ocfs2: Pass suballocation results back via a structure.
authorJoel Becker <joel.becker@oracle.com>
Tue, 13 Apr 2010 06:30:19 +0000 (14:30 +0800)
committerTao Ma <tao.ma@oracle.com>
Tue, 13 Apr 2010 06:30:19 +0000 (14:30 +0800)
We're going to be adding more info to a suballocator allocation.  Rather
than growing every function in the chain, let's pass a result structure
around.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
fs/ocfs2/suballoc.c
fs/ocfs2/suballoc.h

index 2f75395..3d823cf 100644 (file)
 
 #define OCFS2_MAX_TO_STEAL             1024
 
+struct ocfs2_suballoc_result {
+       u64             sr_bg_blkno;    /* The bg we allocated from */
+       unsigned int    sr_bit_offset;  /* The bit in the bg */
+       unsigned int    sr_bits;        /* How many bits we claimed */
+};
+
 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
@@ -74,20 +80,18 @@ static int ocfs2_cluster_group_search(struct inode *inode,
                                      struct buffer_head *group_bh,
                                      u32 bits_wanted, u32 min_bits,
                                      u64 max_block,
-                                     u16 *bit_off, u16 *bits_found);
+                                     struct ocfs2_suballoc_result *res);
 static int ocfs2_block_group_search(struct inode *inode,
                                    struct buffer_head *group_bh,
                                    u32 bits_wanted, u32 min_bits,
                                    u64 max_block,
-                                   u16 *bit_off, u16 *bits_found);
+                                   struct ocfs2_suballoc_result *res);
 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
                                     struct ocfs2_alloc_context *ac,
                                     handle_t *handle,
                                     u32 bits_wanted,
                                     u32 min_bits,
-                                    u16 *bit_off,
-                                    unsigned int *num_bits,
-                                    u64 *bg_blkno);
+                                    struct ocfs2_suballoc_result *res);
 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
                                         int nr);
 static inline int ocfs2_block_group_set_bits(handle_t *handle,
@@ -1248,8 +1252,7 @@ static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
                                             struct buffer_head *bg_bh,
                                             unsigned int bits_wanted,
                                             unsigned int total_bits,
-                                            u16 *bit_off,
-                                            u16 *bits_found)
+                                            struct ocfs2_suballoc_result *res)
 {
        void *bitmap;
        u16 best_offset, best_size;
@@ -1293,14 +1296,9 @@ static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
                }
        }
 
-       /* XXX: I think the first clause is equivalent to the second
-        *      - jlbec */
-       if (found == bits_wanted) {
-               *bit_off = start - found;
-               *bits_found = found;
-       } else if (best_size) {
-               *bit_off = best_offset;
-               *bits_found = best_size;
+       if (best_size) {
+               res->sr_bit_offset = best_offset;
+               res->sr_bits = best_size;
        } else {
                status = -ENOSPC;
                /* No error log here -- see the comment above
@@ -1456,14 +1454,13 @@ static int ocfs2_cluster_group_search(struct inode *inode,
                                      struct buffer_head *group_bh,
                                      u32 bits_wanted, u32 min_bits,
                                      u64 max_block,
-                                     u16 *bit_off, u16 *bits_found)
+                                     struct ocfs2_suballoc_result *res)
 {
        int search = -ENOSPC;
        int ret;
        u64 blkoff;
        struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
-       u16 tmp_off, tmp_found;
        unsigned int max_bits, gd_cluster_off;
 
        BUG_ON(!ocfs2_is_cluster_bitmap(inode));
@@ -1490,15 +1487,15 @@ static int ocfs2_cluster_group_search(struct inode *inode,
 
                ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
                                                        group_bh, bits_wanted,
-                                                       max_bits,
-                                                       &tmp_off, &tmp_found);
+                                                       max_bits, res);
                if (ret)
                        return ret;
 
                if (max_block) {
                        blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
                                                          gd_cluster_off +
-                                                         tmp_off + tmp_found);
+                                                         res->sr_bit_offset +
+                                                         res->sr_bits);
                        mlog(0, "Checking %llu against %llu\n",
                             (unsigned long long)blkoff,
                             (unsigned long long)max_block);
@@ -1510,16 +1507,14 @@ static int ocfs2_cluster_group_search(struct inode *inode,
                 * return success, but we still want to return
                 * -ENOSPC unless it found the minimum number
                 * of bits. */
-               if (min_bits <= tmp_found) {
-                       *bit_off = tmp_off;
-                       *bits_found = tmp_found;
+               if (min_bits <= res->sr_bits)
                        search = 0; /* success */
-               } else if (tmp_found) {
+               else if (res->sr_bits) {
                        /*
                         * Don't show bits which we'll be returning
                         * for allocation to the local alloc bitmap.
                         */
-                       ocfs2_local_alloc_seen_free_bits(osb, tmp_found);
+                       ocfs2_local_alloc_seen_free_bits(osb, res->sr_bits);
                }
        }
 
@@ -1530,7 +1525,7 @@ static int ocfs2_block_group_search(struct inode *inode,
                                    struct buffer_head *group_bh,
                                    u32 bits_wanted, u32 min_bits,
                                    u64 max_block,
-                                   u16 *bit_off, u16 *bits_found)
+                                   struct ocfs2_suballoc_result *res)
 {
        int ret = -ENOSPC;
        u64 blkoff;
@@ -1543,10 +1538,10 @@ static int ocfs2_block_group_search(struct inode *inode,
                ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
                                                        group_bh, bits_wanted,
                                                        le16_to_cpu(bg->bg_bits),
-                                                       bit_off, bits_found);
+                                                       res);
                if (!ret && max_block) {
-                       blkoff = le64_to_cpu(bg->bg_blkno) + *bit_off +
-                               *bits_found;
+                       blkoff = le64_to_cpu(bg->bg_blkno) +
+                               res->sr_bit_offset + res->sr_bits;
                        mlog(0, "Checking %llu against %llu\n",
                             (unsigned long long)blkoff,
                             (unsigned long long)max_block);
@@ -1589,20 +1584,17 @@ static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
                                  handle_t *handle,
                                  u32 bits_wanted,
                                  u32 min_bits,
-                                 u16 *bit_off,
-                                 unsigned int *num_bits,
-                                 u64 gd_blkno,
+                                 struct ocfs2_suballoc_result *res,
                                  u16 *bits_left)
 {
        int ret;
-       u16 found;
        struct buffer_head *group_bh = NULL;
        struct ocfs2_group_desc *gd;
        struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
        struct inode *alloc_inode = ac->ac_inode;
 
-       ret = ocfs2_read_group_descriptor(alloc_inode, di, gd_blkno,
-                                         &group_bh);
+       ret = ocfs2_read_group_descriptor(alloc_inode, di,
+                                         res->sr_bg_blkno, &group_bh);
        if (ret < 0) {
                mlog_errno(ret);
                return ret;
@@ -1610,17 +1602,15 @@ static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
 
        gd = (struct ocfs2_group_desc *) group_bh->b_data;
        ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
-                                 ac->ac_max_block, bit_off, &found);
+                                 ac->ac_max_block, res);
        if (ret < 0) {
                if (ret != -ENOSPC)
                        mlog_errno(ret);
                goto out;
        }
 
-       *num_bits = found;
-
        ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
-                                              *num_bits,
+                                              res->sr_bits,
                                               le16_to_cpu(gd->bg_chain));
        if (ret < 0) {
                mlog_errno(ret);
@@ -1628,7 +1618,7 @@ static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
        }
 
        ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
-                                        *bit_off, *num_bits);
+                                        res->sr_bit_offset, res->sr_bits);
        if (ret < 0)
                mlog_errno(ret);
 
@@ -1644,13 +1634,11 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
                              handle_t *handle,
                              u32 bits_wanted,
                              u32 min_bits,
-                             u16 *bit_off,
-                             unsigned int *num_bits,
-                             u64 *bg_blkno,
+                             struct ocfs2_suballoc_result *res,
                              u16 *bits_left)
 {
        int status;
-       u16 chain, tmp_bits;
+       u16 chain;
        u32 tmp_used;
        u64 next_group;
        struct inode *alloc_inode = ac->ac_inode;
@@ -1679,8 +1667,8 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
         * the 1st group with any empty bits. */
        while ((status = ac->ac_group_search(alloc_inode, group_bh,
                                             bits_wanted, min_bits,
-                                            ac->ac_max_block, bit_off,
-                                            &tmp_bits)) == -ENOSPC) {
+                                            ac->ac_max_block,
+                                            res)) == -ENOSPC) {
                if (!bg->bg_next_group)
                        break;
 
