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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/ocfs2/move_extents.c
Initial import
Diffstat (limited to 'fs/ocfs2/move_extents.c')
-rw-r--r--fs/ocfs2/move_extents.c1075
1 files changed, 1075 insertions, 0 deletions
diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
new file mode 100644
index 000000000..56a768d06
--- /dev/null
+++ b/fs/ocfs2/move_extents.c
@@ -0,0 +1,1075 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * move_extents.c
+ *
+ * Copyright (C) 2011 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 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.
+ */
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/mount.h>
+#include <linux/swap.h>
+
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+#include "ocfs2_ioctl.h"
+
+#include "alloc.h"
+#include "aops.h"
+#include "dlmglue.h"
+#include "extent_map.h"
+#include "inode.h"
+#include "journal.h"
+#include "suballoc.h"
+#include "uptodate.h"
+#include "super.h"
+#include "dir.h"
+#include "buffer_head_io.h"
+#include "sysfile.h"
+#include "refcounttree.h"
+#include "move_extents.h"
+
+struct ocfs2_move_extents_context {
+ struct inode *inode;
+ struct file *file;
+ int auto_defrag;
+ int partial;
+ int credits;
+ u32 new_phys_cpos;
+ u32 clusters_moved;
+ u64 refcount_loc;
+ struct ocfs2_move_extents *range;
+ struct ocfs2_extent_tree et;
+ struct ocfs2_alloc_context *meta_ac;
+ struct ocfs2_alloc_context *data_ac;
+ struct ocfs2_cached_dealloc_ctxt dealloc;
+};
+
+static int __ocfs2_move_extent(handle_t *handle,
+ struct ocfs2_move_extents_context *context,
+ u32 cpos, u32 len, u32 p_cpos, u32 new_p_cpos,
+ int ext_flags)
+{
+ int ret = 0, index;
+ struct inode *inode = context->inode;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct ocfs2_extent_rec *rec, replace_rec;
+ struct ocfs2_path *path = NULL;
+ struct ocfs2_extent_list *el;
+ u64 ino = ocfs2_metadata_cache_owner(context->et.et_ci);
+ u64 old_blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cpos);
+
+ ret = ocfs2_duplicate_clusters_by_page(handle, inode, cpos,
+ p_cpos, new_p_cpos, len);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ memset(&replace_rec, 0, sizeof(replace_rec));
+ replace_rec.e_cpos = cpu_to_le32(cpos);
+ replace_rec.e_leaf_clusters = cpu_to_le16(len);
+ replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(inode->i_sb,
+ new_p_cpos));
+
+ path = ocfs2_new_path_from_et(&context->et);
+ if (!path) {
+ ret = -ENOMEM;
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ret = ocfs2_find_path(INODE_CACHE(inode), path, cpos);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ el = path_leaf_el(path);
+
+ index = ocfs2_search_extent_list(el, cpos);
+ if (index == -1) {
+ ocfs2_error(inode->i_sb,
+ "Inode %llu has an extent at cpos %u which can no "
+ "longer be found.\n",
+ (unsigned long long)ino, cpos);
+ ret = -EROFS;
+ goto out;
+ }
+
+ rec = &el->l_recs[index];
+
+ BUG_ON(ext_flags != rec->e_flags);
+ /*
+ * after moving/defraging to new location, the extent is not going
+ * to be refcounted anymore.
+ */
+ replace_rec.e_flags = ext_flags & ~OCFS2_EXT_REFCOUNTED;
+
+ ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode),
+ context->et.et_root_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ret = ocfs2_split_extent(handle, &context->et, path, index,
+ &replace_rec, context->meta_ac,
+ &context->dealloc);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ocfs2_journal_dirty(handle, context->et.et_root_bh);
+
+ context->new_phys_cpos = new_p_cpos;
+
+ /*
+ * need I to append truncate log for old clusters?
