ocfs2: Require an inode for ocfs2_read_block(s)().
[pandora-kernel.git] / fs / ocfs2 / extent_map.c
index c58668a..5b48221 100644 (file)
@@ -25,6 +25,7 @@
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/types.h>
+#include <linux/fiemap.h>
 
 #define MLOG_MASK_PREFIX ML_EXTENT_MAP
 #include <cluster/masklog.h>
@@ -32,6 +33,7 @@
 #include "ocfs2.h"
 
 #include "alloc.h"
+#include "dlmglue.h"
 #include "extent_map.h"
 #include "inode.h"
 #include "super.h"
@@ -282,6 +284,51 @@ out:
                kfree(new_emi);
 }
 
+static int ocfs2_last_eb_is_empty(struct inode *inode,
+                                 struct ocfs2_dinode *di)
+{
+       int ret, next_free;
+       u64 last_eb_blk = le64_to_cpu(di->i_last_eb_blk);
+       struct buffer_head *eb_bh = NULL;
+       struct ocfs2_extent_block *eb;
+       struct ocfs2_extent_list *el;
+
+       ret = ocfs2_read_block(inode, last_eb_blk,
+                              &eb_bh, OCFS2_BH_CACHED);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       eb = (struct ocfs2_extent_block *) eb_bh->b_data;
+       el = &eb->h_list;
+
+       if (!OCFS2_IS_VALID_EXTENT_BLOCK(eb)) {
+               ret = -EROFS;
+               OCFS2_RO_ON_INVALID_EXTENT_BLOCK(inode->i_sb, eb);
+               goto out;
+       }
+
+       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;
+       }
+
+       next_free = le16_to_cpu(el->l_next_free_rec);
+
+       if (next_free == 0 ||
+           (next_free == 1 && ocfs2_is_empty_extent(&el->l_recs[0])))
+               ret = 1;
+
+out:
+       brelse(eb_bh);
+       return ret;
+}
+
 /*
  * Return the 1st index within el which contains an extent start
  * larger than v_cluster.
@@ -335,9 +382,9 @@ static int ocfs2_figure_hole_clusters(struct inode *inode,
                if (le64_to_cpu(eb->h_next_leaf_blk) == 0ULL)
                        goto no_more_extents;
 
-               ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
+               ret = ocfs2_read_block(inode,
                                       le64_to_cpu(eb->h_next_leaf_blk),
-                                      &next_eb_bh, OCFS2_BH_CACHED, inode);
+                                      &next_eb_bh, OCFS2_BH_CACHED);
                if (ret) {
                        mlog_errno(ret);
                        goto out;
@@ -373,42 +420,28 @@ out:
        return ret;
 }
 
-int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
-                      u32 *p_cluster, u32 *num_clusters,
-                      unsigned int *extent_flags)
+static int ocfs2_get_clusters_nocache(struct inode *inode,
+                                     struct buffer_head *di_bh,
+                                     u32 v_cluster, unsigned int *hole_len,
+                                     struct ocfs2_extent_rec *ret_rec,
+                                     unsigned int *is_last)
 {
-       int ret, i;
-       unsigned int flags = 0;
-       struct buffer_head *di_bh = NULL;
-       struct buffer_head *eb_bh = NULL;
+       int i, ret, tree_height, len;
        struct ocfs2_dinode *di;
-       struct ocfs2_extent_block *eb;
+       struct ocfs2_extent_block *uninitialized_var(eb);
        struct ocfs2_extent_list *el;
        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;
+       struct buffer_head *eb_bh = NULL;
 
-       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);
-               goto out;
-       }
+       memset(ret_rec, 0, sizeof(*ret_rec));
+       if (is_last)
+               *is_last = 0;
 
        di = (struct ocfs2_dinode *) di_bh->b_data;
        el = &di->id2.i_list;
+       tree_height = le16_to_cpu(el->l_tree_depth);
 
