#include "buffer_head_io.h"
/*
- * Return the index of the extent record which contains cluster #v_cluster.
- * -1 is returned if it was not found.
+ * The extent caching implementation is intentionally trivial.
*
- * Should work fine on interior and exterior nodes.
+ * We only cache a small number of extents stored directly on the
+ * inode, so linear order operations are acceptable. If we ever want
+ * to increase the size of the extent map, then these algorithms must
+ * get smarter.
*/
-static int ocfs2_search_extent_list(struct ocfs2_extent_list *el,
- u32 v_cluster)
+
+void ocfs2_extent_map_init(struct inode *inode)
+{
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+
+ oi->ip_extent_map.em_num_items = 0;
+ INIT_LIST_HEAD(&oi->ip_extent_map.em_list);
+}
+
+static void __ocfs2_extent_map_lookup(struct ocfs2_extent_map *em,
+ unsigned int cpos,
+ struct ocfs2_extent_map_item **ret_emi)
+{
+ unsigned int range;
+ struct ocfs2_extent_map_item *emi;
+
+ *ret_emi = NULL;
+
+ list_for_each_entry(emi, &em->em_list, ei_list) {
+ range = emi->ei_cpos + emi->ei_clusters;
+
+ if (cpos >= emi->ei_cpos && cpos < range) {
+ list_move(&emi->ei_list, &em->em_list);
+
+ *ret_emi = emi;
+ break;
+ }
+ }
+}
+
+static int ocfs2_extent_map_lookup(struct inode *inode, unsigned int cpos,
+ unsigned int *phys, unsigned int *len,
+ unsigned int *flags)
+{
+ unsigned int coff;
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+ struct ocfs2_extent_map_item *emi;
+
+ spin_lock(&oi->ip_lock);
+
+ __ocfs2_extent_map_lookup(&oi->ip_extent_map, cpos, &emi);
+ if (emi) {
+ coff = cpos - emi->ei_cpos;
+ *phys = emi->ei_phys + coff;
+ if (len)
+ *len = emi->ei_clusters - coff;
+ if (flags)
+ *flags = emi->ei_flags;
+ }
+
+ spin_unlock(&oi->ip_lock);
+
+ if (emi == NULL)
+ return -ENOENT;
+
+ return 0;
+}
+
+/*
+ * Forget about all clusters equal to or greater than cpos.
+ */
+void ocfs2_extent_map_trunc(struct inode *inode, unsigned int cpos)
+{
+ struct ocfs2_extent_map_item *emi, *n;
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+ struct ocfs2_extent_map *em = &oi->ip_extent_map;
+ LIST_HEAD(tmp_list);
+ unsigned int range;
+
+ spin_lock(&oi->ip_lock);
+ list_for_each_entry_safe(emi, n, &em->em_list, ei_list) {
+ if (emi->ei_cpos >= cpos) {
+ /* Full truncate of this record. */
+ list_move(&emi->ei_list, &tmp_list);
+ BUG_ON(em->em_num_items == 0);
+ em->em_num_items--;
+ continue;
+ }
+
+ range = emi->ei_cpos + emi->ei_clusters;
+ if (range > cpos) {
+ /* Partial truncate */
+ emi->ei_clusters = cpos - emi->ei_cpos;
+ }
+ }
+ spin_unlock(&oi->ip_lock);
+
+ list_for_each_entry_safe(emi, n, &tmp_list, ei_list) {
+ list_del(&emi->ei_list);
+ kfree(emi);
+ }
+}
+
+/*
+ * Is any part of emi2 contained within emi1
+ */
+static int ocfs2_ei_is_contained(struct ocfs2_extent_map_item *emi1,
+ struct ocfs2_extent_map_item *emi2)
+{
+ unsigned int range1, range2;
+
+ /*
+ * Check if logical start of emi2 is inside emi1
+ */
+ range1 = emi1->ei_cpos + emi1->ei_clusters;
+ if (emi2->ei_cpos >= emi1->ei_cpos && emi2->ei_cpos < range1)
+ return 1;
+
+ /*
+ * Check if logical end of emi2 is inside emi1
+ */
+ range2 = emi2->ei_cpos + emi2->ei_clusters;
+ if (range2 > emi1->ei_cpos && range2 <= range1)
+ return 1;
+
+ return 0;
+}
+
+static void ocfs2_copy_emi_fields(struct ocfs2_extent_map_item *dest,
+ struct ocfs2_extent_map_item *src)
+{
+ dest->ei_cpos = src->ei_cpos;
+ dest->ei_phys = src->ei_phys;
+ dest->ei_clusters = src->ei_clusters;
+ dest->ei_flags = src->ei_flags;
+}
+
+/*
+ * Try to merge emi with ins. Returns 1 if merge succeeds, zero
+ * otherwise.