+ */
+ if (old_blkno) {
+ if (ext_flags & OCFS2_EXT_REFCOUNTED)
+ ret = ocfs2_decrease_refcount(inode, handle,
+ ocfs2_blocks_to_clusters(osb->sb,
+ old_blkno),
+ len, context->meta_ac,
+ &context->dealloc, 1);
+ else
+ ret = ocfs2_truncate_log_append(osb, handle,
+ old_blkno, len);
+ }
+
+ ocfs2_update_inode_fsync_trans(handle, inode, 0);
+out:
+ ocfs2_free_path(path);
+ return ret;
+}
+
+/*
+ * lock allocators, and reserving appropriate number of bits for
+ * meta blocks and data clusters.
+ *
+ * in some cases, we don't need to reserve clusters, just let data_ac
+ * be NULL.
+ */
+static int ocfs2_lock_allocators_move_extents(struct inode *inode,
+ struct ocfs2_extent_tree *et,
+ u32 clusters_to_move,
+ u32 extents_to_split,
+ struct ocfs2_alloc_context **meta_ac,
+ struct ocfs2_alloc_context **data_ac,
+ int extra_blocks,
+ int *credits)
+{
+ int ret, num_free_extents;
+ unsigned int max_recs_needed = 2 * extents_to_split + clusters_to_move;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ num_free_extents = ocfs2_num_free_extents(osb, et);
+ if (num_free_extents < 0) {
+ ret = num_free_extents;
+ mlog_errno(ret);
+ goto out;
+ }
+
+ if (!num_free_extents ||
+ (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed))
+ extra_blocks += ocfs2_extend_meta_needed(et->et_root_el);
+
+ ret = ocfs2_reserve_new_metadata_blocks(osb, extra_blocks, meta_ac);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ if (data_ac) {
+ ret = ocfs2_reserve_clusters(osb, clusters_to_move, data_ac);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+ }
+
+ *credits += ocfs2_calc_extend_credits(osb->sb, et->et_root_el);
+
+ mlog(0, "reserve metadata_blocks: %d, data_clusters: %u, credits: %d\n",
+ extra_blocks, clusters_to_move, *credits);
+out:
+ if (ret) {
+ if (*meta_ac) {
+ ocfs2_free_alloc_context(*meta_ac);
+ *meta_ac = NULL;
+ }
+ }
+
+ return ret;
+}
+
+/*
+ * Using one journal handle to guarantee the data consistency in case
+ * crash happens anywhere.
+ *
+ * XXX: defrag can end up with finishing partial extent as requested,
+ * due to not enough contiguous clusters can be found in allocator.
+ */
+static int ocfs2_defrag_extent(struct ocfs2_move_extents_context *context,
+ u32 cpos, u32 phys_cpos, u32 *len, int ext_flags)
+{
+ int ret, credits = 0, extra_blocks = 0, partial = context->partial;
+ handle_t *handle;
+ struct inode *inode = context->inode;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct inode *tl_inode = osb->osb_tl_inode;
+ struct ocfs2_refcount_tree *ref_tree = NULL;
+ u32 new_phys_cpos, new_len;
+ u64 phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
+
+ if ((ext_flags & OCFS2_EXT_REFCOUNTED) && *len) {
+
+ BUG_ON(!(OCFS2_I(inode)->ip_dyn_features &
+ OCFS2_HAS_REFCOUNT_FL));
+
+ BUG_ON(!context->refcount_loc);
+
+ ret = ocfs2_lock_refcount_tree(osb, context->refcount_loc, 1,
+ &ref_tree, NULL);
+ if (ret) {
+ mlog_errno(ret);
+ return ret;
+ }
+
+ ret = ocfs2_prepare_refcount_change_for_del(inode,
+ context->refcount_loc,
+ phys_blkno,
+ *len,
+ &credits,
+ &extra_blocks);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+ }
+
+ ret = ocfs2_lock_allocators_move_extents(inode, &context->et, *len, 1,
+ &context->meta_ac,
+ &context->data_ac,
+ extra_blocks, &credits);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ /*
+ * should be using allocation reservation strategy there?
