*
* extent_map.c
*
- * In-memory extent map for OCFS2. Man, this code was prettier in
- * the library.
+ * Block/Cluster mapping functions
*
* Copyright (C) 2004 Oracle. All rights reserved.
*
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/types.h>
-#include <linux/slab.h>
-#include <linux/rbtree.h>
#define MLOG_MASK_PREFIX ML_EXTENT_MAP
#include <cluster/masklog.h>
#include "ocfs2.h"
+#include "alloc.h"
#include "extent_map.h"
#include "inode.h"
#include "super.h"
#include "buffer_head_io.h"
-
-/*
- * SUCK SUCK SUCK
- * Our headers are so bad that struct ocfs2_extent_map is in ocfs.h
- */
-
-struct ocfs2_extent_map_entry {
- struct rb_node e_node;
- int e_tree_depth;
- struct ocfs2_extent_rec e_rec;
-};
-
-struct ocfs2_em_insert_context {
- int need_left;
- int need_right;
- struct ocfs2_extent_map_entry *new_ent;
- struct ocfs2_extent_map_entry *old_ent;
- struct ocfs2_extent_map_entry *left_ent;
- struct ocfs2_extent_map_entry *right_ent;
-};
-
-static struct kmem_cache *ocfs2_em_ent_cachep = NULL;
-
-
-static struct ocfs2_extent_map_entry *
-ocfs2_extent_map_lookup(struct ocfs2_extent_map *em,
- u32 cpos, u32 clusters,
- struct rb_node ***ret_p,
- struct rb_node **ret_parent);
-static int ocfs2_extent_map_insert(struct inode *inode,
- struct ocfs2_extent_rec *rec,
- int tree_depth);
-static int ocfs2_extent_map_insert_entry(struct ocfs2_extent_map *em,
- struct ocfs2_extent_map_entry *ent);
-static int ocfs2_extent_map_find_leaf(struct inode *inode,
- u32 cpos, u32 clusters,
- struct ocfs2_extent_list *el);
-static int ocfs2_extent_map_lookup_read(struct inode *inode,
- u32 cpos, u32 clusters,
- struct ocfs2_extent_map_entry **ret_ent);
-static int ocfs2_extent_map_try_insert(struct inode *inode,
- struct ocfs2_extent_rec *rec,
- int tree_depth,
- struct ocfs2_em_insert_context *ctxt);
-
-/* returns 1 only if the rec contains all the given clusters -- that is that
- * rec's cpos is <= the cluster cpos and that the rec endpoint (cpos +
- * clusters) is >= the argument's endpoint */
-static int ocfs2_extent_rec_contains_clusters(struct ocfs2_extent_rec *rec,
- u32 cpos, u32 clusters)
-{
- if (le32_to_cpu(rec->e_cpos) > cpos)
- return 0;
- if (cpos + clusters > le32_to_cpu(rec->e_cpos) +
- le32_to_cpu(rec->e_clusters))
- return 0;
- return 1;
-}
-
-
/*
- * Find an entry in the tree that intersects the region passed in.
- * Note that this will find straddled intervals, it is up to the
- * callers to enforce any boundary conditions.
- *
- * Callers must hold ip_lock. This lookup is not guaranteed to return
- * a tree_depth 0 match, and as such can race inserts if the lock
- * were not held.
+ * Return the index of the extent record which contains cluster #v_cluster.
+ * -1 is returned if it was not found.
*
- * The rb_node garbage lets insertion share the search. Trivial
- * callers pass NULL.
+ * Should work fine on interior and exterior nodes.
*/
-static struct ocfs2_extent_map_entry *
-ocfs2_extent_map_lookup(struct ocfs2_extent_map *em,
- u32 cpos, u32 clusters,
- struct rb_node ***ret_p,
- struct rb_node **ret_parent)
+static int ocfs2_search_extent_list(struct ocfs2_extent_list *el,
+ u32 v_cluster)
{
- struct rb_node **p = &em->em_extents.rb_node;
- struct rb_node *parent = NULL;
- struct ocfs2_extent_map_entry *ent = NULL;
-
- while (*p)
- {
- parent = *p;
- ent = rb_entry(parent, struct ocfs2_extent_map_entry,
- e_node);
- if ((cpos + clusters) <= le32_to_cpu(ent->e_rec.e_cpos)) {
- p = &(*p)->rb_left;
- ent = NULL;
- } else if (cpos >= (le32_to_cpu(ent->e_rec.e_cpos) +
- le32_to_cpu(ent->e_rec.e_clusters))) {
- p = &(*p)->rb_right;
- ent = NULL;
- } else
- break;
- }
-
- if (ret_p != NULL)
- *ret_p = p;
- if (ret_parent != NULL)
- *ret_parent = parent;
- return ent;
-}
-
-/*
- * Find the leaf containing the interval we want. While we're on our
- * way down the tree, fill in every record we see at any depth, because
- * we might want it later.