+ */
+static int ocfs2_try_to_merge_extent_map(struct ocfs2_extent_map_item *emi,
+ struct ocfs2_extent_map_item *ins)
+{
+ /*
+ * Handle contiguousness
+ */
+ if (ins->ei_phys == (emi->ei_phys + emi->ei_clusters) &&
+ ins->ei_cpos == (emi->ei_cpos + emi->ei_clusters) &&
+ ins->ei_flags == emi->ei_flags) {
+ emi->ei_clusters += ins->ei_clusters;
+ return 1;
+ } else if ((ins->ei_phys + ins->ei_clusters) == emi->ei_phys &&
+ (ins->ei_cpos + ins->ei_clusters) == emi->ei_phys &&
+ ins->ei_flags == emi->ei_flags) {
+ emi->ei_phys = ins->ei_phys;
+ emi->ei_cpos = ins->ei_cpos;
+ emi->ei_clusters += ins->ei_clusters;
+ return 1;
+ }
+
+ /*
+ * Overlapping extents - this shouldn't happen unless we've
+ * split an extent to change it's flags. That is exceedingly
+ * rare, so there's no sense in trying to optimize it yet.
+ */
+ if (ocfs2_ei_is_contained(emi, ins) ||
+ ocfs2_ei_is_contained(ins, emi)) {
+ ocfs2_copy_emi_fields(emi, ins);
+ return 1;
+ }
+
+ /* No merge was possible. */
+ return 0;
+}
+
+/*
+ * In order to reduce complexity on the caller, this insert function
+ * is intentionally liberal in what it will accept.
+ *
+ * The only rule is that the truncate call *must* be used whenever
+ * records have been deleted. This avoids inserting overlapping
+ * records with different physical mappings.
+ */
+void ocfs2_extent_map_insert_rec(struct inode *inode,
+ struct ocfs2_extent_rec *rec)
+{
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+ struct ocfs2_extent_map *em = &oi->ip_extent_map;
+ struct ocfs2_extent_map_item *emi, *new_emi = NULL;
+ struct ocfs2_extent_map_item ins;
+
+ ins.ei_cpos = le32_to_cpu(rec->e_cpos);
+ ins.ei_phys = ocfs2_blocks_to_clusters(inode->i_sb,
+ le64_to_cpu(rec->e_blkno));
+ ins.ei_clusters = le16_to_cpu(rec->e_leaf_clusters);
+ ins.ei_flags = rec->e_flags;
+
+search:
+ spin_lock(&oi->ip_lock);
+
+ list_for_each_entry(emi, &em->em_list, ei_list) {
+ if (ocfs2_try_to_merge_extent_map(emi, &ins)) {
+ list_move(&emi->ei_list, &em->em_list);
+ spin_unlock(&oi->ip_lock);
+ goto out;
+ }
+ }
+
+ /*
+ * No item could be merged.
+ *
+ * Either allocate and add a new item, or overwrite the last recently
+ * inserted.
+ */
+
+ if (em->em_num_items < OCFS2_MAX_EXTENT_MAP_ITEMS) {
+ if (new_emi == NULL) {
+ spin_unlock(&oi->ip_lock);
+
+ new_emi = kmalloc(sizeof(*new_emi), GFP_NOFS);
+ if (new_emi == NULL)
+ goto out;
+
+ goto search;
+ }
+
+ ocfs2_copy_emi_fields(new_emi, &ins);
+ list_add(&new_emi->ei_list, &em->em_list);
+ em->em_num_items++;
+ new_emi = NULL;
+ } else {
+ BUG_ON(list_empty(&em->em_list) || em->em_num_items == 0);
+ emi = list_entry(em->em_list.prev,
+ struct ocfs2_extent_map_item, ei_list);
+ list_move(&emi->ei_list, &em->em_list);
+ ocfs2_copy_emi_fields(emi, &ins);
+ }
+
+ spin_unlock(&oi->ip_lock);
+
+out:
+ if (new_emi)
+ kfree(new_emi);
+}
+
+/*
+ * Return the 1st index within el which contains an extent start
+ * larger than v_cluster.
+ */
+static int ocfs2_search_for_hole_index(struct ocfs2_extent_list *el,
+ u32 v_cluster)
{
- int ret = -1;
int i;
struct ocfs2_extent_rec *rec;
- u32 rec_end, rec_start;
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);
- rec_end = rec_start + le32_to_cpu(rec->e_clusters);
-
- if (v_cluster >= rec_start && v_cluster < rec_end) {
- ret = i;
+ if (v_cluster < le32_to_cpu(rec->e_cpos))
break;
+ }
+
+ return i;
+}
+
+/*
+ * Figure out the size of a hole which starts at v_cluster within the given
+ * extent list.
+ *
+ * If there is no more allocation past v_cluster, we return the maximum
+ * cluster size minus v_cluster.
+ *
+ * If we have in-inode extents, then el points to the dinode list and
+ * eb_bh is NULL. Otherwise, eb_bh should point to the extent block
+ * containing el.