+ *
+ * if (context->data_ac)
+ * context->data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv;
+ */
+
+ mutex_lock(&tl_inode->i_mutex);
+
+ if (ocfs2_truncate_log_needs_flush(osb)) {
+ ret = __ocfs2_flush_truncate_log(osb);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out_unlock_mutex;
+ }
+ }
+
+ handle = ocfs2_start_trans(osb, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ mlog_errno(ret);
+ goto out_unlock_mutex;
+ }
+
+ ret = __ocfs2_claim_clusters(handle, context->data_ac, 1, *len,
+ &new_phys_cpos, &new_len);
+ if (ret) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+
+ /*
+ * allowing partial extent moving is kind of 'pros and cons', it makes
+ * whole defragmentation less likely to fail, on the contrary, the bad
+ * thing is it may make the fs even more fragmented after moving, let
+ * userspace make a good decision here.
+ */
+ if (new_len != *len) {
+ mlog(0, "len_claimed: %u, len: %u\n", new_len, *len);
+ if (!partial) {
+ context->range->me_flags &= ~OCFS2_MOVE_EXT_FL_COMPLETE;
+ ret = -ENOSPC;
+ goto out_commit;
+ }
+ }
+
+ mlog(0, "cpos: %u, phys_cpos: %u, new_phys_cpos: %u\n", cpos,
+ phys_cpos, new_phys_cpos);
+
+ ret = __ocfs2_move_extent(handle, context, cpos, new_len, phys_cpos,
+ new_phys_cpos, ext_flags);
+ if (ret)
+ mlog_errno(ret);
+
+ if (partial && (new_len != *len))
+ *len = new_len;
+
+ /*
+ * Here we should write the new page out first if we are
+ * in write-back mode.
+ */
+ ret = ocfs2_cow_sync_writeback(inode->i_sb, context->inode, cpos, *len);
+ if (ret)
+ mlog_errno(ret);
+
+out_commit:
+ ocfs2_commit_trans(osb, handle);
+
+out_unlock_mutex:
+ mutex_unlock(&tl_inode->i_mutex);
+
+ if (context->data_ac) {
+ ocfs2_free_alloc_context(context->data_ac);
+ context->data_ac = NULL;
+ }
+
+ if (context->meta_ac) {
+ ocfs2_free_alloc_context(context->meta_ac);
+ context->meta_ac = NULL;
+ }
+
+out:
+ if (ref_tree)
+ ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
+
+ return ret;
+}
+
+/*
+ * find the victim alloc group, where #blkno fits.
+ */
+static int ocfs2_find_victim_alloc_group(struct inode *inode,
+ u64 vict_blkno,
+ int type, int slot,
+ int *vict_bit,
+ struct buffer_head **ret_bh)
+{
+ int ret, i, bits_per_unit = 0;
+ u64 blkno;
+ char namebuf[40];
+
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct buffer_head *ac_bh = NULL, *gd_bh = NULL;
+ struct ocfs2_chain_list *cl;
+ struct ocfs2_chain_rec *rec;
+ struct ocfs2_dinode *ac_dinode;
+ struct ocfs2_group_desc *bg;
+
+ ocfs2_sprintf_system_inode_name(namebuf, sizeof(namebuf), type, slot);
+ ret = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
+ strlen(namebuf), &blkno);
+ if (ret) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = ocfs2_read_blocks_sync(osb, blkno, 1, &ac_bh);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ac_dinode = (struct ocfs2_dinode *)ac_bh->b_data;
+ cl = &(ac_dinode->id2.i_chain);
+ rec = &(cl->cl_recs[0]);
+
+ if (type == GLOBAL_BITMAP_SYSTEM_INODE)
+ bits_per_unit = osb->s_clustersize_bits -
+ inode->i_sb->s_blocksize_bits;
+ /*
+ * 'vict_blkno' was out of the valid range.