- *
- * Note that this code is run without ip_lock. That's because it
- * sleeps while reading. If someone is also filling the extent list at
- * the same time we are, we might have to restart.
- */
-static int ocfs2_extent_map_find_leaf(struct inode *inode,
- u32 cpos, u32 clusters,
- struct ocfs2_extent_list *el)
-{
- int i, ret;
- struct buffer_head *eb_bh = NULL;
- u64 blkno;
- u32 rec_end;
- struct ocfs2_extent_block *eb;
+ int ret = -1;
+ int i;
struct ocfs2_extent_rec *rec;
+ u32 rec_end, rec_start;
- /*
- * The bh data containing the el cannot change here, because
- * we hold alloc_sem. So we can do this without other
- * locks.
- */
- while (el->l_tree_depth)
- {
- blkno = 0;
- for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
- rec = &el->l_recs[i];
- rec_end = (le32_to_cpu(rec->e_cpos) +
- le32_to_cpu(rec->e_clusters));
-
- ret = -EBADR;
- if (rec_end > OCFS2_I(inode)->ip_clusters) {
- mlog_errno(ret);
- ocfs2_error(inode->i_sb,
- "Extent %d at e_blkno %llu of inode %llu goes past ip_clusters of %u\n",
- i,
- (unsigned long long)le64_to_cpu(rec->e_blkno),
- (unsigned long long)OCFS2_I(inode)->ip_blkno,
- OCFS2_I(inode)->ip_clusters);
- goto out_free;
- }
-
- if (rec_end <= cpos) {
- ret = ocfs2_extent_map_insert(inode, rec,
- le16_to_cpu(el->l_tree_depth));
- if (ret && (ret != -EEXIST)) {
- mlog_errno(ret);
- goto out_free;
- }
- continue;
- }
- if ((cpos + clusters) <= le32_to_cpu(rec->e_cpos)) {
- ret = ocfs2_extent_map_insert(inode, rec,
- le16_to_cpu(el->l_tree_depth));
- if (ret && (ret != -EEXIST)) {
- mlog_errno(ret);
- goto out_free;
- }
- continue;
- }
-
- /*
- * We've found a record that matches our
- * interval. We don't insert it because we're
- * about to traverse it.
- */
-
- /* Check to see if we're stradling */
- ret = -ESRCH;
- if (!ocfs2_extent_rec_contains_clusters(rec,
- cpos,
- clusters)) {
- mlog_errno(ret);
- goto out_free;
- }
-
- /*
- * If we've already found a record, the el has
- * two records covering the same interval.
- * EEEK!
- */
- ret = -EBADR;
- if (blkno) {
- mlog_errno(ret);
- ocfs2_error(inode->i_sb,
- "Multiple extents for (cpos = %u, clusters = %u) on inode %llu; e_blkno %llu and rec %d at e_blkno %llu\n",
- cpos, clusters,
- (unsigned long long)OCFS2_I(inode)->ip_blkno,
- (unsigned long long)blkno, i,
- (unsigned long long)le64_to_cpu(rec->e_blkno));
- goto out_free;
- }
-
- blkno = le64_to_cpu(rec->e_blkno);
- }
-
- /*
- * We don't support holes, and we're still up
- * in the branches, so we'd better have found someone
- */
- ret = -EBADR;
- if (!blkno) {
- ocfs2_error(inode->i_sb,
- "No record found for (cpos = %u, clusters = %u) on inode %llu\n",
- cpos, clusters,
- (unsigned long long)OCFS2_I(inode)->ip_blkno);
- mlog_errno(ret);
- goto out_free;
- }
-
- if (eb_bh) {
- brelse(eb_bh);
- eb_bh = NULL;
- }
- ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
- blkno, &eb_bh, OCFS2_BH_CACHED,
- inode);
- if (ret) {
- mlog_errno(ret);
- goto out_free;
- }
- eb = (struct ocfs2_extent_block *)eb_bh->b_data;
- if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
- OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
- ret = -EIO;
- goto out_free;
- }
- el = &eb->h_list;
- }
-
- BUG_ON(el->l_tree_depth);
-
- for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
+ for(i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) {
rec = &el->l_recs[i];
- if ((le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters)) >
- OCFS2_I(inode)->ip_clusters) {
- ret = -EBADR;
- mlog_errno(ret);
- ocfs2_error(inode->i_sb,
- "Extent %d at e_blkno %llu of inode %llu goes past ip_clusters of %u\n",
- i,
- (unsigned long long)le64_to_cpu(rec->e_blkno),
- (unsigned long long)OCFS2_I(inode)->ip_blkno,
- OCFS2_I(inode)->ip_clusters);
- return ret;
- }
+ rec_start = le32_to_cpu(rec->e_cpos);
+ rec_end = rec_start + le32_to_cpu(rec->e_clusters);
- ret = ocfs2_extent_map_insert(inode, rec,
- le16_to_cpu(el->l_tree_depth));
- if (ret && (ret != -EEXIST)) {
- mlog_errno(ret);
- goto out_free;
+ if (v_cluster >= rec_start && v_cluster < rec_end) {
+ ret = i;
+ break;
}
}
- ret = 0;
-
-out_free:
- if (eb_bh)
- brelse(eb_bh);
-
return ret;
}
-/*
- * This lookup actually will read from disk. It has one invariant:
- * It will never re-traverse blocks. This means that all inserts should
- * be new regions or more granular regions (both allowed by insert).
