_to_le64(next_blkno);
/*
* eb_el isn't always an interior node, but even leaf
* nodes want a zero'd flags and reserved field so
* this gets the whole 32 bits regardless of use.
*/
eb_el->l_recs[0].e_int_clusters = cpu_to_le32(0);
if (!eb_el->l_tree_depth)
new_last_eb_blk = le64_to_cpu(eb->h_blkno);
status = ocfs2_journal_dirty(handle, bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
next_blkno = le64_to_cpu(eb->h_blkno);
}
/* This is a bit hairy. We want to update up to three blocks
* here without leaving any of them in an inconsistent state
* in case of error. We don't have to worry about
* journal_dirty erroring as it won't unless we've aborted the
* handle (in which case we would never be here) so reserving
* the write with journal_access is all we need to do. */
status = ocfs2_journal_access(handle, inode, *last_eb_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
status = ocfs2_journal_access(handle, inode, fe_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
if (eb_bh) {
status = ocfs2_journal_access(handle, inode, eb_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
}
/* Link the new branch into the rest of the tree (el will
* either be on the fe, or the extent block passed in. */
i = le16_to_cpu(el->l_next_free_rec);
el->l_recs[i].e_blkno = cpu_to_le64(next_blkno);
el->l_recs[i].e_cpos = cpu_to_le32(new_cpos);
el->l_recs[i].e_int_clusters = 0;
le16_add_cpu(&el->l_next_free_rec, 1);
/* fe needs a new last extent block pointer, as does the
* next_leaf on the previously last-extent-block. */
fe->i_last_eb_blk = cpu_to_le64(new_last_eb_blk);
eb = (struct ocfs2_extent_block *) (*last_eb_bh)->b_data;
eb->h_next_leaf_blk = cpu_to_le64(new_last_eb_blk);
status = ocfs2_journal_dirty(handle, *last_eb_bh);
if (status < 0)
mlog_errno(status);
status = ocfs2_journal_dirty(handle, fe_bh);
if (status < 0)
mlog_errno(status);
if (eb_bh) {
status = ocfs2_journal_dirty(handle, eb_bh);
if (status < 0)
mlog_errno(status);
}
/*
* Some callers want to track the rightmost leaf so pass it
* back here.
*/
brelse(*last_eb_bh);
get_bh(new_eb_bhs[0]);
*last_eb_bh = new_eb_bhs[0];
status = 0;
bail:
if (new_eb_bhs) {
for (i = 0; i < new_blocks; i++)
if (new_eb_bhs[i])
brelse(new_eb_bhs[i]);
kfree(new_eb_bhs);
}
mlog_exit(status);
return status;
}
/*
* adds another level to the allocation tree.
* returns back the new extent block so you can add a branch to it
* after this call.
*/
static int ocfs2_shift_tree_depth(struct ocfs2_super *osb,
handle_t *handle,
struct inode *inode,
struct buffer_head *fe_bh,
struct ocfs2_alloc_context *meta_ac,
struct buffer_head **ret_new_eb_bh)
{
int status, i;
u32 new_clusters;
struct buffer_head *new_eb_bh = NULL;
struct ocfs2_dinode *fe;
struct ocfs2_extent_block *eb;
struct ocfs2_extent_list *fe_el;
struct ocfs2_extent_list *eb_el;
mlog_entry_void();
status = ocfs2_create_new_meta_bhs(osb, handle, inode, 1, meta_ac,
&new_eb_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
eb = (struct ocfs2_extent_block *) new_eb_bh->b_data;
if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
status = -EIO;
goto bail;
}
eb_el = &eb->h_list;
fe = (struct ocfs2_dinode *) fe_bh->b_data;
fe_el = &fe->id2.i_list;
status = ocfs2_journal_access(handle, inode, new_eb_bh,
OCFS2_JOURNAL_ACCESS_CREATE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
/* copy the fe data into the new extent block */
eb_el->l_tree_depth = fe_el->l_tree_depth;
eb_el->l_next_free_rec = fe_el->l_next_free_rec;
for(i = 0; i < le16_to_cpu(fe_el->l_next_free_rec); i++)
eb_el->l_recs[i] = fe_el->l_recs[i];
status = ocfs2_journal_dirty(handle, new_eb_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
status = ocfs2_journal_access(handle, inode, fe_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (status < 0) {
mlog_errno(status);
goto bail;
}
new_clusters = ocfs2_sum_rightmost_rec(eb_el);
/* update fe now */
le16_add_cpu(&fe_el->l_tree_depth, 1);
fe_el->l_recs[0].e_cpos = 0;
fe_el->l_recs[0].e_blkno = eb->h_blkno;
fe_el->l_recs[0].e_int_clusters = cpu_to_le32(new_clusters);
for(i = 1; i < le16_to_cpu(fe_el->l_next_free_rec); i++)
memset(&fe_el->l_recs[i], 0, sizeof(struct ocfs2_extent_rec));
fe_el->l_next_free_rec = cpu_to_le16(1);
/* If this is our 1st tree depth shift, then last_eb_blk
* becomes the allocated extent block */
if (fe_el->l_tree_depth == cpu_to_le16(1))
fe->i_last_eb_blk = eb->h_blkno;
status = ocfs2_journal_dirty(handle, fe_bh);
if (status < 0) {
mlog_errno(status);
goto bail;
}
*ret_new_eb_bh = new_eb_bh;
new_eb_bh = NULL;
status = 0;
bail:
if (new_eb_bh)
brelse(new_eb_bh);
mlog_exit(status);
return status;
}
/*
* Should only be called when there is no space left in any of the
* leaf nodes. What we want to do is find the lowest tree depth
* non-leaf extent block with room for new records. There are three
* valid results of this search:
*
* 1) a lowest extent block is found, then we pass it back in
* *lowest_eb_bh and return '0'
*
* 2) the search fails to find anything, but the dinode has room. We
* pass NULL back in *lowest_eb_bh, but still return '0'
*
* 3) the search fails to find anything AND the dinode is full, in
* which case we return > 0
*
* return status < 0 indicates an error.
*/
static int ocfs2_find_branch_target(struct ocfs2_super *osb,
struct inode *inode,
struct buffer_head *fe_bh,
struct buffer_head **target_bh)
{
int status = 0, i;
u64 blkno;
struct ocfs2_dinode *fe;
struct ocfs2_extent_block *eb;
struct ocfs2_extent_list *el;
struct buffer_head *bh = NULL;
struct buffer_head *lowest_bh = NULL;
mlog_entry_void();
*target_bh = NULL;
fe = (struct ocfs2_dinode *) fe_bh->b_data;
el = &fe->id2.i_list;
while(le16_to_cpu(el->l_tree_depth) > 1) {
if (le16_to_cpu(el->l_next_free_rec) == 0) {
ocfs2_error(inode->i_sb, "Dinode %llu has empty "
"extent list (next_free_rec == 0)",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
status = -EIO;
goto bail;
}
i = le16_to_cpu(el->l_next_free_rec) - 1;
blkno = le64_to_cpu(el->l_recs[i].e_blkno);
if (!blkno) {
ocfs2_error(inode->i_sb, "Dinode %llu has extent "
"list where extent # %d has no physical "
"block start",
(unsigned long long)OCFS2_I(inode)->ip_blkno, i);
status = -EIO;
goto bail;
}
if (bh) {
brelse(bh);
bh = NULL;
}
status = ocfs2_read_block(osb, blkno, &bh, OCFS2_BH_CACHED,
inode);
if (status < 0) {
mlog_errno(status);
goto bail;
}
eb = (struct ocfs2_extent_block *) bh->b_data;
if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
status = -EIO;
goto bail;
}
el = &eb->h_list;
if (le16_to_cpu(el->l_next_free_rec) <
le16_to_cpu(el->l_count)) {
if (lowest_bh)
brelse(lowest_bh);
lowest_bh = bh;
get_bh(lowest_bh);
}
}
/* If we didn't find one and the fe doesn't have any room,
* then return '1' */
if (!lowest_bh
&& (fe->id2.i_list.l_next_free_rec == fe->id2.i_list.l_count))
status = 1;
*target_bh = lowest_bh;
bail:
if (bh)
brelse(bh);
mlog_exit(status);
return status;
}
/*
* Grow a b-tree so that it has more records.