+ */
+ if ((vict_blkno < le64_to_cpu(rec->c_blkno)) ||
+ (vict_blkno >= ((u64)le32_to_cpu(ac_dinode->id1.bitmap1.i_total) <<
+ bits_per_unit))) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i++) {
+
+ rec = &(cl->cl_recs[i]);
+ if (!rec)
+ continue;
+
+ bg = NULL;
+
+ do {
+ if (!bg)
+ blkno = le64_to_cpu(rec->c_blkno);
+ else
+ blkno = le64_to_cpu(bg->bg_next_group);
+
+ if (gd_bh) {
+ brelse(gd_bh);
+ gd_bh = NULL;
+ }
+
+ ret = ocfs2_read_blocks_sync(osb, blkno, 1, &gd_bh);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ bg = (struct ocfs2_group_desc *)gd_bh->b_data;
+
+ if (vict_blkno < (le64_to_cpu(bg->bg_blkno) +
+ le16_to_cpu(bg->bg_bits))) {
+
+ *ret_bh = gd_bh;
+ *vict_bit = (vict_blkno - blkno) >>
+ bits_per_unit;
+ mlog(0, "find the victim group: #%llu, "
+ "total_bits: %u, vict_bit: %u\n",
+ blkno, le16_to_cpu(bg->bg_bits),
+ *vict_bit);
+ goto out;
+ }
+
+ } while (le64_to_cpu(bg->bg_next_group));
+ }
+
+ ret = -EINVAL;
+out:
+ brelse(ac_bh);
+
+ /*
+ * caller has to release the gd_bh properly.
+ */
+ return ret;
+}
+
+/*
+ * XXX: helper to validate and adjust moving goal.
+ */
+static int ocfs2_validate_and_adjust_move_goal(struct inode *inode,
+ struct ocfs2_move_extents *range)
+{
+ int ret, goal_bit = 0;
+
+ struct buffer_head *gd_bh = NULL;
+ struct ocfs2_group_desc *bg;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ int c_to_b = 1 << (osb->s_clustersize_bits -
+ inode->i_sb->s_blocksize_bits);
+
+ /*
+ * make goal become cluster aligned.
+ */
+ range->me_goal = ocfs2_block_to_cluster_start(inode->i_sb,
+ range->me_goal);
+ /*
+ * validate goal sits within global_bitmap, and return the victim
+ * group desc
+ */
+ ret = ocfs2_find_victim_alloc_group(inode, range->me_goal,
+ GLOBAL_BITMAP_SYSTEM_INODE,
+ OCFS2_INVALID_SLOT,
+ &goal_bit, &gd_bh);
+ if (ret)
+ goto out;
+
+ bg = (struct ocfs2_group_desc *)gd_bh->b_data;
+
+ /*
+ * moving goal is not allowd to start with a group desc blok(#0 blk)
+ * let's compromise to the latter cluster.
+ */
+ if (range->me_goal == le64_to_cpu(bg->bg_blkno))
+ range->me_goal += c_to_b;
+
+ /*
+ * movement is not gonna cross two groups.
+ */
+ if ((le16_to_cpu(bg->bg_bits) - goal_bit) * osb->s_clustersize <
+ range->me_len) {
+ ret = -EINVAL;
+ goto out;
+ }
+ /*
+ * more exact validations/adjustments will be performed later during
+ * moving operation for each extent range.
+ */
+ mlog(0, "extents get ready to be moved to #%llu block\n",
+ range->me_goal);
+
+out:
+ brelse(gd_bh);
+
+ return ret;
+}
+
+static void ocfs2_probe_alloc_group(struct inode *inode, struct buffer_head *bh,
+ int *goal_bit, u32 move_len, u32 max_hop,
+ u32 *phys_cpos)
+{
+ int i, used, last_free_bits = 0, base_bit = *goal_bit;
+ struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *)bh->b_data;
+ u32 base_cpos = ocfs2_blocks_to_clusters(inode->i_sb,
+ le64_to_cpu(gd->bg_blkno));
+
+ for (i = base_bit; i < le16_to_cpu(gd->bg_bits); i++) {
+
+ used = ocfs2_test_bit(i, (unsigned long *)gd->bg_bitmap);
+ if (used) {
+ /*
+ * we even tried searching the free chunk by jumping
+ * a 'max_hop' distance, but still failed.