- */
-static int ocfs2_extent_map_lookup_read(struct inode *inode,
- u32 cpos,
- u32 clusters,
- struct ocfs2_extent_map_entry **ret_ent)
+static int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
+ u32 *p_cluster, u32 *num_clusters)
{
- int ret;
- u64 blkno;
- struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
- struct ocfs2_extent_map_entry *ent;
- struct buffer_head *bh = NULL;
- struct ocfs2_extent_block *eb;
+ int ret, i;
+ struct buffer_head *di_bh = NULL;
+ struct buffer_head *eb_bh = NULL;
struct ocfs2_dinode *di;
+ struct ocfs2_extent_block *eb;
struct ocfs2_extent_list *el;
+ struct ocfs2_extent_rec *rec;
+ u32 coff;
- spin_lock(&OCFS2_I(inode)->ip_lock);
- ent = ocfs2_extent_map_lookup(em, cpos, clusters, NULL, NULL);
- if (ent) {
- if (!ent->e_tree_depth) {
- spin_unlock(&OCFS2_I(inode)->ip_lock);
- *ret_ent = ent;
- return 0;
- }
- blkno = le64_to_cpu(ent->e_rec.e_blkno);
- spin_unlock(&OCFS2_I(inode)->ip_lock);
-
- ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), blkno, &bh,
- OCFS2_BH_CACHED, inode);
- if (ret) {
- mlog_errno(ret);
- if (bh)
- brelse(bh);
- return ret;
- }
- 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);
- brelse(bh);
- return -EIO;
- }
- el = &eb->h_list;
- } else {
- spin_unlock(&OCFS2_I(inode)->ip_lock);
-
- ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
- OCFS2_I(inode)->ip_blkno, &bh,
- OCFS2_BH_CACHED, inode);
- if (ret) {
- mlog_errno(ret);
- if (bh)
- brelse(bh);
- return ret;
- }
- di = (struct ocfs2_dinode *)bh->b_data;
- if (!OCFS2_IS_VALID_DINODE(di)) {
- brelse(bh);
- OCFS2_RO_ON_INVALID_DINODE(inode->i_sb, di);
- return -EIO;
- }
- el = &di->id2.i_list;
- }
-
- ret = ocfs2_extent_map_find_leaf(inode, cpos, clusters, el);
- brelse(bh);
+ ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), OCFS2_I(inode)->ip_blkno,
+ &di_bh, OCFS2_BH_CACHED, inode);
if (ret) {
mlog_errno(ret);
- return ret;
+ goto out;
}
- ent = ocfs2_extent_map_lookup(em, cpos, clusters, NULL, NULL);
- if (!ent) {
- ret = -ESRCH;
- mlog_errno(ret);
- return ret;
- }
-
- /* FIXME: Make sure this isn't a corruption */
- BUG_ON(ent->e_tree_depth);
+ di = (struct ocfs2_dinode *) di_bh->b_data;
+ el = &di->id2.i_list;
- *ret_ent = ent;
-
- return 0;
-}
-
-/*
- * Callers must hold ip_lock. This can insert pieces of the tree,
- * thus racing lookup if the lock weren't held.
- */
-static int ocfs2_extent_map_insert_entry(struct ocfs2_extent_map *em,
- struct ocfs2_extent_map_entry *ent)
-{
- struct rb_node **p, *parent;
- struct ocfs2_extent_map_entry *old_ent;
-
- old_ent = ocfs2_extent_map_lookup(em, le32_to_cpu(ent->e_rec.e_cpos),
- le32_to_cpu(ent->e_rec.e_clusters),
- &p, &parent);
- if (old_ent)
- return -EEXIST;
-
- rb_link_node(&ent->e_node, parent, p);
- rb_insert_color(&ent->e_node, &em->em_extents);
-
- return 0;
-}
-
-
-/*
- * Simple rule: on any return code other than -EAGAIN, anything left
- * in the insert_context will be freed.