*
* We might shift the tree depth in which case existing paths should
* be considered invalid.
*
* Tree depth after the grow is returned via *final_depth.
*
* *last_eb_bh will be updated by ocfs2_add_branch().
*/
static int ocfs2_grow_tree(struct inode *inode, handle_t *handle,
struct buffer_head *di_bh, int *final_depth,
struct buffer_head **last_eb_bh,
struct ocfs2_alloc_context *meta_ac)
{
int ret, shift;
struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
int depth = le16_to_cpu(di->id2.i_list.l_tree_depth);
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
struct buffer_head *bh = NULL;
BUG_ON(meta_ac == NULL);
shift = ocfs2_find_branch_target(osb, inode, di_bh, &bh);
if (shift < 0) {
ret = shift;
mlog_errno(ret);
goto out;
}
/* We traveled all the way to the bottom of the allocation tree
* and didn't find room for any more extents - we need to add
* another tree level */
if (shift) {
BUG_ON(bh);
mlog(0, "need to shift tree depth (current = %d)\n", depth);
/* ocfs2_shift_tree_depth will return us a buffer with
* the new extent block (so we can pass that to
* ocfs2_add_branch). */
ret = ocfs2_shift_tree_depth(osb, handle, inode, di_bh,
meta_ac, &bh);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
depth++;
if (depth == 1) {
/*
* Special case: we have room now if we shifted from
* tree_depth 0, so no more work needs to be done.
*
* We won't be calling add_branch, so pass
* back *last_eb_bh as the new leaf. At depth
* zero, it should always be null so there's
* no reason to brelse.
*/
BUG_ON(*last_eb_bh);
get_bh(bh);
*last_eb_bh = bh;
goto out;
}
}
/* call ocfs2_add_branch to add the final part of the tree with
* the new data. */
mlog(0, "add branch. bh = %p\n", bh);
ret = ocfs2_add_branch(osb, handle, inode, di_bh, bh, last_eb_bh,
meta_ac);
if (ret < 0) {
mlog_errno(ret);
goto out;
}
out:
if (final_depth)
*final_depth = depth;
brelse(bh);
return ret;
}
/*
* This is only valid for leaf nodes, which are the only ones that can
* have empty extents anyway.
*/
static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec)
{
return !rec->e_leaf_clusters;
}
/*
* This function will discard the rightmost extent record.
*/
static void ocfs2_shift_records_right(struct ocfs2_extent_list *el)
{
int next_free = le16_to_cpu(el->l_next_free_rec);
int count = le16_to_cpu(el->l_count);
unsigned int num_bytes;
BUG_ON(!next_free);
/* This will cause us to go off the end of our extent list. */
BUG_ON(next_free >= count);
num_bytes = sizeof(struct ocfs2_extent_rec) * next_free;
memmove(&el->l_recs[1], &el->l_recs[0], num_bytes);
}
static void ocfs2_rotate_leaf(struct ocfs2_extent_list *el,
struct ocfs2_extent_rec *insert_rec)
{
int i, insert_index, next_free, has_empty, num_bytes;
u32 insert_cpos = le32_to_cpu(insert_rec->e_cpos);
struct ocfs2_extent_rec *rec;
next_free = le16_to_cpu(el->l_next_free_rec);
has_empty = ocfs2_is_empty_extent(&el->l_recs[0]);
BUG_ON(!next_free);
/* The tree code before us didn't allow enough room in the leaf. */
BUG_ON(el->l_next_free_rec == el->l_count && !has_empty);
/*
* The easiest way to approach this is to just remove the
* empty extent and temporarily decrement next_free.
*/
if (has_empty) {
/*
* If next_free was 1 (only an empty extent), this
* loop won't execute, which is fine. We still want
* the decrement above to happen.
*/
for(i = 0; i < (next_free - 1); i++)
el->l_recs[i] = el->l_recs[i+1];
next_free--;
}
/*
* Figure out what the new record index should be.
*/
for(i = 0; i < next_free; i++) {
rec = &el->l_recs[i];
if (insert_cpos < le32_to_cpu(rec->e_cpos))
break;
}
insert_index = i;
mlog(0, "ins %u: index %d, has_empty %d, next_free %d, count %d\n",
insert_cpos, insert_index, has_empty, next_free, le16_to_cpu(el->l_count));
BUG_ON(insert_index < 0);
BUG_ON(insert_index >= le16_to_cpu(el->l_count));
BUG_ON(insert_index > next_free);
/*
* No need to memmove if we're just adding to the tail.
*/
if (insert_index != next_free) {
BUG_ON(next_free >= le16_to_cpu(el->l_count));
num_bytes = next_free - insert_index;
num_bytes *= sizeof(struct ocfs2_extent_rec);
memmove(&el->l_recs[insert_index + 1],
&el->l_recs[insert_index],
num_bytes);
}
/*
* Either we had an empty extent, and need to re-increment or
* there was no empty extent on a non full rightmost leaf node,
* in which case we still need to increment.
*/
next_free++;
el->l_next_free_rec = cpu_to_le16(next_free);
/*
* Make sure none of the math above just messed up our tree.
*/
BUG_ON(le16_to_cpu(el->l_next_free_rec) > le16_to_cpu(el->l_count));
el->l_recs[insert_index] = *insert_rec;
}
static void ocfs2_remove_empty_extent(struct ocfs2_extent_list *el)
{
int size, num_recs = le16_to_cpu(el->l_next_free_rec);
BUG_ON(num_recs == 0);
if (ocfs2_is_empty_extent(&el->l_recs[0])) {
num_recs--;
size = num_recs * sizeof(struct ocfs2_extent_rec);
memmove(&el->l_recs[0], &el->l_recs[1], size);
memset(&el->l_recs[num_recs], 0,
sizeof(struct ocfs2_extent_rec));
el->l_next_free_rec = cpu_to_le16(num_recs);
}
}
/*
* Create an empty extent record .
*
* l_next_free_rec may be updated.
*
* If an empty extent already exists do nothing.
*/
static void ocfs2_create_empty_extent(struct ocfs2_extent_list *el)
{
int next_free = le16_to_cpu(el->l_next_free_rec);
BUG_ON(le16_to_cpu(el->l_tree_depth) != 0);
if (next_free == 0)
goto set_and_inc;
if (ocfs2_is_empty_extent(&el->l_recs[0]))
return;
mlog_bug_on_msg(el->l_count == el->l_next_free_rec,
"Asked to create an empty extent in a full list:\n"
"count = %u, tree depth = %u",
le16_to_cpu(el->l_count),
le16_to_cpu(el->l_tree_depth));
ocfs2_shift_records_right(el);
set_and_inc:
le16_add_cpu(&el->l_next_free_rec, 1);
memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
}
/*
* For a rotation which involves two leaf nodes, the "root node" is
* the lowest level tree node which contains a path to both leafs. This
* resulting set of information can be used to form a complete "subtree"
*
* This function is passed two full paths from the dinode down to a
* pair of adjacent leaves. It's task is to figure out which path
* index contains the subtree root - this can be the root index itself
* in a worst-case rotation.
*
* The array index of the subtree root is passed back.
*/
static int ocfs2_find_subtree_root(struct inode *inode,
struct ocfs2_path *left,
struct ocfs2_path *right)
{
int i = 0;
/*
* Check that the caller passed in two paths from the same tree.