+ */
+ if ((i - base_bit) > max_hop) {
+ *phys_cpos = 0;
+ break;
+ }
+
+ if (last_free_bits)
+ last_free_bits = 0;
+
+ continue;
+ } else
+ last_free_bits++;
+
+ if (last_free_bits == move_len) {
+ *goal_bit = i;
+ *phys_cpos = base_cpos + i;
+ break;
+ }
+ }
+
+ mlog(0, "found phys_cpos: %u to fit the wanted moving.\n", *phys_cpos);
+}
+
+static int ocfs2_move_extent(struct ocfs2_move_extents_context *context,
+ u32 cpos, u32 phys_cpos, u32 *new_phys_cpos,
+ u32 len, int ext_flags)
+{
+ int ret, credits = 0, extra_blocks = 0, goal_bit = 0;
+ handle_t *handle;
+ struct inode *inode = context->inode;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct inode *tl_inode = osb->osb_tl_inode;
+ struct inode *gb_inode = NULL;
+ struct buffer_head *gb_bh = NULL;
+ struct buffer_head *gd_bh = NULL;
+ struct ocfs2_group_desc *gd;
+ struct ocfs2_refcount_tree *ref_tree = NULL;
+ u32 move_max_hop = ocfs2_blocks_to_clusters(inode->i_sb,
+ context->range->me_threshold);
+ u64 phys_blkno, new_phys_blkno;
+
+ phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, phys_cpos);
+
+ if ((ext_flags & OCFS2_EXT_REFCOUNTED) && len) {
+
+ BUG_ON(!(OCFS2_I(inode)->ip_dyn_features &
+ OCFS2_HAS_REFCOUNT_FL));
+
+ BUG_ON(!context->refcount_loc);
+
+ ret = ocfs2_lock_refcount_tree(osb, context->refcount_loc, 1,
+ &ref_tree, NULL);
+ if (ret) {
+ mlog_errno(ret);
+ return ret;
+ }
+
+ ret = ocfs2_prepare_refcount_change_for_del(inode,
+ context->refcount_loc,
+ phys_blkno,
+ len,
+ &credits,
+ &extra_blocks);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+ }
+
+ ret = ocfs2_lock_allocators_move_extents(inode, &context->et, len, 1,
+ &context->meta_ac,
+ NULL, extra_blocks, &credits);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ /*
+ * need to count 2 extra credits for global_bitmap inode and
+ * group descriptor.
+ */
+ credits += OCFS2_INODE_UPDATE_CREDITS + 1;
+
+ /*
+ * ocfs2_move_extent() didn't reserve any clusters in lock_allocators()
+ * logic, while we still need to lock the global_bitmap.
+ */
+ gb_inode = ocfs2_get_system_file_inode(osb, GLOBAL_BITMAP_SYSTEM_INODE,
+ OCFS2_INVALID_SLOT);
+ if (!gb_inode) {
+ mlog(ML_ERROR, "unable to get global_bitmap inode\n");
+ ret = -EIO;
+ goto out;
+ }
+
+ mutex_lock(&gb_inode->i_mutex);
+
+ ret = ocfs2_inode_lock(gb_inode, &gb_bh, 1);
+ if (ret) {
+ mlog_errno(ret);
+ goto out_unlock_gb_mutex;
+ }
+
+ mutex_lock(&tl_inode->i_mutex);
+
+ handle = ocfs2_start_trans(osb, credits);
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ mlog_errno(ret);
+ goto out_unlock_tl_inode;
+ }
+
+ new_phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, *new_phys_cpos);
+ ret = ocfs2_find_victim_alloc_group(inode, new_phys_blkno,
+ GLOBAL_BITMAP_SYSTEM_INODE,
+ OCFS2_INVALID_SLOT,
+ &goal_bit, &gd_bh);
+ if (ret) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+
+ /*
+ * probe the victim cluster group to find a proper
+ * region to fit wanted movement, it even will perfrom
+ * a best-effort attempt by compromising to a threshold
+ * around the goal.