- *
- * Simple rule #2: A return code of -EEXIST from this function or
- * its calls to ocfs2_extent_map_insert_entry() signifies that another
- * thread beat us to the insert. It is not an actual error, but it
- * tells the caller we have no more work to do.
- */
-static int ocfs2_extent_map_try_insert(struct inode *inode,
- struct ocfs2_extent_rec *rec,
- int tree_depth,
- struct ocfs2_em_insert_context *ctxt)
-{
- int ret;
- struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
- struct ocfs2_extent_map_entry *old_ent;
-
- ctxt->need_left = 0;
- ctxt->need_right = 0;
- ctxt->old_ent = NULL;
-
- spin_lock(&OCFS2_I(inode)->ip_lock);
- ret = ocfs2_extent_map_insert_entry(em, ctxt->new_ent);
- if (!ret) {
- ctxt->new_ent = NULL;
- goto out_unlock;
- }
-
- /* Since insert_entry failed, the map MUST have old_ent */
- old_ent = ocfs2_extent_map_lookup(em, le32_to_cpu(rec->e_cpos),
- le32_to_cpu(rec->e_clusters),
- NULL, NULL);
-
- BUG_ON(!old_ent);
+ if (el->l_tree_depth) {
+ ret = ocfs2_find_leaf(inode, el, v_cluster, &eb_bh);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
- if (old_ent->e_tree_depth < tree_depth) {
- /* Another thread beat us to the lower tree_depth */
- ret = -EEXIST;
- goto out_unlock;
+ eb = (struct ocfs2_extent_block *) eb_bh->b_data;
+ el = &eb->h_list;
}
- if (old_ent->e_tree_depth == tree_depth) {
+ i = ocfs2_search_extent_list(el, v_cluster);
+ if (i == -1) {
/*
- * Another thread beat us to this tree_depth.
- * Let's make sure we agree with that thread (the
- * extent_rec should be identical).
+ * A hole was found. Return some canned values that
+ * callers can key on.
*/
- if (!memcmp(rec, &old_ent->e_rec,
- sizeof(struct ocfs2_extent_rec)))
- ret = 0;
- else
- /* FIXME: Should this be ESRCH/EBADR??? */
- ret = -EEXIST;
+ *p_cluster = 0;
+ if (num_clusters)
+ *num_clusters = 1;
+ } else {
+ rec = &el->l_recs[i];
- goto out_unlock;
- }
+ BUG_ON(v_cluster < le32_to_cpu(rec->e_cpos));
- /*
- * We do it in this order specifically so that no actual tree
- * changes occur until we have all the pieces we need. We
- * don't want malloc failures to leave an inconsistent tree.
- * Whenever we drop the lock, another process could be
- * inserting. Also note that, if another process just beat us
- * to an insert, we might not need the same pieces we needed
- * the first go round. In the end, the pieces we need will
- * be used, and the pieces we don't will be freed.