+ */
+static int ocfs2_figure_hole_clusters(struct inode *inode,
+ struct ocfs2_extent_list *el,
+ struct buffer_head *eb_bh,
+ u32 v_cluster,
+ u32 *num_clusters)
+{
+ int ret, i;
+ struct buffer_head *next_eb_bh = NULL;
+ struct ocfs2_extent_block *eb, *next_eb;
+
+ i = ocfs2_search_for_hole_index(el, v_cluster);
+
+ if (i == le16_to_cpu(el->l_next_free_rec) && eb_bh) {
+ eb = (struct ocfs2_extent_block *)eb_bh->b_data;
+
+ /*
+ * Check the next leaf for any extents.
+ */
+
+ if (le64_to_cpu(eb->h_next_leaf_blk) == 0ULL)
+ goto no_more_extents;
+
+ ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
+ le64_to_cpu(eb->h_next_leaf_blk),
+ &next_eb_bh, OCFS2_BH_CACHED, inode);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
}
+ next_eb = (struct ocfs2_extent_block *)next_eb_bh->b_data;
+
+ if (!OCFS2_IS_VALID_EXTENT_BLOCK(next_eb)) {
+ ret = -EROFS;
+ OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, next_eb);
+ goto out;
+ }
+
+ el = &next_eb->h_list;
+
+ i = ocfs2_search_for_hole_index(el, v_cluster);
+ }
+
+no_more_extents:
+ if (i == le16_to_cpu(el->l_next_free_rec)) {
+ /*
+ * We're at the end of our existing allocation. Just
+ * return the maximum number of clusters we could
+ * possibly allocate.
+ */
+ *num_clusters = UINT_MAX - v_cluster;
+ } else {
+ *num_clusters = le32_to_cpu(el->l_recs[i].e_cpos) - v_cluster;
}
+ ret = 0;
+out:
+ brelse(next_eb_bh);
return ret;
}
-static int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
- u32 *p_cluster, u32 *num_clusters)
+int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
+ u32 *p_cluster, u32 *num_clusters,
+ unsigned int *extent_flags)
{
int ret, i;
+ unsigned int flags = 0;
struct buffer_head *di_bh = NULL;
struct buffer_head *eb_bh = NULL;
struct ocfs2_dinode *di;
struct ocfs2_extent_rec *rec;
u32 coff;
+ if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
+ ret = -ERANGE;
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ret = ocfs2_extent_map_lookup(inode, v_cluster, p_cluster,
+ num_clusters, extent_flags);
+ if (ret == 0)
+ goto out;
+
ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), OCFS2_I(inode)->ip_blkno,
&di_bh, OCFS2_BH_CACHED, inode);
if (ret) {
eb = (struct ocfs2_extent_block *) eb_bh->b_data;
el = &eb->h_list;
+
+ if (el->l_tree_depth) {
+ ocfs2_error(inode->i_sb,
+ "Inode %lu has non zero tree depth in "
+ "leaf block %llu\n", inode->i_ino,
+ (unsigned long long)eb_bh->b_blocknr);
+ ret = -EROFS;
+ goto out;
+ }
}
i = ocfs2_search_extent_list(el, v_cluster);
if (i == -1) {
/*
* A hole was found. Return some canned values that
- * callers can key on.
+ * callers can key on. If asked for, num_clusters will
+ * be populated with the size of the hole.
*/
*p_cluster = 0;
- if (num_clusters)
- *num_clusters = 1;
+ if (num_clusters) {
+ ret = ocfs2_figure_hole_clusters(inode, el, eb_bh,
+ v_cluster,
+ num_clusters);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+ }
} else {
rec = &el->l_recs[i];
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));
+ ocfs2_rec_clusters(el, rec));
ret = -EROFS;
goto out;
}
*p_cluster = *p_cluster + coff;
if (num_clusters)
- *num_clusters = le32_to_cpu(rec->e_clusters) - coff;
+ *num_clusters = ocfs2_rec_clusters(el, rec) - coff;
+
+ flags = rec->e_flags;
+
+ ocfs2_extent_map_insert_rec(inode, rec);
}
+ if (extent_flags)
+ *extent_flags = flags;
+
out:
brelse(di_bh);
brelse(eb_bh);
* all while the map is in the process of being updated.
*/
int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
- int *ret_count)
+ u64 *ret_count, unsigned int *extent_flags)
{
int ret;
int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
cpos = ocfs2_blocks_to_clusters(inode->i_sb, v_blkno);
- ret = ocfs2_get_clusters(inode, cpos, &p_cluster, &num_clusters);
+ ret = ocfs2_get_clusters(inode, cpos, &p_cluster, &num_clusters,
+ extent_flags);
if (ret) {
mlog_errno(ret);
goto out;
projects / linux-2.6-omap-h63xx.git / blobdiff