+ */
+ ocfs2_probe_alloc_group(inode, gd_bh, &goal_bit, len, move_max_hop,
+ new_phys_cpos);
+ if (!*new_phys_cpos) {
+ ret = -ENOSPC;
+ goto out_commit;
+ }
+
+ ret = __ocfs2_move_extent(handle, context, cpos, len, phys_cpos,
+ *new_phys_cpos, ext_flags);
+ if (ret) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+
+ gd = (struct ocfs2_group_desc *)gd_bh->b_data;
+ ret = ocfs2_alloc_dinode_update_counts(gb_inode, handle, gb_bh, len,
+ le16_to_cpu(gd->bg_chain));
+ if (ret) {
+ mlog_errno(ret);
+ goto out_commit;
+ }
+
+ ret = ocfs2_block_group_set_bits(handle, gb_inode, gd, gd_bh,
+ goal_bit, len);
+ if (ret) {
+ ocfs2_rollback_alloc_dinode_counts(gb_inode, gb_bh, len,
+ le16_to_cpu(gd->bg_chain));
+ mlog_errno(ret);
+ }
+
+ /*
+ * Here we should write the new page out first if we are
+ * in write-back mode.
+ */
+ ret = ocfs2_cow_sync_writeback(inode->i_sb, context->inode, cpos, len);
+ if (ret)
+ mlog_errno(ret);
+
+out_commit:
+ ocfs2_commit_trans(osb, handle);
+ brelse(gd_bh);
+
+out_unlock_tl_inode:
+ mutex_unlock(&tl_inode->i_mutex);
+
+ ocfs2_inode_unlock(gb_inode, 1);
+out_unlock_gb_mutex:
+ mutex_unlock(&gb_inode->i_mutex);
+ brelse(gb_bh);
+ iput(gb_inode);
+
+out:
+ if (context->meta_ac) {
+ ocfs2_free_alloc_context(context->meta_ac);
+ context->meta_ac = NULL;
+ }
+
+ if (ref_tree)
+ ocfs2_unlock_refcount_tree(osb, ref_tree, 1);
+
+ return ret;
+}
+
+/*
+ * Helper to calculate the defraging length in one run according to threshold.
+ */
+static void ocfs2_calc_extent_defrag_len(u32 *alloc_size, u32 *len_defraged,
+ u32 threshold, int *skip)
+{
+ if ((*alloc_size + *len_defraged) < threshold) {
+ /*
+ * proceed defragmentation until we meet the thresh
+ */
+ *len_defraged += *alloc_size;
+ } else if (*len_defraged == 0) {
+ /*
+ * XXX: skip a large extent.
+ */
+ *skip = 1;
+ } else {
+ /*
+ * split this extent to coalesce with former pieces as
+ * to reach the threshold.
+ *
+ * we're done here with one cycle of defragmentation
+ * in a size of 'thresh', resetting 'len_defraged'
+ * forces a new defragmentation.
+ */
+ *alloc_size = threshold - *len_defraged;
+ *len_defraged = 0;
+ }
+}
+
+static int __ocfs2_move_extents_range(struct buffer_head *di_bh,
+ struct ocfs2_move_extents_context *context)
+{
+ int ret = 0, flags, do_defrag, skip = 0;
+ u32 cpos, phys_cpos, move_start, len_to_move, alloc_size;
+ u32 len_defraged = 0, defrag_thresh = 0, new_phys_cpos = 0;
+
+ struct inode *inode = context->inode;
+ struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
+ struct ocfs2_move_extents *range = context->range;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ if ((i_size_read(inode) == 0) || (range->me_len == 0))
+ return 0;
+
+ if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
+ return 0;
+
+ context->refcount_loc = le64_to_cpu(di->i_refcount_loc);
+
+ ocfs2_init_dinode_extent_tree(&context->et, INODE_CACHE(inode), di_bh);
+ ocfs2_init_dealloc_ctxt(&context->dealloc);
+
+ /*
+ * TO-DO XXX:
+ *
+ * - xattr extents.
+ */
+
+ do_defrag = context->auto_defrag;
+
+ /*
+ * extents moving happens in unit of clusters, for the sake
+ * of simplicity, we may ignore two clusters where 'byte_start'
+ * and 'byte_start + len' were within.