*/
BUG_ON(path_root_bh(left) != path_root_bh(right));
do {
i++;
/*
* The caller didn't pass two adjacent paths.
*/
mlog_bug_on_msg(i > left->p_tree_depth,
"Inode %lu, left depth %u, right depth %u\n"
"left leaf blk %llu, right leaf blk %llu\n",
inode->i_ino, left->p_tree_depth,
right->p_tree_depth,
(unsigned long long)path_leaf_bh(left)->b_blocknr,
(unsigned long long)path_leaf_bh(right)->b_blocknr);
} while (left->p_node[i].bh->b_blocknr ==
right->p_node[i].bh->b_blocknr);
return i - 1;
}
typedef void (path_insert_t)(void *, struct buffer_head *);
/*
* Traverse a btree path in search of cpos, starting at root_el.
*
* This code can be called with a cpos larger than the tree, in which
* case it will return the rightmost path.
*/
static int __ocfs2_find_path(struct inode *inode,
struct ocfs2_extent_list *root_el, u32 cpos,
path_insert_t *func, void *data)
{
int i, ret = 0;
u32 range;
u64 blkno;
struct buffer_head *bh = NULL;
struct ocfs2_extent_block *eb;
struct ocfs2_extent_list *el;
struct ocfs2_extent_rec *rec;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
el = root_el;
while (el->l_tree_depth) {
if (le16_to_cpu(el->l_next_free_rec) == 0) {
ocfs2_error(inode->i_sb,
"Inode %llu has empty extent list at "
"depth %u\n",
(unsigned long long)oi->ip_blkno,
le16_to_cpu(el->l_tree_depth));
ret = -EROFS;
goto out;
}
for(i = 0; i < le16_to_cpu(el->l_next_free_rec) - 1; i++) {
rec = &el->l_recs[i];
/*
* In the case that cpos is off the allocation
* tree, this should just wind up returning the
* rightmost record.
*/
range = le32_to_cpu(rec->e_cpos) +
ocfs2_rec_clusters(el, rec);
if (cpos >= le32_to_cpu(rec->e_cpos) && cpos < range)
break;
}
blkno = le64_to_cpu(el->l_recs[i].e_blkno);
if (blkno == 0) {
ocfs2_error(inode->i_sb,
"Inode %llu has bad blkno in extent list "
"at depth %u (index %d)\n",
(unsigned long long)oi->ip_blkno,
le16_to_cpu(el->l_tree_depth), i);
ret = -EROFS;
goto out;
}
brelse(bh);
bh = NULL;
ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), blkno,
&bh, OCFS2_BH_CACHED, inode);
if (ret) {
mlog_errno(ret);
goto out;
}
eb = (struct ocfs2_extent_block *) bh->b_data;
el = &eb->h_list;
if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
ret = -EIO;
goto out;
}
if (le16_to_cpu(el->l_next_free_rec) >
le16_to_cpu(el->l_count)) {
ocfs2_error(inode->i_sb,
"Inode %llu has bad count in extent list "
"at block %llu (next free=%u, count=%u)\n",
(unsigned long long)oi->ip_blkno,
(unsigned long long)bh->b_blocknr,
le16_to_cpu(el->l_next_free_rec),
le16_to_cpu(el->l_count));
ret = -EROFS;
goto out;
}
if (func)
func(data, bh);
}
out:
/*
* Catch any trailing bh that the loop didn't handle.
*/
brelse(bh);
return ret;
}
/*
* Given an initialized path (that is, it has a valid root extent
* list), this function will traverse the btree in search of the path
* which would contain cpos.
*
* The path traveled is recorded in the path structure.
*
* Note that this will not do any comparisons on leaf node extent
* records, so it will work fine in the case that we just added a tree
* branch.
*/
struct find_path_data {
int index;
struct ocfs2_path *path;
};
static void find_path_ins(void *data, struct buffer_head *bh)
{
struct find_path_data *fp = data;
get_bh(bh);
ocfs2_path_insert_eb(fp->path, fp->index, bh);
fp->index++;
}
static int ocfs2_find_path(struct inode *inode, struct ocfs2_path *path,
u32 cpos)
{
struct find_path_data data;
data.index = 1;
data.path = path;
return __ocfs2_find_path(inode, path_root_el(path), cpos,
find_path_ins, &data);
}
static void find_leaf_ins(void *data, struct buffer_head *bh)
{
struct ocfs2_extent_block *eb =(struct ocfs2_extent_block *)bh->b_data;
struct ocfs2_extent_list *el = &eb->h_list;
struct buffer_head **ret = data;
/* We want to retain only the leaf block. */
if (le16_to_cpu(el->l_tree_depth) == 0) {
get_bh(bh);
*ret = bh;
}
}
/*
* Find the leaf block in the tree which would contain cpos. No
* checking of the actual leaf is done.
*
* Some paths want to call this instead of allocating a path structure
* and calling ocfs2_find_path().
*
* This function doesn't handle non btree extent lists.
*/
int ocfs2_find_leaf(struct inode *inode, struct ocfs2_extent_list *root_el,
u32 cpos, struct buffer_head **leaf_bh)
{
int ret;
struct buffer_head *bh = NULL;
ret = __ocfs2_find_path(inode, root_el, cpos, find_leaf_ins, &bh);
if (ret) {
mlog_errno(ret);
goto out;
}
*leaf_bh = bh;
out:
return ret;
}
/*
* Adjust the adjacent records (left_rec, right_rec) involved in a rotation.
*
* Basically, we've moved stuff around at the bottom of the tree and
* we need to fix up the extent records above the changes to reflect
* the new changes.
*
* left_rec: the record on the left.
* left_child_el: is the child list pointed to by left_rec
* right_rec: the record to the right of left_rec
* right_child_el: is the child list pointed to by right_rec
*
* By definition, this only works on interior nodes.
*/
static void ocfs2_adjust_adjacent_records(struct ocfs2_extent_rec *left_rec,
struct ocfs2_extent_list *left_child_el,
struct ocfs2_extent_rec *right_rec,
struct ocfs2_extent_list *right_child_el)
{
u32 left_clusters, right_end;
/*
* Interior nodes never have holes. Their cpos is the cpos of
* the leftmost record in their child list. Their cluster
* count covers the full theoretical range of their child list
* - the range between their cpos and the cpos of the record
* immediately to their right.
*/
left_clusters = le32_to_cpu(right_child_el->l_recs[0].e_cpos);
if (ocfs2_is_empty_extent(&right_child_el->l_recs[0])) {
BUG_ON(le16_to_cpu(right_child_el->l_next_free_rec) <= 1);
left_clusters = le32_to_cpu(right_child_el->l_recs[1].e_cpos);
}
left_clusters -= le32_to_cpu(left_rec->e_cpos);
left_rec->e_int_clusters = cpu_to_le32(left_clusters);
/*
* Calculate the rightmost cluster count boundary before
* moving cpos - we will need to adjust clusters after
* updating e_cpos to keep the same highest cluster count.
*/
right_end = le32_to_cpu(right_rec->e_cpos);
right_end += le32_to_cpu(right_rec->e_int_clusters);
right_rec->e_cpos = left_rec->e_cpos;
le32_add_cpu(&right_rec->e_cpos, left_clusters);
right_end -= le32_to_cpu(right_rec->e_cpos);
right_rec->e_int_clusters = cpu_to_le32(right_end);
}
/*
* Adjust the adjacent root node records involved in a
* rotation. left_el_blkno is passed in as a key so that we can easily
* find it's index in the root list.
