kcore: add _text to KCORE_TEXT
[safe/jmp/linux-2.6] / fs / ext2 / balloc.c
index 377ad17..e8766a3 100644 (file)
@@ -13,6 +13,7 @@
 
 #include "ext2.h"
 #include <linux/quotaops.h>
+#include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/buffer_head.h>
 #include <linux/capability.h>
@@ -69,9 +70,53 @@ struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
        return desc + offset;
 }
 
+static int ext2_valid_block_bitmap(struct super_block *sb,
+                                       struct ext2_group_desc *desc,
+                                       unsigned int block_group,
+                                       struct buffer_head *bh)
+{
+       ext2_grpblk_t offset;
+       ext2_grpblk_t next_zero_bit;
+       ext2_fsblk_t bitmap_blk;
+       ext2_fsblk_t group_first_block;
+
+       group_first_block = ext2_group_first_block_no(sb, block_group);
+
+       /* check whether block bitmap block number is set */
+       bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+       offset = bitmap_blk - group_first_block;
+       if (!ext2_test_bit(offset, bh->b_data))
+               /* bad block bitmap */
+               goto err_out;
+
+       /* check whether the inode bitmap block number is set */
+       bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
+       offset = bitmap_blk - group_first_block;
+       if (!ext2_test_bit(offset, bh->b_data))
+               /* bad block bitmap */
+               goto err_out;
+
+       /* check whether the inode table block number is set */
+       bitmap_blk = le32_to_cpu(desc->bg_inode_table);
+       offset = bitmap_blk - group_first_block;
+       next_zero_bit = ext2_find_next_zero_bit(bh->b_data,
+                               offset + EXT2_SB(sb)->s_itb_per_group,
+                               offset);
+       if (next_zero_bit >= offset + EXT2_SB(sb)->s_itb_per_group)
+               /* good bitmap for inode tables */
+               return 1;
+
+err_out:
+       ext2_error(sb, __func__,
+                       "Invalid block bitmap - "
+                       "block_group = %d, block = %lu",
+                       block_group, bitmap_blk);
+       return 0;
+}
+
 /*
- * Read the bitmap for a given block_group, reading into the specified 
- * slot in the superblock's bitmap cache.
+ * Read the bitmap for a given block_group,and validate the
+ * bits for block/inode/inode tables are set in the bitmaps
  *
  * Return buffer_head on success or NULL in case of failure.
  */
@@ -80,17 +125,37 @@ read_block_bitmap(struct super_block *sb, unsigned int block_group)
 {
        struct ext2_group_desc * desc;
        struct buffer_head * bh = NULL;
-       
-       desc = ext2_get_group_desc (sb, block_group, NULL);
+       ext2_fsblk_t bitmap_blk;
+
+       desc = ext2_get_group_desc(sb, block_group, NULL);
        if (!desc)
-               goto error_out;
-       bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap));
-       if (!bh)
-               ext2_error (sb, "read_block_bitmap",
+               return NULL;
+       bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+       bh = sb_getblk(sb, bitmap_blk);
+       if (unlikely(!bh)) {
+               ext2_error(sb, __func__,
+                           "Cannot read block bitmap - "
+                           "block_group = %d, block_bitmap = %u",
+                           block_group, le32_to_cpu(desc->bg_block_bitmap));
+               return NULL;
+       }
+       if (likely(bh_uptodate_or_lock(bh)))
+               return bh;
+
+       if (bh_submit_read(bh) < 0) {
+               brelse(bh);
+               ext2_error(sb, __func__,
                            "Cannot read block bitmap - "
                            "block_group = %d, block_bitmap = %u",
                            block_group, le32_to_cpu(desc->bg_block_bitmap));
-error_out:
+               return NULL;
+       }
+
+       ext2_valid_block_bitmap(sb, desc, block_group, bh);
+       /*
+        * file system mounted not to panic on error, continue with corrupt
+        * bitmap
+        */
        return bh;
 }
 
@@ -182,11 +247,10 @@ restart:
                prev = rsv;
        }
        printk("Window map complete.\n");
-       if (bad)
-               BUG();
+       BUG_ON(bad);
 }
 #define rsv_window_dump(root, verbose) \
-       __rsv_window_dump((root), (verbose), __FUNCTION__)
+       __rsv_window_dump((root), (verbose), __func__)
 #else
 #define rsv_window_dump(root, verbose) do {} while (0)
 #endif
@@ -474,16 +538,18 @@ do_more:
            in_range (block, le32_to_cpu(desc->bg_inode_table),
                      sbi->s_itb_per_group) ||
            in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table),
-                     sbi->s_itb_per_group))
+                     sbi->s_itb_per_group)) {
                ext2_error (sb, "ext2_free_blocks",
                            "Freeing blocks in system zones - "
                            "Block = %lu, count = %lu",
                            block, count);
+               goto error_return;
+       }
 
        for (i = 0, group_freed = 0; i < count; i++) {
                if (!ext2_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
                                                bit + i, bitmap_bh->b_data)) {
-                       ext2_error(sb, __FUNCTION__,
+                       ext2_error(sb, __func__,
                                "bit already cleared for block %lu", block + i);
                } else {
                        group_freed++;
@@ -505,7 +571,7 @@ do_more:
 error_return:
        brelse(bitmap_bh);
        release_blocks(sb, freed);
-       DQUOT_FREE_BLOCK(inode, freed);
+       dquot_free_block(inode, freed);
 }
 
