[PATCH] reiserfs: clean up bitmap block buffer head references

Similar to the SB_JOURNAL cleanup that was accepted a while ago, this patch
uses a temporary variable for buffer head references from the bitmap info
array.

This makes the code much more readable in some areas.

It also uses proper reference counting, doing a get_bh() after using the
pointer from the array and brelse()'ing it later.  This may seem silly, but a
later patch will replace the simple temporary variables with an actual read,
so the reference freeing will be used then.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index 1022347..44d9410 100644 (file)
--- a/fs/reiserfs/bitmap.c
+++ b/fs/reiserfs/bitmap.c
@@ -59,6 +59,7 @@ static inline void get_bit_address(struct super_block *s,
 int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value)
 {
        int bmap, offset;
+       struct buffer_head *bh;
 
        if (block == 0 || block >= SB_BLOCK_COUNT(s)) {
                reiserfs_warning(s,
@@ -96,20 +97,21 @@ int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value)
                return 0;
        }
 
-       if ((bit_value == 0 &&
-            reiserfs_test_le_bit(offset, SB_AP_BITMAP(s)[bmap].bh->b_data)) ||
-           (bit_value == 1 &&
-            reiserfs_test_le_bit(offset, SB_AP_BITMAP(s)[bmap].bh->b_data) == 0)) {
+       bh = SB_AP_BITMAP(s)[bmap].bh;
+       get_bh(bh);
+
+       if ((bit_value == 0 && reiserfs_test_le_bit(offset, bh->b_data)) ||
+           (bit_value == 1 && reiserfs_test_le_bit(offset, bh->b_data) == 0)) {
                reiserfs_warning(s,
                                 "vs-4040: is_reusable: corresponding bit of block %lu does not "
                                 "match required value (bmap==%d, offset==%d) test_bit==%d",
-                                block, bmap, offset, reiserfs_test_le_bit(offset,
-                                                                  SB_AP_BITMAP
-                                                                  (s)[bmap].bh->
-                                                                  b_data));
+                                block, bmap, offset,
+                                reiserfs_test_le_bit(offset, bh->b_data));
 
+               brelse(bh);
                return 0;
        }
+       brelse(bh);
 
        if (bit_value == 0 && block == SB_ROOT_BLOCK(s)) {
                reiserfs_warning(s,
@@ -151,6 +153,7 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
 {
        struct super_block *s = th->t_super;
        struct reiserfs_bitmap_info *bi = &SB_AP_BITMAP(s)[bmap_n];
+       struct buffer_head *bh;
        int end, next;
        int org = *beg;
 
@@ -169,22 +172,28 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
                                 bmap_n);
                return 0;
        }
-       if (buffer_locked(bi->bh)) {
+       bh = bi->bh;
+       get_bh(bh);
+
+       if (buffer_locked(bh)) {
                PROC_INFO_INC(s, scan_bitmap.wait);
-               __wait_on_buffer(bi->bh);
+               __wait_on_buffer(bh);
        }
 
        while (1) {
              cont:
-               if (bi->free_count < min)
+               if (bi->free_count < min) {
+                       brelse(bh);
                        return 0;       // No free blocks in this bitmap
+               }
 
                /* search for a first zero bit -- beggining of a window */
                *beg = reiserfs_find_next_zero_le_bit
-                   ((unsigned long *)(bi->bh->b_data), boundary, *beg);
+                   ((unsigned long *)(bh->b_data), boundary, *beg);
 
                if (*beg + min > boundary) {    /* search for a zero bit fails or the rest of bitmap block
                                                 * cannot contain a zero window of minimum size */
+                       brelse(bh);
                        return 0;
                }
 