- */
- ctxt->need_left = !!(le32_to_cpu(rec->e_cpos) >
- le32_to_cpu(old_ent->e_rec.e_cpos));
- ctxt->need_right = !!((le32_to_cpu(old_ent->e_rec.e_cpos) +
- le32_to_cpu(old_ent->e_rec.e_clusters)) >
- (le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters)));
- ret = -EAGAIN;
- if (ctxt->need_left) {
- if (!ctxt->left_ent)
- goto out_unlock;
- *(ctxt->left_ent) = *old_ent;
- ctxt->left_ent->e_rec.e_clusters =
- cpu_to_le32(le32_to_cpu(rec->e_cpos) -
- le32_to_cpu(ctxt->left_ent->e_rec.e_cpos));
- }
- if (ctxt->need_right) {
- if (!ctxt->right_ent)
- goto out_unlock;
- *(ctxt->right_ent) = *old_ent;
- ctxt->right_ent->e_rec.e_cpos =
- cpu_to_le32(le32_to_cpu(rec->e_cpos) +
+ if (!rec->e_blkno) {
+ ocfs2_error(inode->i_sb, "Inode %lu has bad extent "
+ "record (%u, %u, 0)", inode->i_ino,
+ le32_to_cpu(rec->e_cpos),
le32_to_cpu(rec->e_clusters));
- ctxt->right_ent->e_rec.e_clusters =
- cpu_to_le32((le32_to_cpu(old_ent->e_rec.e_cpos) +
- le32_to_cpu(old_ent->e_rec.e_clusters)) -
- le32_to_cpu(ctxt->right_ent->e_rec.e_cpos));
- }
-
- rb_erase(&old_ent->e_node, &em->em_extents);
- /* Now that he's erased, set him up for deletion */
- ctxt->old_ent = old_ent;
-
- if (ctxt->need_left) {
- ret = ocfs2_extent_map_insert_entry(em,
- ctxt->left_ent);
- if (ret)
- goto out_unlock;
- ctxt->left_ent = NULL;
- }
-
- if (ctxt->need_right) {
- ret = ocfs2_extent_map_insert_entry(em,
- ctxt->right_ent);
- if (ret)
- goto out_unlock;
- ctxt->right_ent = NULL;
- }
-
- ret = ocfs2_extent_map_insert_entry(em, ctxt->new_ent);
-
- if (!ret)
- ctxt->new_ent = NULL;
-
-out_unlock:
- spin_unlock(&OCFS2_I(inode)->ip_lock);
-
- return ret;
-}
-
-
-static int ocfs2_extent_map_insert(struct inode *inode,
- struct ocfs2_extent_rec *rec,
- int tree_depth)
-{
- int ret;
- struct ocfs2_em_insert_context ctxt = {0, };
-
- if ((le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters)) >
- OCFS2_I(inode)->ip_map.em_clusters) {
- ret = -EBADR;
- mlog_errno(ret);
- return ret;
- }
-
- /* Zero e_clusters means a truncated tail record. It better be EOF */
- if (!rec->e_clusters) {
- if ((le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters)) !=
- OCFS2_I(inode)->ip_map.em_clusters) {
- ret = -EBADR;
- mlog_errno(ret);
- ocfs2_error(inode->i_sb,
- "Zero e_clusters on non-tail extent record at e_blkno %llu on inode %llu\n",
- (unsigned long long)le64_to_cpu(rec->e_blkno),
- (unsigned long long)OCFS2_I(inode)->ip_blkno);
- return ret;
- }
-
- /* Ignore the truncated tail */
- return 0;
- }
-
- ret = -ENOMEM;
- ctxt.new_ent = kmem_cache_alloc(ocfs2_em_ent_cachep,
- GFP_NOFS);
- if (!ctxt.new_ent) {
- mlog_errno(ret);
- return ret;
- }
-
- ctxt.new_ent->e_rec = *rec;
- ctxt.new_ent->e_tree_depth = tree_depth;
-
- do {
- ret = -ENOMEM;
- if (ctxt.need_left && !ctxt.left_ent) {
- ctxt.left_ent =
- kmem_cache_alloc(ocfs2_em_ent_cachep,
- GFP_NOFS);
- if (!ctxt.left_ent)
- break;
- }
- if (ctxt.need_right && !ctxt.right_ent) {
- ctxt.right_ent =
- kmem_cache_alloc(ocfs2_em_ent_cachep,
- GFP_NOFS);
- if (!ctxt.right_ent)
- break;
+ ret = -EROFS;
+ goto out;
}
- ret = ocfs2_extent_map_try_insert(inode, rec,
- tree_depth, &ctxt);
- } while (ret == -EAGAIN);
+ coff = v_cluster - le32_to_cpu(rec->e_cpos);
- if ((ret < 0) && (ret != -EEXIST))
- mlog_errno(ret);
-
- if (ctxt.left_ent)
- kmem_cache_free(ocfs2_em_ent_cachep, ctxt.left_ent);
- if (ctxt.right_ent)
- kmem_cache_free(ocfs2_em_ent_cachep, ctxt.right_ent);
- if (ctxt.old_ent)
- kmem_cache_free(ocfs2_em_ent_cachep, ctxt.old_ent);
- if (ctxt.new_ent)
- kmem_cache_free(ocfs2_em_ent_cachep, ctxt.new_ent);
-
- return ret;
-}
+ *p_cluster = ocfs2_blocks_to_clusters(inode->i_sb,
+ le64_to_cpu(rec->e_blkno));
+ *p_cluster = *p_cluster + coff;
-/*
- * Append this record to the tail of the extent map. It must be
- * tree_depth 0. The record might be an extension of an existing
- * record, and as such that needs to be handled. eg:
- *
- * Existing record in the extent map:
- *
- * cpos = 10, len = 10
- * |---------|
- *
- * New Record:
- *
- * cpos = 10, len = 20
- * |------------------|
- *
- * The passed record is the new on-disk record. The new_clusters value
- * is how many clusters were added to the file. If the append is a
- * contiguous append, the new_clusters has been added to
- * rec->e_clusters. If the append is an entirely new extent, then
- * rec->e_clusters is == new_clusters.