*/
static void ocfs2_adjust_root_records(struct ocfs2_extent_list *root_el,
struct ocfs2_extent_list *left_el,
struct ocfs2_extent_list *right_el,
u64 left_el_blkno)
{
int i;
BUG_ON(le16_to_cpu(root_el->l_tree_depth) <=
le16_to_cpu(left_el->l_tree_depth));
for(i = 0; i < le16_to_cpu(root_el->l_next_free_rec) - 1; i++) {
if (le64_to_cpu(root_el->l_recs[i].e_blkno) == left_el_blkno)
break;
}
/*
* The path walking code should have never returned a root and
* two paths which are not adjacent.
*/
BUG_ON(i >= (le16_to_cpu(root_el->l_next_free_rec) - 1));
ocfs2_adjust_adjacent_records(&root_el->l_recs[i], left_el,
&root_el->l_recs[i + 1], right_el);
}
/*
* We've changed a leaf block (in right_path) and need to reflect that
* change back up the subtree.
*
* This happens in multiple places:
* - When we've moved an extent record from the left path leaf to the right
* path leaf to make room for an empty extent in the left path leaf.
* - When our insert into the right path leaf is at the leftmost edge
* and requires an update of the path immediately to it's left. This
* can occur at the end of some types of rotation and appending inserts.
* - When we've adjusted the last extent record in the left path leaf and the
* 1st extent record in the right path leaf during cross extent block merge.
*/
static void ocfs2_complete_edge_insert(struct inode *inode, handle_t *handle,
struct ocfs2_path *left_path,
struct ocfs2_path *right_path,
int subtree_index)
{
int ret, i, idx;
struct ocfs2_extent_list *el, *left_el, *right_el;
struct ocfs2_extent_rec *left_rec, *right_rec;
struct buffer_head *root_bh = left_path->p_node[subtree_index].bh;
/*
* Update the counts and position values within all the
* interior nodes to reflect the leaf rotation we just did.
*
* The root node is handled below the loop.
*
* We begin the loop with right_el and left_el pointing to the
* leaf lists and work our way up.
*
* NOTE: within this loop, left_el and right_el always refer
* to the *child* lists.
*/
left_el = path_leaf_el(left_path);
right_el = path_leaf_el(right_path);
for(i = left_path->p_tree_depth - 1; i > subtree_index; i--) {
mlog(0, "Adjust records at index %u\n", i);
/*
* One nice property of knowing that all of these
* nodes are below the root is that we only deal with
* the leftmost right node record and the rightmost
* left node record.
*/
el = left_path->p_node[i].el;
idx = le16_to_cpu(left_el->l_next_free_rec) - 1;
left_rec = &el->l_recs[idx];
el = right_path->p_node[i].el;
right_rec = &el->l_recs[0];
ocfs2_adjust_adjacent_records(left_rec, left_el, right_rec,
right_el);
ret = ocfs2_journal_dirty(handle, left_path->p_node[i].bh);
if (ret)
mlog_errno(ret);
ret = ocfs2_journal_dirty(handle, right_path->p_node[i].bh);
if (ret)
mlog_errno(ret);
/*
* Setup our list pointers now so that the current
* parents become children in the next iteration.
*/
left_el = left_path->p_node[i].el;
right_el = right_path->p_node[i].el;
}
/*
* At the root node, adjust the two adjacent records which
* begin our path to the leaves.
*/
el = left_path->p_node[subtree_index].el;
left_el = left_path->p_node[subtree_index + 1].el;
right_el = right_path->p_node[subtree_index + 1].el;
ocfs2_adjust_root_records(el, left_el, right_el,
left_path->p_node[subtree_index + 1].bh->b_blocknr);
root_bh = left_path->p_node[subtree_index].bh;
ret = ocfs2_journal_dirty(handle, root_bh);
if (ret)
mlog_errno(ret);
}
static int ocfs2_rotate_subtree_right(struct inode *inode,
handle_t *handle,
struct ocfs2_path *left_path,
struct ocfs2_path *right_path,
int subtree_index)
{
int ret, i;
struct buffer_head *right_leaf_bh;
struct buffer_head *left_leaf_bh = NULL;
struct buffer_head *root_bh;
struct ocfs2_extent_list *right_el, *left_el;
struct ocfs2_extent_rec move_rec;
left_leaf_bh = path_leaf_bh(left_path);
left_el = path_leaf_el(left_path);
if (left_el->l_next_free_rec != left_el->l_count) {
ocfs2_error(inode->i_sb,
"Inode %llu has non-full interior leaf node %llu"
"(next free = %u)",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(unsigned long long)left_leaf_bh->b_blocknr,
le16_to_cpu(left_el->l_next_free_rec));
return -EROFS;
}
/*
* This extent block may already have an empty record, so we
* return early if so.
*/
if (ocfs2_is_empty_extent(&left_el->l_recs[0]))
return 0;
root_bh = left_path->p_node[subtree_index].bh;
BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
ret = ocfs2_journal_access(handle, inode, root_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
for(i = subtree_index + 1; i < path_num_items(right_path); i++) {
ret = ocfs2_journal_access(handle, inode,
right_path->p_node[i].bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_journal_access(handle, inode,
left_path->p_node[i].bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
}
right_leaf_bh = path_leaf_bh(right_path);
right_el = path_leaf_el(right_path);
/* This is a code error, not a disk corruption. */
mlog_bug_on_msg(!right_el->l_next_free_rec, "Inode %llu: Rotate fails "
"because rightmost leaf block %llu is empty\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(unsigned long long)right_leaf_bh->b_blocknr);
ocfs2_create_empty_extent(right_el);
ret = ocfs2_journal_dirty(handle, right_leaf_bh);
if (ret) {
mlog_errno(ret);
goto out;
}
/* Do the copy now. */
i = le16_to_cpu(left_el->l_next_free_rec) - 1;
move_rec = left_el->l_recs[i];
right_el->l_recs[0] = move_rec;
/*
* Clear out the record we just copied and shift everything
* over, leaving an empty extent in the left leaf.
*
* We temporarily subtract from next_free_rec so that the
* shift will lose the tail record (which is now defunct).
*/
le16_add_cpu(&left_el->l_next_free_rec, -1);
ocfs2_shift_records_right(left_el);
memset(&left_el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
le16_add_cpu(&left_el->l_next_free_rec, 1);
ret = ocfs2_journal_dirty(handle, left_leaf_bh);
if (ret) {
mlog_errno(ret);
goto out;
}
ocfs2_complete_edge_insert(inode, handle, left_path, right_path,
subtree_index);
out:
return ret;
}
/*
* Given a full path, determine what cpos value would return us a path
* containing the leaf immediately to the left of the current one.
*
* Will return zero if the path passed in is already the leftmost path.
*/
static int ocfs2_find_cpos_for_left_leaf(struct super_block *sb,
struct ocfs2_path *path, u32 *cpos)
{
int i, j, ret = 0;
u64 blkno;
struct ocfs2_extent_list *el;
BUG_ON(path->p_tree_depth == 0);
*cpos = 0;
blkno = path_leaf_bh(path)->b_blocknr;
/* Start at the tree node just above the leaf and work our way up. */
i = path->p_tree_depth - 1;
while (i >= 0) {
el = path->p_node[i].el;
/*
* Find the extent record just before the one in our
* path.
*/
for(j = 0; j < le16_to_cpu(el->l_next_free_rec); j++) {
if (le64_to_cpu(el->l_recs[j].e_blkno) == blkno) {
if (j == 0) {
if (i == 0) {
/*
* We've determined that the
* path specified is already
* the leftmost one - return a
* cpos of zero.
*/
goto out;
}
/*
* The leftmost record points to our
* leaf - we need to travel up the
* tree one level.
*/
goto next_node;
}
*cpos = le32_to_cpu(el->l_recs[j - 1].e_cpos);
*cpos = *cpos + ocfs2_rec_clusters(el,
&el->l_recs[j - 1]);
*cpos = *cpos - 1;
goto out;
}
}
/*
* If we got here, we never found a valid node where
* the tree indicated one should be.