@@ -193,7 +202,7 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
                /* first zero bit found; we check next bits */
                for (end = *beg + 1;; end++) {
                        if (end >= *beg + max || end >= boundary
-                           || reiserfs_test_le_bit(end, bi->bh->b_data)) {
+                           || reiserfs_test_le_bit(end, bh->b_data)) {
                                next = end;
                                break;
                        }
@@ -207,12 +216,12 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
                 * (end) points to one bit after the window end */
                if (end - *beg >= min) {        /* it seems we have found window of proper size */
                        int i;
-                       reiserfs_prepare_for_journal(s, bi->bh, 1);
+                       reiserfs_prepare_for_journal(s, bh, 1);
                        /* try to set all blocks used checking are they still free */
                        for (i = *beg; i < end; i++) {
                                /* It seems that we should not check in journal again. */
                                if (reiserfs_test_and_set_le_bit
-                                   (i, bi->bh->b_data)) {
+                                   (i, bh->b_data)) {
                                        /* bit was set by another process
                                         * while we slept in prepare_for_journal() */
                                        PROC_INFO_INC(s, scan_bitmap.stolen);
@@ -224,17 +233,16 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
                                        /* otherwise we clear all bit were set ... */
                                        while (--i >= *beg)
                                                reiserfs_test_and_clear_le_bit
-                                                   (i, bi->bh->b_data);
-                                       reiserfs_restore_prepared_buffer(s,
-                                                                        bi->
-                                                                        bh);
+                                                   (i, bh->b_data);
+                                       reiserfs_restore_prepared_buffer(s, bh);
                                        *beg = org;
                                        /* ... and search again in current block from beginning */
                                        goto cont;
                                }
                        }
                        bi->free_count -= (end - *beg);
-                       journal_mark_dirty(th, s, bi->bh);
+                       journal_mark_dirty(th, s, bh);
+                       brelse(bh);
 
                        /* free block count calculation */
                        reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s),
@@ -383,7 +391,7 @@ static void _reiserfs_free_block(struct reiserfs_transaction_handle *th,
 {
        struct super_block *s = th->t_super;
        struct reiserfs_super_block *rs;
-       struct buffer_head *sbh;
+       struct buffer_head *sbh, *bmbh;
        struct reiserfs_bitmap_info *apbi;
        int nr, offset;
 
@@ -404,16 +412,20 @@ static void _reiserfs_free_block(struct reiserfs_transaction_handle *th,
                return;
        }
 
-       reiserfs_prepare_for_journal(s, apbi[nr].bh, 1);
+       bmbh = apbi[nr].bh;
+       get_bh(bmbh);
+
+       reiserfs_prepare_for_journal(s, bmbh, 1);
 
        /* clear bit for the given block in bit map */
-       if (!reiserfs_test_and_clear_le_bit(offset, apbi[nr].bh->b_data)) {
+       if (!reiserfs_test_and_clear_le_bit(offset, bmbh->b_data)) {
                reiserfs_warning(s, "vs-4080: reiserfs_free_block: "
                                 "free_block (%s:%lu)[dev:blocknr]: bit already cleared",
                                 reiserfs_bdevname(s), block);
        }
        apbi[nr].free_count++;
-       journal_mark_dirty(th, s, apbi[nr].bh);
+       journal_mark_dirty(th, s, bmbh);
+       brelse(bmbh);
 