-       if (el->l_tree_depth) {
+       if (tree_height > 0) {
                ret = ocfs2_find_leaf(inode, el, v_cluster, &eb_bh);
                if (ret) {
                        mlog_errno(ret);
@@ -431,46 +464,203 @@ int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
        i = ocfs2_search_extent_list(el, v_cluster);
        if (i == -1) {
                /*
-                * A hole was found. Return some canned values that
-                * callers can key on. If asked for, num_clusters will
-                * be populated with the size of the hole.
+                * Holes can be larger than the maximum size of an
+                * extent, so we return their lengths in a seperate
+                * field.
                 */
-               *p_cluster = 0;
-               if (num_clusters) {
+               if (hole_len) {
                        ret = ocfs2_figure_hole_clusters(inode, el, eb_bh,
-                                                        v_cluster,
-                                                        num_clusters);
+                                                        v_cluster, &len);
                        if (ret) {
                                mlog_errno(ret);
                                goto out;
                        }
+
+                       *hole_len = len;
+               }
+               goto out_hole;
+       }
+
+       rec = &el->l_recs[i];
+
+       BUG_ON(v_cluster < 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),
+                           ocfs2_rec_clusters(el, rec));
+               ret = -EROFS;
+               goto out;
+       }
+
+       *ret_rec = *rec;
+
+       /*
+        * Checking for last extent is potentially expensive - we
+        * might have to look at the next leaf over to see if it's
+        * empty.
+        *
+        * The first two checks are to see whether the caller even
+        * cares for this information, and if the extent is at least
+        * the last in it's list.
+        *
+        * If those hold true, then the extent is last if any of the
+        * additional conditions hold true:
+        *  - Extent list is in-inode
+        *  - Extent list is right-most
+        *  - Extent list is 2nd to rightmost, with empty right-most
+        */
+       if (is_last) {
+               if (i == (le16_to_cpu(el->l_next_free_rec) - 1)) {
+                       if (tree_height == 0)
+                               *is_last = 1;
+                       else if (eb->h_blkno == di->i_last_eb_blk)
+                               *is_last = 1;
+                       else if (eb->h_next_leaf_blk == di->i_last_eb_blk) {
+                               ret = ocfs2_last_eb_is_empty(inode, di);
+                               if (ret < 0) {
+                                       mlog_errno(ret);
+                                       goto out;
+                               }
+                               if (ret == 1)
+                                       *is_last = 1;
+                       }
+               }
+       }
+
+out_hole:
+       ret = 0;
+out:
+       brelse(eb_bh);
+       return ret;
+}
+
+static void ocfs2_relative_extent_offsets(struct super_block *sb,
+                                         u32 v_cluster,
+                                         struct ocfs2_extent_rec *rec,
+                                         u32 *p_cluster, u32 *num_clusters)
+
+{
+       u32 coff = v_cluster - le32_to_cpu(rec->e_cpos);
+
+       *p_cluster = ocfs2_blocks_to_clusters(sb, le64_to_cpu(rec->e_blkno));
+       *p_cluster = *p_cluster + coff;
+
+       if (num_clusters)
+               *num_clusters = le16_to_cpu(rec->e_leaf_clusters) - coff;
+}
+
+int ocfs2_xattr_get_clusters(struct inode *inode, u32 v_cluster,
+                            u32 *p_cluster, u32 *num_clusters,
+                            struct ocfs2_extent_list *el)
+{
+       int ret = 0, i;
+       struct buffer_head *eb_bh = NULL;
+       struct ocfs2_extent_block *eb;
+       struct ocfs2_extent_rec *rec;
+       u32 coff;
+
+       if (el->l_tree_depth) {
+               ret = ocfs2_find_leaf(inode, el, v_cluster, &eb_bh);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
                }
+
+               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 "
+                                   "xattr 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) {
+               ret = -EROFS;
+               mlog_errno(ret);
+               goto out;
        } else {
                rec = &el->l_recs[i];
-
                BUG_ON(v_cluster < 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,
+                                   "record (%u, %u, 0) in xattr", inode->i_ino,
                                    le32_to_cpu(rec->e_cpos),
                                    ocfs2_rec_clusters(el, rec));
                        ret = -EROFS;
                        goto out;
                }
-
                coff = v_cluster - le32_to_cpu(rec->e_cpos);
-
                *p_cluster = ocfs2_blocks_to_clusters(inode->i_sb,
                                                    le64_to_cpu(rec->e_blkno));
                *p_cluster = *p_cluster + coff;
-
                if (num_clusters)
                        *num_clusters = ocfs2_rec_clusters(el, rec) - coff;
+       }
+out:
+       if (eb_bh)
+               brelse(eb_bh);
+       return ret;
+}
+
+int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
+                      u32 *p_cluster, u32 *num_clusters,
+                      unsigned int *extent_flags)
+{
+       int ret;
+       unsigned int uninitialized_var(hole_len), flags = 0;
+       struct buffer_head *di_bh = NULL;
+       struct ocfs2_extent_rec rec;
+
+       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(inode, OCFS2_I(inode)->ip_blkno,
+                              &di_bh, OCFS2_BH_CACHED);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
 