*/
ocfs2_error(sb,
"Invalid extent tree at extent block %llu\n",
(unsigned long long)blkno);
ret = -EROFS;
goto out;
next_node:
blkno = path->p_node[i].bh->b_blocknr;
i--;
}
out:
return ret;
}
/*
* Extend the transaction by enough credits to complete the rotation,
* and still leave at least the original number of credits allocated
* to this transaction.
*/
static int ocfs2_extend_rotate_transaction(handle_t *handle, int subtree_depth,
int op_credits,
struct ocfs2_path *path)
{
int credits = (path->p_tree_depth - subtree_depth) * 2 + 1 + op_credits;
if (handle->h_buffer_credits < credits)
return ocfs2_extend_trans(handle, credits);
return 0;
}
/*
* Trap the case where we're inserting into the theoretical range past
* the _actual_ left leaf range. Otherwise, we'll rotate a record
* whose cpos is less than ours into the right leaf.
*
* It's only necessary to look at the rightmost record of the left
* leaf because the logic that calls us should ensure that the
* theoretical ranges in the path components above the leaves are
* correct.
*/
static int ocfs2_rotate_requires_path_adjustment(struct ocfs2_path *left_path,
u32 insert_cpos)
{
struct ocfs2_extent_list *left_el;
struct ocfs2_extent_rec *rec;
int next_free;
left_el = path_leaf_el(left_path);
next_free = le16_to_cpu(left_el->l_next_free_rec);
rec = &left_el->l_recs[next_free - 1];
if (insert_cpos > le32_to_cpu(rec->e_cpos))
return 1;
return 0;
}
static int ocfs2_leftmost_rec_contains(struct ocfs2_extent_list *el, u32 cpos)
{
int next_free = le16_to_cpu(el->l_next_free_rec);
unsigned int range;
struct ocfs2_extent_rec *rec;
if (next_free == 0)
return 0;
rec = &el->l_recs[0];
if (ocfs2_is_empty_extent(rec)) {
/* Empty list. */
if (next_free == 1)
return 0;
rec = &el->l_recs[1];
}
range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
if (cpos >= le32_to_cpu(rec->e_cpos) && cpos < range)
return 1;
return 0;
}
/*
* Rotate all the records in a btree right one record, starting at insert_cpos.
*
* The path to the rightmost leaf should be passed in.
*
* The array is assumed to be large enough to hold an entire path (tree depth).
*
* Upon succesful return from this function:
*
* - The 'right_path' array will contain a path to the leaf block
* whose range contains e_cpos.
* - That leaf block will have a single empty extent in list index 0.
* - In the case that the rotation requires a post-insert update,
* *ret_left_path will contain a valid path which can be passed to
* ocfs2_insert_path().
*/
static int ocfs2_rotate_tree_right(struct inode *inode,
handle_t *handle,
enum ocfs2_split_type split,
u32 insert_cpos,
struct ocfs2_path *right_path,
struct ocfs2_path **ret_left_path)
{
int ret, start, orig_credits = handle->h_buffer_credits;
u32 cpos;
struct ocfs2_path *left_path = NULL;
*ret_left_path = NULL;
left_path = ocfs2_new_path(path_root_bh(right_path),
path_root_el(right_path));
if (!left_path) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, right_path, &cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
mlog(0, "Insert: %u, first left path cpos: %u\n", insert_cpos, cpos);
/*
* What we want to do here is:
*
* 1) Start with the rightmost path.
*
* 2) Determine a path to the leaf block directly to the left
* of that leaf.
*
* 3) Determine the 'subtree root' - the lowest level tree node
* which contains a path to both leaves.
*
* 4) Rotate the subtree.
*
* 5) Find the next subtree by considering the left path to be
* the new right path.
*
* The check at the top of this while loop also accepts
* insert_cpos == cpos because cpos is only a _theoretical_
* value to get us the left path - insert_cpos might very well
* be filling that hole.
*
* Stop at a cpos of '0' because we either started at the
* leftmost branch (i.e., a tree with one branch and a
* rotation inside of it), or we've gone as far as we can in
* rotating subtrees.
*/
while (cpos && insert_cpos <= cpos) {
mlog(0, "Rotating a tree: ins. cpos: %u, left path cpos: %u\n",
insert_cpos, cpos);
ret = ocfs2_find_path(inode, left_path, cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
mlog_bug_on_msg(path_leaf_bh(left_path) ==
path_leaf_bh(right_path),
"Inode %lu: error during insert of %u "
"(left path cpos %u) results in two identical "
"paths ending at %llu\n",
inode->i_ino, insert_cpos, cpos,
(unsigned long long)
path_leaf_bh(left_path)->b_blocknr);
if (split == SPLIT_NONE &&
ocfs2_rotate_requires_path_adjustment(left_path,
insert_cpos)) {
/*
* We've rotated the tree as much as we
* should. The rest is up to
* ocfs2_insert_path() to complete, after the
* record insertion. We indicate this
* situation by returning the left path.
*
* The reason we don't adjust the records here
* before the record insert is that an error
* later might break the rule where a parent
* record e_cpos will reflect the actual
* e_cpos of the 1st nonempty record of the
* child list.
*/
*ret_left_path = left_path;
goto out_ret_path;
}
start = ocfs2_find_subtree_root(inode, left_path, right_path);
mlog(0, "Subtree root at index %d (blk %llu, depth %d)\n",
start,
(unsigned long long) right_path->p_node[start].bh->b_blocknr,
right_path->p_tree_depth);
ret = ocfs2_extend_rotate_transaction(handle, start,
orig_credits, right_path);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_rotate_subtree_right(inode, handle, left_path,
right_path, start);
if (ret) {
mlog_errno(ret);
goto out;
}
if (split != SPLIT_NONE &&
ocfs2_leftmost_rec_contains(path_leaf_el(right_path),
insert_cpos)) {
/*
* A rotate moves the rightmost left leaf
* record over to the leftmost right leaf
* slot. If we're doing an extent split
* instead of a real insert, then we have to
* check that the extent to be split wasn't
* just moved over. If it was, then we can
* exit here, passing left_path back -
* ocfs2_split_extent() is smart enough to
* search both leaves.
*/
*ret_left_path = left_path;
goto out_ret_path;
}
/*
* There is no need to re-read the next right path
* as we know that it'll be our current left
* path. Optimize by copying values instead.
*/
ocfs2_mv_path(right_path, left_path);
ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, right_path,
&cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
}
out:
ocfs2_free_path(left_path);
out_ret_path:
return ret;
}
static void ocfs2_update_edge_lengths(struct inode *inode, handle_t *handle,
struct ocfs2_path *path)
{
int i, idx;
struct ocfs2_extent_rec *rec;
struct ocfs2_extent_list *el;
struct ocfs2_extent_block *eb;
u32 range;
/* Path should always be rightmost. */
eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
BUG_ON(eb->h_next_leaf_blk != 0ULL);
el = &eb->h_list;
BUG_ON(le16_to_cpu(el->l_next_free_rec) == 0);
idx = le16_to_cpu(el->l_next_free_rec) - 1;
rec = &el->l_recs[idx];
range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
for (i = 0; i < path->p_tree_depth; i++) {
el = path->p_node[i].el;
idx = le16_to_cpu(el->l_next_free_rec) - 1;
rec = &el->l_recs[idx];
rec->e_int_clusters = cpu_to_le32(range);
le32_add_cpu(&rec->e_int_clusters, -le32_to_cpu(rec->e_cpos));
ocfs2_journal_dirty(handle, path->p_node[i].bh);
}
}
static void ocfs2_unlink_path(struct inode *inode, handle_t *handle,
struct ocfs2_cached_dealloc_ctxt *dealloc,
struct ocfs2_path *path, int unlink_start)
{
int ret, i;
struct ocfs2_extent_block *eb;
struct ocfs2_extent_list *el;
struct buffer_head *bh;
for(i = unlink_start; i < path_num_items(path); i++) {
bh = path->p_node[i].bh;
eb = (struct ocfs2_extent_block *)bh->b_data;
/*
* Not all nodes might have had their final count
* decremented by the caller - handle this here.