- */
-int ocfs2_extent_map_append(struct inode *inode,
- struct ocfs2_extent_rec *rec,
- u32 new_clusters)
-{
- int ret;
- struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
- struct ocfs2_extent_map_entry *ent;
- struct ocfs2_extent_rec *old;
-
- BUG_ON(!new_clusters);
- BUG_ON(le32_to_cpu(rec->e_clusters) < new_clusters);
-
- if (em->em_clusters < OCFS2_I(inode)->ip_clusters) {
- /*
- * Size changed underneath us on disk. Drop any
- * straddling records and update our idea of
- * i_clusters
- */
- ocfs2_extent_map_drop(inode, em->em_clusters - 1);
- em->em_clusters = OCFS2_I(inode)->ip_clusters;
+ if (num_clusters)
+ *num_clusters = le32_to_cpu(rec->e_clusters) - coff;
}
- mlog_bug_on_msg((le32_to_cpu(rec->e_cpos) +
- le32_to_cpu(rec->e_clusters)) !=
- (em->em_clusters + new_clusters),
- "Inode %llu:\n"
- "rec->e_cpos = %u + rec->e_clusters = %u = %u\n"
- "em->em_clusters = %u + new_clusters = %u = %u\n",
- (unsigned long long)OCFS2_I(inode)->ip_blkno,
- le32_to_cpu(rec->e_cpos), le32_to_cpu(rec->e_clusters),
- le32_to_cpu(rec->e_cpos) + le32_to_cpu(rec->e_clusters),
- em->em_clusters, new_clusters,
- em->em_clusters + new_clusters);
-
- em->em_clusters += new_clusters;
-
- ret = -ENOENT;
- if (le32_to_cpu(rec->e_clusters) > new_clusters) {
- /* This is a contiguous append */
- ent = ocfs2_extent_map_lookup(em, le32_to_cpu(rec->e_cpos), 1,
- NULL, NULL);
- if (ent) {
- old = &ent->e_rec;
- BUG_ON((le32_to_cpu(rec->e_cpos) +
- le32_to_cpu(rec->e_clusters)) !=
- (le32_to_cpu(old->e_cpos) +
- le32_to_cpu(old->e_clusters) +
- new_clusters));
- if (ent->e_tree_depth == 0) {
- BUG_ON(le32_to_cpu(old->e_cpos) !=
- le32_to_cpu(rec->e_cpos));
- BUG_ON(le64_to_cpu(old->e_blkno) !=
- le64_to_cpu(rec->e_blkno));
- ret = 0;
- }
- /*
- * Let non-leafs fall through as -ENOENT to
- * force insertion of the new leaf.
- */
- le32_add_cpu(&old->e_clusters, new_clusters);
- }
- }
-
- if (ret == -ENOENT)
- ret = ocfs2_extent_map_insert(inode, rec, 0);
- if (ret < 0)
- mlog_errno(ret);
+out:
+ brelse(di_bh);
+ brelse(eb_bh);
return ret;
}
-#if 0
-/* Code here is included but defined out as it completes the extent
- * map api and may be used in the future. */
-
/*
- * Look up the record containing this cluster offset. This record is
- * part of the extent map. Do not free it. Any changes you make to
- * it will reflect in the extent map. So, if your last extent
- * is (cpos = 10, clusters = 10) and you truncate the file by 5
- * clusters, you can do:
- *
- * ret = ocfs2_extent_map_get_rec(em, orig_size - 5, &rec);
- * rec->e_clusters -= 5;
- *
- * The lookup does not read from disk. If the map isn't filled in for
- * an entry, you won't find it.
- *
- * Also note that the returned record is valid until alloc_sem is
- * dropped. After that, truncate and extend can happen. Caveat Emptor.
+ * This expects alloc_sem to be held. The allocation cannot change at
+ * all while the map is in the process of being updated.