 /**
@@ -1128,7 +1194,7 @@ static int ext2_has_free_blocks(struct ext2_sb_info *sbi)
        free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
        root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count);
        if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
-               sbi->s_resuid != current->fsuid &&
+               sbi->s_resuid != current_fsuid() &&
                (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) {
                return 0;
        }
@@ -1171,6 +1237,7 @@ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal,
        unsigned short windowsz = 0;
        unsigned long ngroups;
        unsigned long num = *count;
+       int ret;
 
        *errp = -ENOSPC;
        sb = inode->i_sb;
@@ -1182,8 +1249,9 @@ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal,
        /*
         * Check quota for allocation of this block.
         */
-       if (DQUOT_ALLOC_BLOCK(inode, num)) {
-               *errp = -EDQUOT;
+       ret = dquot_alloc_block(inode, num);
+       if (ret) {
+               *errp = ret;
                return 0;
        }
 
@@ -1230,6 +1298,7 @@ retry_alloc:
         * turn off reservation for this allocation
         */
        if (my_rsv && (free_blocks < windowsz)
+               && (free_blocks > 0)
                && (rsv_is_empty(&my_rsv->rsv_window)))
                my_rsv = NULL;
 
@@ -1250,8 +1319,8 @@ retry_alloc:
        smp_rmb();
 
        /*
-        * Now search the rest of the groups.  We assume that 
-        * i and gdp correctly point to the last group visited.
+        * Now search the rest of the groups.  We assume that
+        * group_no and gdp correctly point to the last group visited.
         */
        for (bgi = 0; bgi < ngroups; bgi++) {
                group_no++;
@@ -1263,11 +1332,17 @@ retry_alloc:
 
                free_blocks = le16_to_cpu(gdp->bg_free_blocks_count);
                /*
+                * skip this group (and avoid loading bitmap) if there
+                * are no free blocks
+                */
+               if (!free_blocks)
+                       continue;
+               /*
                 * skip this group if the number of
                 * free blocks is less than half of the reservation
                 * window size.
                 */
-               if (free_blocks <= (windowsz/2))
+               if (my_rsv && (free_blocks <= (windowsz/2)))
                        continue;
 
                brelse(bitmap_bh);
@@ -1311,11 +1386,18 @@ allocated:
            in_range(ret_block, le32_to_cpu(gdp->bg_inode_table),
                      EXT2_SB(sb)->s_itb_per_group) ||
            in_range(ret_block + num - 1, le32_to_cpu(gdp->bg_inode_table),
-                     EXT2_SB(sb)->s_itb_per_group))
+                     EXT2_SB(sb)->s_itb_per_group)) {
                ext2_error(sb, "ext2_new_blocks",
                            "Allocating block in system zone - "
                            "blocks from "E2FSBLK", length %lu",
                            ret_block, num);
+               /*
+                * ext2_try_to_allocate marked the blocks we allocated as in
+                * use.  So we may want to selectively mark some of the blocks
+                * as free
+                */
+               goto retry_alloc;
+       }
 
        performed_allocation = 1;
 
@@ -1336,7 +1418,7 @@ allocated:
 
        *errp = 0;
        brelse(bitmap_bh);
-       DQUOT_FREE_BLOCK(inode, *count-num);
+       dquot_free_block(inode, *count-num);
        *count = num;
        return ret_block;
 
@@ -1347,7 +1429,7 @@ out:
         * Undo the block allocation
         */
        if (!performed_allocation)
-               DQUOT_FREE_BLOCK(inode, *count);
+               dquot_free_block(inode, *count);
        brelse(bitmap_bh);
        return 0;
 }
@@ -1466,9 +1548,6 @@ int ext2_bg_has_super(struct super_block *sb, int group)
  */
 unsigned long ext2_bg_num_gdb(struct super_block *sb, int group)
 {
-       if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
-           !ext2_group_sparse(group))
-               return 0;
-       return EXT2_SB(sb)->s_gdb_count;
+       return ext2_bg_has_super(sb, group) ? EXT2_SB(sb)->s_gdb_count : 0;
 }