*/
el = &eb->h_list;
if (le16_to_cpu(el->l_next_free_rec) > 1) {
mlog(ML_ERROR,
"Inode %llu, attempted to remove extent block "
"%llu with %u records\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(unsigned long long)le64_to_cpu(eb->h_blkno),
le16_to_cpu(el->l_next_free_rec));
ocfs2_journal_dirty(handle, bh);
ocfs2_remove_from_cache(inode, bh);
continue;
}
el->l_next_free_rec = 0;
memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
ocfs2_journal_dirty(handle, bh);
ret = ocfs2_cache_extent_block_free(dealloc, eb);
if (ret)
mlog_errno(ret);
ocfs2_remove_from_cache(inode, bh);
}
}
static void ocfs2_unlink_subtree(struct inode *inode, handle_t *handle,
struct ocfs2_path *left_path,
struct ocfs2_path *right_path,
int subtree_index,
struct ocfs2_cached_dealloc_ctxt *dealloc)
{
int i;
struct buffer_head *root_bh = left_path->p_node[subtree_index].bh;
struct ocfs2_extent_list *root_el = left_path->p_node[subtree_index].el;
struct ocfs2_extent_list *el;
struct ocfs2_extent_block *eb;
el = path_leaf_el(left_path);
eb = (struct ocfs2_extent_block *)right_path->p_node[subtree_index + 1].bh->b_data;
for(i = 1; i < le16_to_cpu(root_el->l_next_free_rec); i++)
if (root_el->l_recs[i].e_blkno == eb->h_blkno)
break;
BUG_ON(i >= le16_to_cpu(root_el->l_next_free_rec));
memset(&root_el->l_recs[i], 0, sizeof(struct ocfs2_extent_rec));
le16_add_cpu(&root_el->l_next_free_rec, -1);
eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
eb->h_next_leaf_blk = 0;
ocfs2_journal_dirty(handle, root_bh);
ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
ocfs2_unlink_path(inode, handle, dealloc, right_path,
subtree_index + 1);
}
static int ocfs2_rotate_subtree_left(struct inode *inode, handle_t *handle,
struct ocfs2_path *left_path,
struct ocfs2_path *right_path,
int subtree_index,
struct ocfs2_cached_dealloc_ctxt *dealloc,
int *deleted)
{
int ret, i, del_right_subtree = 0, right_has_empty = 0;
struct buffer_head *root_bh, *di_bh = path_root_bh(right_path);
struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
struct ocfs2_extent_list *right_leaf_el, *left_leaf_el;
struct ocfs2_extent_block *eb;
*deleted = 0;
right_leaf_el = path_leaf_el(right_path);
left_leaf_el = path_leaf_el(left_path);
root_bh = left_path->p_node[subtree_index].bh;
BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
if (!ocfs2_is_empty_extent(&left_leaf_el->l_recs[0]))
return 0;
eb = (struct ocfs2_extent_block *)path_leaf_bh(right_path)->b_data;
if (ocfs2_is_empty_extent(&right_leaf_el->l_recs[0])) {
/*
* It's legal for us to proceed if the right leaf is
* the rightmost one and it has an empty extent. There
* are two cases to handle - whether the leaf will be
* empty after removal or not. If the leaf isn't empty
* then just remove the empty extent up front. The
* next block will handle empty leaves by flagging
* them for unlink.
*
* Non rightmost leaves will throw -EAGAIN and the
* caller can manually move the subtree and retry.
*/
if (eb->h_next_leaf_blk != 0ULL)
return -EAGAIN;
if (le16_to_cpu(right_leaf_el->l_next_free_rec) > 1) {
ret = ocfs2_journal_access(handle, inode,
path_leaf_bh(right_path),
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
ocfs2_remove_empty_extent(right_leaf_el);
} else
right_has_empty = 1;
}
if (eb->h_next_leaf_blk == 0ULL &&
le16_to_cpu(right_leaf_el->l_next_free_rec) == 1) {
/*
* We have to update i_last_eb_blk during the meta
* data delete.
*/
ret = ocfs2_journal_access(handle, inode, di_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
del_right_subtree = 1;
}
/*
* Getting here with an empty extent in the right path implies
* that it's the rightmost path and will be deleted.
*/
BUG_ON(right_has_empty && !del_right_subtree);
ret = ocfs2_journal_access(handle, inode, root_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
for(i = subtree_index + 1; i < path_num_items(right_path); i++) {
ret = ocfs2_journal_access(handle, inode,
right_path->p_node[i].bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_journal_access(handle, inode,
left_path->p_node[i].bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
}
if (!right_has_empty) {
/*
* Only do this if we're moving a real
* record. Otherwise, the action is delayed until
* after removal of the right path in which case we
* can do a simple shift to remove the empty extent.
*/
ocfs2_rotate_leaf(left_leaf_el, &right_leaf_el->l_recs[0]);
memset(&right_leaf_el->l_recs[0], 0,
sizeof(struct ocfs2_extent_rec));
}
if (eb->h_next_leaf_blk == 0ULL) {
/*
* Move recs over to get rid of empty extent, decrease
* next_free. This is allowed to remove the last
* extent in our leaf (setting l_next_free_rec to
* zero) - the delete code below won't care.
*/
ocfs2_remove_empty_extent(right_leaf_el);
}
ret = ocfs2_journal_dirty(handle, path_leaf_bh(left_path));
if (ret)
mlog_errno(ret);
ret = ocfs2_journal_dirty(handle, path_leaf_bh(right_path));
if (ret)
mlog_errno(ret);
if (del_right_subtree) {
ocfs2_unlink_subtree(inode, handle, left_path, right_path,
subtree_index, dealloc);
ocfs2_update_edge_lengths(inode, handle, left_path);
eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
di->i_last_eb_blk = eb->h_blkno;
/*
* Removal of the extent in the left leaf was skipped
* above so we could delete the right path
* 1st.
*/
if (right_has_empty)
ocfs2_remove_empty_extent(left_leaf_el);
ret = ocfs2_journal_dirty(handle, di_bh);
if (ret)
mlog_errno(ret);
*deleted = 1;
} else
ocfs2_complete_edge_insert(inode, handle, left_path, right_path,
subtree_index);
out:
return ret;
}
/*
* Given a full path, determine what cpos value would return us a path
* containing the leaf immediately to the right of the current one.
*
* Will return zero if the path passed in is already the rightmost path.
*
* This looks similar, but is subtly different to
* ocfs2_find_cpos_for_left_leaf().
*/
static int ocfs2_find_cpos_for_right_leaf(struct super_block *sb,
struct ocfs2_path *path, u32 *cpos)
{
int i, j, ret = 0;
u64 blkno;
struct ocfs2_extent_list *el;
*cpos = 0;
if (path->p_tree_depth == 0)
return 0;
blkno = path_leaf_bh(path)->b_blocknr;
/* Start at the tree node just above the leaf and work our way up. */
i = path->p_tree_depth - 1;
while (i >= 0) {
int next_free;
el = path->p_node[i].el;
/*
* Find the extent record just after the one in our
* path.
*/
next_free = le16_to_cpu(el->l_next_free_rec);
for(j = 0; j < le16_to_cpu(el->l_next_free_rec); j++) {
if (le64_to_cpu(el->l_recs[j].e_blkno) == blkno) {
if (j == (next_free - 1)) {
if (i == 0) {
/*
* We've determined that the
* path specified is already
* the rightmost one - return a
* cpos of zero.