+ */
+ move_start = ocfs2_clusters_for_bytes(osb->sb, range->me_start);
+ len_to_move = (range->me_start + range->me_len) >>
+ osb->s_clustersize_bits;
+ if (len_to_move >= move_start)
+ len_to_move -= move_start;
+ else
+ len_to_move = 0;
+
+ if (do_defrag) {
+ defrag_thresh = range->me_threshold >> osb->s_clustersize_bits;
+ if (defrag_thresh <= 1)
+ goto done;
+ } else
+ new_phys_cpos = ocfs2_blocks_to_clusters(inode->i_sb,
+ range->me_goal);
+
+ mlog(0, "Inode: %llu, start: %llu, len: %llu, cstart: %u, clen: %u, "
+ "thresh: %u\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno,
+ (unsigned long long)range->me_start,
+ (unsigned long long)range->me_len,
+ move_start, len_to_move, defrag_thresh);
+
+ cpos = move_start;
+ while (len_to_move) {
+ ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &alloc_size,
+ &flags);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ if (alloc_size > len_to_move)
+ alloc_size = len_to_move;
+
+ /*
+ * XXX: how to deal with a hole:
+ *
+ * - skip the hole of course
+ * - force a new defragmentation
+ */
+ if (!phys_cpos) {
+ if (do_defrag)
+ len_defraged = 0;
+
+ goto next;
+ }
+
+ if (do_defrag) {
+ ocfs2_calc_extent_defrag_len(&alloc_size, &len_defraged,
+ defrag_thresh, &skip);
+ /*
+ * skip large extents
+ */
+ if (skip) {
+ skip = 0;
+ goto next;
+ }
+
+ mlog(0, "#Defrag: cpos: %u, phys_cpos: %u, "
+ "alloc_size: %u, len_defraged: %u\n",
+ cpos, phys_cpos, alloc_size, len_defraged);
+
+ ret = ocfs2_defrag_extent(context, cpos, phys_cpos,
+ &alloc_size, flags);
+ } else {
+ ret = ocfs2_move_extent(context, cpos, phys_cpos,
+ &new_phys_cpos, alloc_size,
+ flags);
+
+ new_phys_cpos += alloc_size;
+ }
+
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ context->clusters_moved += alloc_size;
+next:
+ cpos += alloc_size;
+ len_to_move -= alloc_size;
+ }
+
+done:
+ range->me_flags |= OCFS2_MOVE_EXT_FL_COMPLETE;
+
+out:
+ range->me_moved_len = ocfs2_clusters_to_bytes(osb->sb,
+ context->clusters_moved);
+ range->me_new_offset = ocfs2_clusters_to_bytes(osb->sb,
+ context->new_phys_cpos);
+
+ ocfs2_schedule_truncate_log_flush(osb, 1);
+ ocfs2_run_deallocs(osb, &context->dealloc);
+
+ return ret;
+}
+
+static int ocfs2_move_extents(struct ocfs2_move_extents_context *context)
+{
+ int status;
+ handle_t *handle;
+ struct inode *inode = context->inode;
+ struct ocfs2_dinode *di;
+ struct buffer_head *di_bh = NULL;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb))
+ return -EROFS;
+
+ mutex_lock(&inode->i_mutex);
+
+ /*
+ * This prevents concurrent writes from other nodes
+ */
+ status = ocfs2_rw_lock(inode, 1);
+ if (status) {
+ mlog_errno(status);
+ goto out;
+ }
+
+ status = ocfs2_inode_lock(inode, &di_bh, 1);
+ if (status) {
+ mlog_errno(status);
+ goto out_rw_unlock;
+ }
+
+ /*
+ * rememer ip_xattr_sem also needs to be held if necessary
+ */
+ down_write(&OCFS2_I(inode)->ip_alloc_sem);
+
+ status = __ocfs2_move_extents_range(di_bh, context);
+
+ up_write(&OCFS2_I(inode)->ip_alloc_sem);
+ if (status) {
+ mlog_errno(status);
+ goto out_inode_unlock;
+ }
+
+ /*
+ * We update ctime for these changes
+ */
+ handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
+ if (IS_ERR(handle)) {
+ status = PTR_ERR(handle);
+ mlog_errno(status);
+ goto out_inode_unlock;
+ }
+
+ status = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
+ OCFS2_JOURNAL_ACCESS_WRITE);
+ if (status) {
+ mlog_errno(status);
+ goto out_commit;
+ }
+
+ di = (struct ocfs2_dinode *)di_bh->b_data;
+ inode->i_ctime = CURRENT_TIME;
+ di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
+ di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
+ ocfs2_update_inode_fsync_trans(handle, inode, 0);
+
+ ocfs2_journal_dirty(handle, di_bh);
+
+out_commit:
+ ocfs2_commit_trans(osb, handle);
+
+out_inode_unlock:
+ brelse(di_bh);
+ ocfs2_inode_unlock(inode, 1);
+out_rw_unlock:
+ ocfs2_rw_unlock(inode, 1);
+out:
+ mutex_unlock(&inode->i_mutex);
+
+ return status;
+}
+
+int ocfs2_ioctl_move_extents(struct file *filp, void __user *argp)
+{
+ int status;
+
+ struct inode *inode = file_inode(filp);
+ struct ocfs2_move_extents range;
+ struct ocfs2_move_extents_context *context;
+
+ if (!argp)
+ return -EINVAL;
+
+ status = mnt_want_write_file(filp);
+ if (status)
+ return status;
+
+ if ((!S_ISREG(inode->i_mode)) || !(filp->f_mode & FMODE_WRITE)) {
+ status = -EPERM;
+ goto out_drop;
+ }
+
+ if (inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
+ status = -EPERM;
+ goto out_drop;
+ }
+
+ context = kzalloc(sizeof(struct ocfs2_move_extents_context), GFP_NOFS);
+ if (!context) {
+ status = -ENOMEM;
+ mlog_errno(status);
+ goto out_drop;
+ }
+
+ context->inode = inode;
+ context->file = filp;
+
+ if (copy_from_user(&range, argp, sizeof(range))) {
+ status = -EFAULT;
+ goto out_free;
+ }
+
+ if (range.me_start > i_size_read(inode)) {
+ status = -EINVAL;
+ goto out_free;
+ }
+
+ if (range.me_start + range.me_len > i_size_read(inode))
+ range.me_len = i_size_read(inode) - range.me_start;
+
+ context->range = &range;
+
+ if (range.me_flags & OCFS2_MOVE_EXT_FL_AUTO_DEFRAG) {
+ context->auto_defrag = 1;
+ /*
+ * ok, the default theshold for the defragmentation
+ * is 1M, since our maximum clustersize was 1M also.
+ * any thought?
+ */
+ if (!range.me_threshold)
+ range.me_threshold = 1024 * 1024;
+
+ if (range.me_threshold > i_size_read(inode))
+ range.me_threshold = i_size_read(inode);
+
+ if (range.me_flags & OCFS2_MOVE_EXT_FL_PART_DEFRAG)
+ context->partial = 1;
+ } else {
+ /*
+ * first best-effort attempt to validate and adjust the goal
+ * (physical address in block), while it can't guarantee later
+ * operation can succeed all the time since global_bitmap may
+ * change a bit over time.
+ */
+
+ status = ocfs2_validate_and_adjust_move_goal(inode, &range);
+ if (status)
+ goto out_copy;
+ }
+
+ status = ocfs2_move_extents(context);
+ if (status)
+ mlog_errno(status);
+out_copy:
+ /*
+ * movement/defragmentation may end up being partially completed,
+ * that's the reason why we need to return userspace the finished
+ * length and new_offset even if failure happens somewhere.
+ */
+ if (copy_to_user(argp, &range, sizeof(range)))
+ status = -EFAULT;
+
+out_free:
+ kfree(context);
+out_drop:
+ mnt_drop_write_file(filp);
+
+ return status;
+}