*/
-int ocfs2_extent_map_get_rec(struct inode *inode, u32 cpos,
- struct ocfs2_extent_rec **rec,
- int *tree_depth)
-{
- int ret = -ENOENT;
- struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
- struct ocfs2_extent_map_entry *ent;
-
- *rec = NULL;
-
- if (cpos >= OCFS2_I(inode)->ip_clusters)
- return -EINVAL;
-
- if (cpos >= em->em_clusters) {
- /*
- * Size changed underneath us on disk. Drop any
- * straddling records and update our idea of
- * i_clusters
- */
- ocfs2_extent_map_drop(inode, em->em_clusters - 1);
- em->em_clusters = OCFS2_I(inode)->ip_clusters ;
- }
-
- ent = ocfs2_extent_map_lookup(&OCFS2_I(inode)->ip_map, cpos, 1,
- NULL, NULL);
-
- if (ent) {
- *rec = &ent->e_rec;
- if (tree_depth)
- *tree_depth = ent->e_tree_depth;
- ret = 0;
- }
-
- return ret;
-}
-
-int ocfs2_extent_map_get_clusters(struct inode *inode,
- u32 v_cpos, int count,
- u32 *p_cpos, int *ret_count)
-{
- int ret;
- u32 coff, ccount;
- struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
- struct ocfs2_extent_map_entry *ent = NULL;
-
- *p_cpos = ccount = 0;
-
- if ((v_cpos + count) > OCFS2_I(inode)->ip_clusters)
- return -EINVAL;
-
- if ((v_cpos + count) > em->em_clusters) {
- /*
- * Size changed underneath us on disk. Drop any
- * straddling records and update our idea of
- * i_clusters
- */
- ocfs2_extent_map_drop(inode, em->em_clusters - 1);
- em->em_clusters = OCFS2_I(inode)->ip_clusters;
- }
-
-
- ret = ocfs2_extent_map_lookup_read(inode, v_cpos, count, &ent);
- if (ret)
- return ret;
-
- if (ent) {
- /* We should never find ourselves straddling an interval */
- if (!ocfs2_extent_rec_contains_clusters(&ent->e_rec,
- v_cpos,
- count))
- return -ESRCH;
-
- coff = v_cpos - le32_to_cpu(ent->e_rec.e_cpos);
- *p_cpos = ocfs2_blocks_to_clusters(inode->i_sb,
- le64_to_cpu(ent->e_rec.e_blkno)) +
- coff;
-
- if (ret_count)
- *ret_count = le32_to_cpu(ent->e_rec.e_clusters) - coff;
-
- return 0;
- }
-
-
- return -ENOENT;
-}
-
-#endif /* 0 */
-
-int ocfs2_extent_map_get_blocks(struct inode *inode,
- u64 v_blkno, int count,
- u64 *p_blkno, int *ret_count)
+int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
+ int *ret_count)
{
int ret;
- u64 boff;
- u32 cpos, clusters;
int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
- struct ocfs2_extent_map_entry *ent = NULL;
- struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
- struct ocfs2_extent_rec *rec;
-
- *p_blkno = 0;
+ u32 cpos, num_clusters, p_cluster;
+ u64 boff = 0;
cpos = ocfs2_blocks_to_clusters(inode->i_sb, v_blkno);
- clusters = ocfs2_blocks_to_clusters(inode->i_sb,
- (u64)count + bpc - 1);
- if ((cpos + clusters) > OCFS2_I(inode)->ip_clusters) {
- ret = -EINVAL;
- mlog_errno(ret);
- return ret;
- }
- if ((cpos + clusters) > em->em_clusters) {
- /*
- * Size changed underneath us on disk. Drop any
- * straddling records and update our idea of
- * i_clusters
- */
- ocfs2_extent_map_drop(inode, em->em_clusters - 1);
- em->em_clusters = OCFS2_I(inode)->ip_clusters;
- }
-
- ret = ocfs2_extent_map_lookup_read(inode, cpos, clusters, &ent);
+ ret = ocfs2_get_clusters(inode, cpos, &p_cluster, &num_clusters);
if (ret) {
mlog_errno(ret);
- return ret;
+ goto out;
}
- if (ent)
- {
- rec = &ent->e_rec;
-
- /* We should never find ourselves straddling an interval */
- if (!ocfs2_extent_rec_contains_clusters(rec, cpos, clusters)) {
- ret = -ESRCH;
- mlog_errno(ret);
- return ret;
- }
-
- boff = ocfs2_clusters_to_blocks(inode->i_sb, cpos -
- le32_to_cpu(rec->e_cpos));
+ /*
+ * p_cluster == 0 indicates a hole.