*/
goto out;
}
/*
* The rightmost record points to our
* leaf - we need to travel up the
* tree one level.
*/
goto next_node;
}
*cpos = le32_to_cpu(el->l_recs[j + 1].e_cpos);
goto out;
}
}
/*
* If we got here, we never found a valid node where
* the tree indicated one should be.
*/
ocfs2_error(sb,
"Invalid extent tree at extent block %llu\n",
(unsigned long long)blkno);
ret = -EROFS;
goto out;
next_node:
blkno = path->p_node[i].bh->b_blocknr;
i--;
}
out:
return ret;
}
static int ocfs2_rotate_rightmost_leaf_left(struct inode *inode,
handle_t *handle,
struct buffer_head *bh,
struct ocfs2_extent_list *el)
{
int ret;
if (!ocfs2_is_empty_extent(&el->l_recs[0]))
return 0;
ret = ocfs2_journal_access(handle, inode, bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
ocfs2_remove_empty_extent(el);
ret = ocfs2_journal_dirty(handle, bh);
if (ret)
mlog_errno(ret);
out:
return ret;
}
static int __ocfs2_rotate_tree_left(struct inode *inode,
handle_t *handle, int orig_credits,
struct ocfs2_path *path,
struct ocfs2_cached_dealloc_ctxt *dealloc,
struct ocfs2_path **empty_extent_path)
{
int ret, subtree_root, deleted;
u32 right_cpos;
struct ocfs2_path *left_path = NULL;
struct ocfs2_path *right_path = NULL;
BUG_ON(!ocfs2_is_empty_extent(&(path_leaf_el(path)->l_recs[0])));
*empty_extent_path = NULL;
ret = ocfs2_find_cpos_for_right_leaf(inode->i_sb, path,
&right_cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
left_path = ocfs2_new_path(path_root_bh(path),
path_root_el(path));
if (!left_path) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
ocfs2_cp_path(left_path, path);
right_path = ocfs2_new_path(path_root_bh(path),
path_root_el(path));
if (!right_path) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
while (right_cpos) {
ret = ocfs2_find_path(inode, right_path, right_cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
subtree_root = ocfs2_find_subtree_root(inode, left_path,
right_path);
mlog(0, "Subtree root at index %d (blk %llu, depth %d)\n",
subtree_root,
(unsigned long long)
right_path->p_node[subtree_root].bh->b_blocknr,
right_path->p_tree_depth);
ret = ocfs2_extend_rotate_transaction(handle, subtree_root,
orig_credits, left_path);
if (ret) {
mlog_errno(ret);
goto out;
}
/*
* Caller might still want to make changes to the
* tree root, so re-add it to the journal here.
*/
ret = ocfs2_journal_access(handle, inode,
path_root_bh(left_path),
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_rotate_subtree_left(inode, handle, left_path,
right_path, subtree_root,
dealloc, &deleted);
if (ret == -EAGAIN) {
/*
* The rotation has to temporarily stop due to
* the right subtree having an empty
* extent. Pass it back to the caller for a
* fixup.
*/
*empty_extent_path = right_path;
right_path = NULL;
goto out;
}
if (ret) {
mlog_errno(ret);
goto out;
}
/*
* The subtree rotate might have removed records on
* the rightmost edge. If so, then rotation is
* complete.
*/
if (deleted)
break;
ocfs2_mv_path(left_path, right_path);
ret = ocfs2_find_cpos_for_right_leaf(inode->i_sb, left_path,
&right_cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
}
out:
ocfs2_free_path(right_path);
ocfs2_free_path(left_path);
return ret;
}
static int ocfs2_remove_rightmost_path(struct inode *inode, handle_t *handle,
struct ocfs2_path *path,
struct ocfs2_cached_dealloc_ctxt *dealloc)
{
int ret, subtree_index;
u32 cpos;
struct ocfs2_path *left_path = NULL;
struct ocfs2_dinode *di;
struct ocfs2_extent_block *eb;
struct ocfs2_extent_list *el;
/*
* XXX: This code assumes that the root is an inode, which is
* true for now but may change as tree code gets generic.
*/
di = (struct ocfs2_dinode *)path_root_bh(path)->b_data;
if (!OCFS2_IS_VALID_DINODE(di)) {
ret = -EIO;
ocfs2_error(inode->i_sb,
"Inode %llu has invalid path root",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
goto out;
}
/*
* There's two ways we handle this depending on
* whether path is the only existing one.
*/
ret = ocfs2_extend_rotate_transaction(handle, 0,
handle->h_buffer_credits,
path);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_journal_access_path(inode, handle, path);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, path, &cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
if (cpos) {
/*
* We have a path to the left of this one - it needs
* an update too.
*/
left_path = ocfs2_new_path(path_root_bh(path),
path_root_el(path));
if (!left_path) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
ret = ocfs2_find_path(inode, left_path, cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_journal_access_path(inode, handle, left_path);
if (ret) {
mlog_errno(ret);
goto out;
}
subtree_index = ocfs2_find_subtree_root(inode, left_path, path);
ocfs2_unlink_subtree(inode, handle, left_path, path,
subtree_index, dealloc);
ocfs2_update_edge_lengths(inode, handle, left_path);
eb = (struct ocfs2_extent_block *)path_leaf_bh(left_path)->b_data;
di->i_last_eb_blk = eb->h_blkno;
} else {
/*
* 'path' is also the leftmost path which
* means it must be the only one. This gets
* handled differently because we want to
* revert the inode back to having extents
* in-line.
*/
ocfs2_unlink_path(inode, handle, dealloc, path, 1);
el = &di->id2.i_list;
el->l_tree_depth = 0;
el->l_next_free_rec = 0;
memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
di->i_last_eb_blk = 0;
}
ocfs2_journal_dirty(handle, path_root_bh(path));
out:
ocfs2_free_path(left_path);
return ret;
}
/*
* Left rotation of btree records.
*
* In many ways, this is (unsurprisingly) the opposite of right
* rotation. We start at some non-rightmost path containing an empty
* extent in the leaf block. The code works its way to the rightmost
* path by rotating records to the left in every subtree.
*
* This is used by any code which reduces the number of extent records
* in a leaf. After removal, an empty record should be placed in the
* leftmost list position.
*
* This won't handle a length update of the rightmost path records if
* the rightmost tree leaf record is removed so the caller is
* responsible for detecting and correcting that.
*/
static int ocfs2_rotate_tree_left(struct inode *inode, handle_t *handle,
struct ocfs2_path *path,
struct ocfs2_cached_dealloc_ctxt *dealloc)
{
int ret, orig_credits = handle->h_buffer_credits;
struct ocfs2_path *tmp_path = NULL, *restart_path = NULL;
struct ocfs2_extent_block *eb;
struct ocfs2_extent_list *el;
el = path_leaf_el(path);
if (!ocfs2_is_empty_extent(&el->l_recs[0]))
return 0;
if (path->p_tree_depth == 0) {
rightmost_no_delete:
/*
* In-inode extents. This is trivially handled, so do
* it up front.
*/
ret = ocfs2_rotate_rightmost_leaf_left(inode, handle,
path_leaf_bh(path),
path_leaf_el(path));
if (ret)
mlog_errno(ret);
goto out;
}
/*
* Handle rightmost branch now. There's several cases:
* 1) simple rotation leaving records in there. That's trivial.
* 2) rotation requiring a branch delete - there's no more
* records left. Two cases of this:
* a) There are branches to the left.
* b) This is also the leftmost (the only) branch.