        reiserfs_prepare_for_journal(s, sbh, 1);
        /* update super block */

diff --git a/fs/reiserfs/resize.c b/fs/reiserfs/resize.c
index 39cc7f4..958b759 100644 (file)
--- a/fs/reiserfs/resize.c
+++ b/fs/reiserfs/resize.c
@@ -22,6 +22,7 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
        int err = 0;
        struct reiserfs_super_block *sb;
        struct reiserfs_bitmap_info *bitmap;
+       struct reiserfs_bitmap_info *info;
        struct reiserfs_bitmap_info *old_bitmap = SB_AP_BITMAP(s);
        struct buffer_head *bh;
        struct reiserfs_transaction_handle th;
@@ -127,16 +128,19 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
                 * transaction begins, and the new bitmaps don't matter if the
                 * transaction fails. */
                for (i = bmap_nr; i < bmap_nr_new; i++) {
-                       bitmap[i].bh = sb_getblk(s, i * s->s_blocksize * 8);
-                       memset(bitmap[i].bh->b_data, 0, sb_blocksize(sb));
-                       reiserfs_test_and_set_le_bit(0, bitmap[i].bh->b_data);
-
-                       set_buffer_uptodate(bitmap[i].bh);
-                       mark_buffer_dirty(bitmap[i].bh);
-                       sync_dirty_buffer(bitmap[i].bh);
+                       bh = sb_getblk(s, i * s->s_blocksize * 8);
+                       get_bh(bh);
+                       memset(bh->b_data, 0, sb_blocksize(sb));
+                       reiserfs_test_and_set_le_bit(0, bh->b_data);
+
+                       set_buffer_uptodate(bh);
+                       mark_buffer_dirty(bh);
+                       sync_dirty_buffer(bh);
                        // update bitmap_info stuff
                        bitmap[i].first_zero_hint = 1;
                        bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
+                       bitmap[i].bh = bh;
+                       brelse(bh);
                }
                /* free old bitmap blocks array */
                SB_AP_BITMAP(s) = bitmap;
@@ -150,30 +154,36 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
        if (err)
                return err;
 
-       /* correct last bitmap blocks in old and new disk layout */
-       reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr - 1].bh, 1);
+       /* Extend old last bitmap block - new blocks have been made available */
+       info = SB_AP_BITMAP(s) + bmap_nr - 1;
+       bh = info->bh;
+       get_bh(bh);
+
+       reiserfs_prepare_for_journal(s, bh, 1);
        for (i = block_r; i < s->s_blocksize * 8; i++)
-               reiserfs_test_and_clear_le_bit(i,
-                                              SB_AP_BITMAP(s)[bmap_nr -
-                                                              1].bh->b_data);
-       SB_AP_BITMAP(s)[bmap_nr - 1].free_count += s->s_blocksize * 8 - block_r;
-       if (!SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint)
-               SB_AP_BITMAP(s)[bmap_nr - 1].first_zero_hint = block_r;
+               reiserfs_test_and_clear_le_bit(i, bh->b_data);
+       info->free_count += s->s_blocksize * 8 - block_r;
+       if (!info->first_zero_hint)
+               info->first_zero_hint = block_r;
+
+       journal_mark_dirty(&th, s, bh);
+       brelse(bh);
 
-       journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr - 1].bh);
+       /* Correct new last bitmap block - It may not be full */
+       info = SB_AP_BITMAP(s) + bmap_nr_new - 1;
+       bh = info->bh;
+       get_bh(bh);
 
-       reiserfs_prepare_for_journal(s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh, 1);
+       reiserfs_prepare_for_journal(s, bh, 1);
        for (i = block_r_new; i < s->s_blocksize * 8; i++)
-               reiserfs_test_and_set_le_bit(i,
-                                            SB_AP_BITMAP(s)[bmap_nr_new -
-                                                            1].bh->b_data);
-       journal_mark_dirty(&th, s, SB_AP_BITMAP(s)[bmap_nr_new - 1].bh);
+               reiserfs_test_and_set_le_bit(i, bh->b_data);
+       journal_mark_dirty(&th, s, bh);
+       brelse(bh);
 
-       SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count -=
-           s->s_blocksize * 8 - block_r_new;
+       info->free_count -= s->s_blocksize * 8 - block_r_new;
        /* Extreme case where last bitmap is the only valid block in itself. */
-       if (!SB_AP_BITMAP(s)[bmap_nr_new - 1].free_count)
-               SB_AP_BITMAP(s)[bmap_nr_new - 1].first_zero_hint = 0;
+       if (!info->free_count)
+               info->first_zero_hint = 0;
        /* update super */
        reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1);
        free_blocks = SB_FREE_BLOCKS(s);