+ */
+ if (p_cluster) {
+ boff = ocfs2_clusters_to_blocks(inode->i_sb, p_cluster);
boff += (v_blkno & (u64)(bpc - 1));
- *p_blkno = le64_to_cpu(rec->e_blkno) + boff;
-
- if (ret_count) {
- *ret_count = ocfs2_clusters_to_blocks(inode->i_sb,
- le32_to_cpu(rec->e_clusters)) - boff;
- }
-
- return 0;
}
- return -ENOENT;
-}
-
-int ocfs2_extent_map_init(struct inode *inode)
-{
- struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
+ *p_blkno = boff;
- em->em_extents = RB_ROOT;
- em->em_clusters = 0;
-
- return 0;
-}
-
-/* Needs the lock */
-static void __ocfs2_extent_map_drop(struct inode *inode,
- u32 new_clusters,
- struct rb_node **free_head,
- struct ocfs2_extent_map_entry **tail_ent)
-{
- struct rb_node *node, *next;
- struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
- struct ocfs2_extent_map_entry *ent;
-
- *free_head = NULL;
-
- ent = NULL;
- node = rb_last(&em->em_extents);
- while (node)
- {
- next = rb_prev(node);
-
- ent = rb_entry(node, struct ocfs2_extent_map_entry,
- e_node);
- if (le32_to_cpu(ent->e_rec.e_cpos) < new_clusters)
- break;
-
- rb_erase(&ent->e_node, &em->em_extents);
-
- node->rb_right = *free_head;
- *free_head = node;
-
- ent = NULL;
- node = next;
- }
-
- /* Do we have an entry straddling new_clusters? */
- if (tail_ent) {
- if (ent &&
- ((le32_to_cpu(ent->e_rec.e_cpos) +
- le32_to_cpu(ent->e_rec.e_clusters)) > new_clusters))
- *tail_ent = ent;
- else
- *tail_ent = NULL;
+ if (ret_count) {
+ *ret_count = ocfs2_clusters_to_blocks(inode->i_sb, num_clusters);
+ *ret_count -= v_blkno & (u64)(bpc - 1);
}
-}
-
-static void __ocfs2_extent_map_drop_cleanup(struct rb_node *free_head)
-{
- struct rb_node *node;
- struct ocfs2_extent_map_entry *ent;
-
- while (free_head) {
- node = free_head;
- free_head = node->rb_right;
- ent = rb_entry(node, struct ocfs2_extent_map_entry,
- e_node);
- kmem_cache_free(ocfs2_em_ent_cachep, ent);
- }
-}
-
-/*
- * Remove all entries past new_clusters, inclusive of an entry that
- * contains new_clusters. This is effectively a cache forget.
- *
- * If you want to also clip the last extent by some number of clusters,
- * you need to call ocfs2_extent_map_trunc().
- * This code does not check or modify ip_clusters.
- */
-int ocfs2_extent_map_drop(struct inode *inode, u32 new_clusters)
-{
- struct rb_node *free_head = NULL;
- struct ocfs2_extent_map *em = &OCFS2_I(inode)->ip_map;
- struct ocfs2_extent_map_entry *ent;
-
- spin_lock(&OCFS2_I(inode)->ip_lock);
-
- __ocfs2_extent_map_drop(inode, new_clusters, &free_head, &ent);
-
- if (ent) {
- rb_erase(&ent->e_node, &em->em_extents);
- ent->e_node.rb_right = free_head;
- free_head = &ent->e_node;
- }
-
- spin_unlock(&OCFS2_I(inode)->ip_lock);
-
- if (free_head)
- __ocfs2_extent_map_drop_cleanup(free_head);
-
- return 0;
-}
-
-/*
- * Remove all entries past new_clusters and also clip any extent
- * straddling new_clusters, if there is one. This does not check
- * or modify ip_clusters
- */
-int ocfs2_extent_map_trunc(struct inode *inode, u32 new_clusters)
-{
- struct rb_node *free_head = NULL;
- struct ocfs2_extent_map_entry *ent = NULL;
-
- spin_lock(&OCFS2_I(inode)->ip_lock);
-
- __ocfs2_extent_map_drop(inode, new_clusters, &free_head, &ent);
-
- if (ent)
- ent->e_rec.e_clusters = cpu_to_le32(new_clusters -
- le32_to_cpu(ent->e_rec.e_cpos));
-
- OCFS2_I(inode)->ip_map.em_clusters = new_clusters;
-
- spin_unlock(&OCFS2_I(inode)->ip_lock);
-
- if (free_head)
- __ocfs2_extent_map_drop_cleanup(free_head);
-
- return 0;
-}
-
-int __init init_ocfs2_extent_maps(void)
-{
- ocfs2_em_ent_cachep =
- kmem_cache_create("ocfs2_em_ent",
- sizeof(struct ocfs2_extent_map_entry),
- 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
- if (!ocfs2_em_ent_cachep)
- return -ENOMEM;
-
- return 0;
-}
-
-void exit_ocfs2_extent_maps(void)
-{
- kmem_cache_destroy(ocfs2_em_ent_cachep);
+out:
+ return ret;
}
projects / linux-2.6 / commitdiff