*
* 1) is handled via ocfs2_rotate_rightmost_leaf_left()
* 2a) we need the left branch so that we can update it with the unlink
* 2b) we need to bring the inode back to inline extents.
*/
eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
el = &eb->h_list;
if (eb->h_next_leaf_blk == 0) {
/*
* This gets a bit tricky if we're going to delete the
* rightmost path. Get the other cases out of the way
* 1st.
*/
if (le16_to_cpu(el->l_next_free_rec) > 1)
goto rightmost_no_delete;
if (le16_to_cpu(el->l_next_free_rec) == 0) {
ret = -EIO;
ocfs2_error(inode->i_sb,
"Inode %llu has empty extent block at %llu",
(unsigned long long)OCFS2_I(inode)->ip_blkno,
(unsigned long long)le64_to_cpu(eb->h_blkno));
goto out;
}
/*
* XXX: The caller can not trust "path" any more after
* this as it will have been deleted. What do we do?
*
* In theory the rotate-for-merge code will never get
* here because it'll always ask for a rotate in a
* nonempty list.
*/
ret = ocfs2_remove_rightmost_path(inode, handle, path,
dealloc);
if (ret)
mlog_errno(ret);
goto out;
}
/*
* Now we can loop, remembering the path we get from -EAGAIN
* and restarting from there.
*/
try_rotate:
ret = __ocfs2_rotate_tree_left(inode, handle, orig_credits, path,
dealloc, &restart_path);
if (ret && ret != -EAGAIN) {
mlog_errno(ret);
goto out;
}
while (ret == -EAGAIN) {
tmp_path = restart_path;
restart_path = NULL;
ret = __ocfs2_rotate_tree_left(inode, handle, orig_credits,
tmp_path, dealloc,
&restart_path);
if (ret && ret != -EAGAIN) {
mlog_errno(ret);
goto out;
}
ocfs2_free_path(tmp_path);
tmp_path = NULL;
if (ret == 0)
goto try_rotate;
}
out:
ocfs2_free_path(tmp_path);
ocfs2_free_path(restart_path);
return ret;
}
static void ocfs2_cleanup_merge(struct ocfs2_extent_list *el,
int index)
{
struct ocfs2_extent_rec *rec = &el->l_recs[index];
unsigned int size;
if (rec->e_leaf_clusters == 0) {
/*
* We consumed all of the merged-from record. An empty
* extent cannot exist anywhere but the 1st array
* position, so move things over if the merged-from
* record doesn't occupy that position.
*
* This creates a new empty extent so the caller
* should be smart enough to have removed any existing
* ones.
*/
if (index > 0) {
BUG_ON(ocfs2_is_empty_extent(&el->l_recs[0]));
size = index * sizeof(struct ocfs2_extent_rec);
memmove(&el->l_recs[1], &el->l_recs[0], size);
}
/*
* Always memset - the caller doesn't check whether it
* created an empty extent, so there could be junk in
* the other fields.
*/
memset(&el->l_recs[0], 0, sizeof(struct ocfs2_extent_rec));
}
}
static int ocfs2_get_right_path(struct inode *inode,
struct ocfs2_path *left_path,
struct ocfs2_path **ret_right_path)
{
int ret;
u32 right_cpos;
struct ocfs2_path *right_path = NULL;
struct ocfs2_extent_list *left_el;
*ret_right_path = NULL;
/* This function shouldn't be called for non-trees. */
BUG_ON(left_path->p_tree_depth == 0);
left_el = path_leaf_el(left_path);
BUG_ON(left_el->l_next_free_rec != left_el->l_count);
ret = ocfs2_find_cpos_for_right_leaf(inode->i_sb, left_path,
&right_cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
/* This function shouldn't be called for the rightmost leaf. */
BUG_ON(right_cpos == 0);
right_path = ocfs2_new_path(path_root_bh(left_path),
path_root_el(left_path));
if (!right_path) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
ret = ocfs2_find_path(inode, right_path, right_cpos);
if (ret) {
mlog_errno(ret);
goto out;
}
*ret_right_path = right_path;
out:
if (ret)
ocfs2_free_path(right_path);
return ret;
}
/*
* Remove split_rec clusters from the record at index and merge them
* onto the beginning of the record "next" to it.
* For index < l_count - 1, the next means the extent rec at index + 1.
* For index == l_count - 1, the "next" means the 1st extent rec of the
* next extent block.
*/
static int ocfs2_merge_rec_right(struct inode *inode,
struct ocfs2_path *left_path,
handle_t *handle,
struct ocfs2_extent_rec *split_rec,
int index)
{
int ret, next_free, i;
unsigned int split_clusters = le16_to_cpu(split_rec->e_leaf_clusters);
struct ocfs2_extent_rec *left_rec;
struct ocfs2_extent_rec *right_rec;
struct ocfs2_extent_list *right_el;
struct ocfs2_path *right_path = NULL;
int subtree_index = 0;
struct ocfs2_extent_list *el = path_leaf_el(left_path);
struct buffer_head *bh = path_leaf_bh(left_path);
struct buffer_head *root_bh = NULL;
BUG_ON(index >= le16_to_cpu(el->l_next_free_rec));
left_rec = &el->l_recs[index];
if (index == le16_to_cpu(el->l_next_free_rec) - 1 &&
le16_to_cpu(el->l_next_free_rec) == le16_to_cpu(el->l_count)) {
/* we meet with a cross extent block merge. */
ret = ocfs2_get_right_path(inode, left_path, &right_path);
if (ret) {
mlog_errno(ret);
goto out;
}
right_el = path_leaf_el(right_path);
next_free = le16_to_cpu(right_el->l_next_free_rec);
BUG_ON(next_free <= 0);
right_rec = &right_el->l_recs[0];
if (ocfs2_is_empty_extent(right_rec)) {
BUG_ON(next_free <= 1);
right_rec = &right_el->l_recs[1];
}
BUG_ON(le32_to_cpu(left_rec->e_cpos) +
le16_to_cpu(left_rec->e_leaf_clusters) !=
le32_to_cpu(right_rec->e_cpos));
subtree_index = ocfs2_find_subtree_root(inode,
left_path, right_path);
ret = ocfs2_extend_rotate_transaction(handle, subtree_index,
handle->h_buffer_credits,
right_path);
if (ret) {
mlog_errno(ret);
goto out;
}
root_bh = left_path->p_node[subtree_index].bh;
BUG_ON(root_bh != right_path->p_node[subtree_index].bh);
ret = ocfs2_journal_access(handle, inode, root_bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
for (i = subtree_index + 1;
i < path_num_items(right_path); i++) {
ret = ocfs2_journal_access(handle, inode,
right_path->p_node[i].bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
ret = ocfs2_journal_access(handle, inode,
left_path->p_node[i].bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
}
} else {
BUG_ON(index == le16_to_cpu(el->l_next_free_rec) - 1);
right_rec = &el->l_recs[index + 1];
}
ret = ocfs2_journal_access(handle, inode, bh,
OCFS2_JOURNAL_ACCESS_WRITE);
if (ret) {
mlog_errno(ret);
goto out;
}
le16_add_cpu(&left_rec->e_leaf_clusters, -split_clusters);
le32_add_cpu(&right_rec->e_cpos, -split_clusters);
le64_add_cpu(&right_rec->e_blkno,
-ocfs2_clusters_to_blocks(inode->i_sb, split_clusters));
le16_add_cpu(&right_rec->e_leaf_clusters, split_clusters);
ocfs2_cleanup_merge(el, index);
ret = ocfs2_journal_dirty(handle, bh);
if (ret)
mlog_errno(ret);
if (right_path) {
ret = ocfs2_journal_dirty(handle, path_leaf_bh(right_path));
if (ret)
mlog_errno(ret);
ocfs2_complete_edge_insert(inode, handle, left_path,
right_path, subtree_index);
}