@@ -1705,11 +1693,11 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
        }
 
        mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
-            tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
+            res->sr_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
 
-       *num_bits = tmp_bits;
+       res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
 
-       BUG_ON(*num_bits == 0);
+       BUG_ON(res->sr_bits == 0);
 
        /*
         * Keep track of previous block descriptor read. When
@@ -1726,7 +1714,7 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
         */
        if (ac->ac_allow_chain_relink &&
            (prev_group_bh) &&
-           (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
+           (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
                status = ocfs2_relink_block_group(handle, alloc_inode,
                                                  ac->ac_bh, group_bh,
                                                  prev_group_bh, chain);
@@ -1748,25 +1736,24 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
        }
 
        tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
-       fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
-       le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
+       fe->id1.bitmap1.i_used = cpu_to_le32(res->sr_bits + tmp_used);
+       le32_add_cpu(&cl->cl_recs[chain].c_free, -res->sr_bits);
        ocfs2_journal_dirty(handle, ac->ac_bh);
 
        status = ocfs2_block_group_set_bits(handle,
                                            alloc_inode,
                                            bg,
                                            group_bh,
-                                           *bit_off,
-                                           *num_bits);
+                                           res->sr_bit_offset,
+                                           res->sr_bits);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }
 
-       mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
+       mlog(0, "Allocated %u bits from suballocator %llu\n", res->sr_bits,
             (unsigned long long)le64_to_cpu(fe->i_blkno));
 
-       *bg_blkno = le64_to_cpu(bg->bg_blkno);
        *bits_left = le16_to_cpu(bg->bg_free_bits_count);
 bail:
        brelse(group_bh);
@@ -1782,14 +1769,11 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
                                     handle_t *handle,
                                     u32 bits_wanted,
                                     u32 min_bits,
-                                    u16 *bit_off,
-                                    unsigned int *num_bits,
-                                    u64 *bg_blkno)
+                                    struct ocfs2_suballoc_result *res)
 {
        int status;
        u16 victim, i;
        u16 bits_left = 0;
-       u64 hint_blkno = ac->ac_last_group;
        struct ocfs2_chain_list *cl;
        struct ocfs2_dinode *fe;
 
@@ -1816,22 +1800,16 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
                goto bail;
        }
 
-       if (hint_blkno) {
+       res->sr_bg_blkno = ac->ac_last_group;
+       if (res->sr_bg_blkno) {
                /* Attempt to short-circuit the usual search mechanism
                 * by jumping straight to the most recently used
                 * allocation group. This helps us mantain some
                 * contiguousness across allocations. */
                status = ocfs2_search_one_group(ac, handle, bits_wanted,
-                                               min_bits, bit_off, num_bits,
-                                               hint_blkno, &bits_left);
-               if (!status) {
-                       /* Be careful to update *bg_blkno here as the
-                        * caller is expecting it to be filled in, and
-                        * ocfs2_search_one_group() won't do that for
-                        * us. */
-                       *bg_blkno = hint_blkno;
+                                               min_bits, res, &bits_left);
+               if (!status)
                        goto set_hint;
-               }
                if (status < 0 && status != -ENOSPC) {
                        mlog_errno(status);
                        goto bail;
@@ -1844,8 +1822,8 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
        ac->ac_chain = victim;
        ac->ac_allow_chain_relink = 1;
 
-       status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
-                                   num_bits, bg_blkno, &bits_left);
+       status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
+                                   res, &bits_left);
        if (!status)
                goto set_hint;
        if (status < 0 && status != -ENOSPC) {
@@ -1869,8 +1847,7 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
 
                ac->ac_chain = i;
                status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
-                                           bit_off, num_bits, bg_blkno,
-                                           &bits_left);
+                                           res, &bits_left);
                if (!status)
                        break;
                if (status < 0 && status != -ENOSPC) {
@@ -1887,7 +1864,7 @@ set_hint:
                if (bits_left < min_bits)
                        ac->ac_last_group = 0;
                else
-                       ac->ac_last_group = *bg_blkno;
+                       ac->ac_last_group = res->sr_bg_blkno;
        }
 
 bail:
@@ -1904,7 +1881,7 @@ int ocfs2_claim_metadata(struct ocfs2_super *osb,
                         u64 *blkno_start)
 {
        int status;
-       u64 bg_blkno;
+       struct ocfs2_suballoc_result res;
 