-               flags = rec->e_flags;
+       ret = ocfs2_get_clusters_nocache(inode, di_bh, v_cluster, &hole_len,
+                                        &rec, NULL);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       if (rec.e_blkno == 0ULL) {
+               /*
+                * A hole was found. Return some canned values that
+                * 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 = hole_len;
+               }
+       } else {
+               ocfs2_relative_extent_offsets(inode->i_sb, v_cluster, &rec,
+                                             p_cluster, num_clusters);
+               flags = rec.e_flags;
 
-               ocfs2_extent_map_insert_rec(inode, rec);
+               ocfs2_extent_map_insert_rec(inode, &rec);
        }
 
        if (extent_flags)
@@ -478,7 +668,6 @@ int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
 
 out:
        brelse(di_bh);
-       brelse(eb_bh);
        return ret;
 }
 
@@ -521,3 +710,114 @@ int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
 out:
        return ret;
 }
+
+static int ocfs2_fiemap_inline(struct inode *inode, struct buffer_head *di_bh,
+                              struct fiemap_extent_info *fieinfo,
+                              u64 map_start)
+{
+       int ret;
+       unsigned int id_count;
+       struct ocfs2_dinode *di;
+       u64 phys;
+       u32 flags = FIEMAP_EXTENT_DATA_INLINE|FIEMAP_EXTENT_LAST;
+       struct ocfs2_inode_info *oi = OCFS2_I(inode);
+
+       di = (struct ocfs2_dinode *)di_bh->b_data;
+       id_count = le16_to_cpu(di->id2.i_data.id_count);
+
+       if (map_start < id_count) {
+               phys = oi->ip_blkno << inode->i_sb->s_blocksize_bits;
+               phys += offsetof(struct ocfs2_dinode, id2.i_data.id_data);
+
+               ret = fiemap_fill_next_extent(fieinfo, 0, phys, id_count,
+                                             flags);
+               if (ret < 0)
+                       return ret;
+       }
+
+       return 0;
+}
+
+#define OCFS2_FIEMAP_FLAGS     (FIEMAP_FLAG_SYNC)
+
+int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+                u64 map_start, u64 map_len)
+{
+       int ret, is_last;
+       u32 mapping_end, cpos;
+       unsigned int hole_size;
+       struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+       u64 len_bytes, phys_bytes, virt_bytes;
+       struct buffer_head *di_bh = NULL;
+       struct ocfs2_extent_rec rec;
+
+       ret = fiemap_check_flags(fieinfo, OCFS2_FIEMAP_FLAGS);
+       if (ret)
+               return ret;
+
+       ret = ocfs2_inode_lock(inode, &di_bh, 0);
+       if (ret) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       down_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+       /*
+        * Handle inline-data separately.
+        */
+       if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
+               ret = ocfs2_fiemap_inline(inode, di_bh, fieinfo, map_start);
+               goto out_unlock;
+       }
+
+       cpos = map_start >> osb->s_clustersize_bits;
+       mapping_end = ocfs2_clusters_for_bytes(inode->i_sb,
+                                              map_start + map_len);
+       mapping_end -= cpos;
+       is_last = 0;
+       while (cpos < mapping_end && !is_last) {
+               u32 fe_flags;
+
+               ret = ocfs2_get_clusters_nocache(inode, di_bh, cpos,
+                                                &hole_size, &rec, &is_last);
+               if (ret) {
+                       mlog_errno(ret);
+                       goto out;
+               }
+
+               if (rec.e_blkno == 0ULL) {
+                       cpos += hole_size;
+                       continue;
+               }
+
+               fe_flags = 0;
+               if (rec.e_flags & OCFS2_EXT_UNWRITTEN)
+                       fe_flags |= FIEMAP_EXTENT_UNWRITTEN;
+               if (is_last)
+                       fe_flags |= FIEMAP_EXTENT_LAST;
+               len_bytes = (u64)le16_to_cpu(rec.e_leaf_clusters) << osb->s_clustersize_bits;
+               phys_bytes = le64_to_cpu(rec.e_blkno) << osb->sb->s_blocksize_bits;
+               virt_bytes = (u64)le32_to_cpu(rec.e_cpos) << osb->s_clustersize_bits;
+
+               ret = fiemap_fill_next_extent(fieinfo, virt_bytes, phys_bytes,
+                                             len_bytes, fe_flags);
+               if (ret)
+                       break;
+
+               cpos = le32_to_cpu(rec.e_cpos)+ le16_to_cpu(rec.e_leaf_clusters);
+       }
+
+       if (ret > 0)
+               ret = 0;
+
+out_unlock:
+       brelse(di_bh);
+
+       up_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+       ocfs2_inode_unlock(inode, 0);
+out:
+
+       return ret;
+}