        BUG_ON(!ac);
        BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
@@ -1915,17 +1892,17 @@ int ocfs2_claim_metadata(struct ocfs2_super *osb,
                                           handle,
                                           bits_wanted,
                                           1,
-                                          suballoc_bit_start,
-                                          num_bits,
-                                          &bg_blkno);
+                                          &res);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }
        atomic_inc(&osb->alloc_stats.bg_allocs);
 
-       *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
-       ac->ac_bits_given += (*num_bits);
+       *suballoc_bit_start = res.sr_bit_offset;
+       *blkno_start = res.sr_bg_blkno + (u64)(res.sr_bit_offset);
+       ac->ac_bits_given += res.sr_bits;
+       *num_bits = res.sr_bits;
        status = 0;
 bail:
        mlog_exit(status);
@@ -1972,8 +1949,7 @@ int ocfs2_claim_new_inode(struct ocfs2_super *osb,
                          u64 *fe_blkno)
 {
        int status;
-       unsigned int num_bits;
-       u64 bg_blkno;
+       struct ocfs2_suballoc_result res;
 
        mlog_entry_void();
 
@@ -1989,18 +1965,17 @@ int ocfs2_claim_new_inode(struct ocfs2_super *osb,
                                           handle,
                                           1,
                                           1,
-                                          suballoc_bit,
-                                          &num_bits,
-                                          &bg_blkno);
+                                          &res);
        if (status < 0) {
                mlog_errno(status);
                goto bail;
        }
        atomic_inc(&osb->alloc_stats.bg_allocs);
 
-       BUG_ON(num_bits != 1);
+       BUG_ON(res.sr_bits != 1);
 
-       *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
+       *suballoc_bit = res.sr_bit_offset;
+       *fe_blkno = res.sr_bg_blkno + (u64)(res.sr_bit_offset);
        ac->ac_bits_given++;
        ocfs2_save_inode_ac_group(dir, ac);
        status = 0;
@@ -2080,8 +2055,7 @@ int __ocfs2_claim_clusters(struct ocfs2_super *osb,
 {
        int status;
        unsigned int bits_wanted = max_clusters;
-       u64 bg_blkno = 0;
-       u16 bg_bit_off;
+       struct ocfs2_suballoc_result res;
 
        mlog_entry_void();
 
@@ -2120,14 +2094,12 @@ int __ocfs2_claim_clusters(struct ocfs2_super *osb,
                                                   handle,
                                                   bits_wanted,
                                                   min_clusters,
-                                                  &bg_bit_off,
-                                                  num_clusters,
-                                                  &bg_blkno);
+                                                  &res);
                if (!status) {
                        *cluster_start =
                                ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
-                                                                bg_blkno,
-                                                                bg_bit_off);
+                                                                res.sr_bg_blkno,
+                                                                res.sr_bit_offset);
                        atomic_inc(&osb->alloc_stats.bitmap_data);
                }
        }
@@ -2137,7 +2109,8 @@ int __ocfs2_claim_clusters(struct ocfs2_super *osb,
                goto bail;
        }
 
-       ac->ac_bits_given += *num_clusters;
+       ac->ac_bits_given += res.sr_bits;
+       *num_clusters = res.sr_bits;
 
 bail:
        mlog_exit(status);
index da2f29a..f5a22cd 100644 (file)
 #ifndef _CHAINALLOC_H_
 #define _CHAINALLOC_H_
 
+struct ocfs2_suballoc_result;
 typedef int (group_search_t)(struct inode *,
                             struct buffer_head *,
                             u32,                       /* bits_wanted */
                             u32,                       /* min_bits */
                             u64,                       /* max_block */
-                            u16 *,                     /* *bit_off */
-                            u16 *);                    /* *bits_found */
+                            struct ocfs2_suballoc_result *);
+                                                       /* found bits */
 
 struct ocfs2_alloc_context {
        struct inode *ac_inode;    /* which bitmap are we allocating from? */