[PATCH] ext2: fix mounts at 16T

[pandora-kernel.git] / fs / ext2 / super.c

diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index ee4ba75..d978d3f 100644 (file)
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -16,7 +16,6 @@
  *        David S. Miller (davem@caip.rutgers.edu), 1995
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/string.h>
 #include <linux/fs.h>
@@ -252,6 +251,44 @@ static struct super_operations ext2_sops = {
 #endif
 };
 
+static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
+{
+       __u32 *objp = vobjp;
+       unsigned long ino = objp[0];
+       __u32 generation = objp[1];
+       struct inode *inode;
+       struct dentry *result;
+
+       if (ino < EXT2_FIRST_INO(sb) && ino != EXT2_ROOT_INO)
+               return ERR_PTR(-ESTALE);
+       if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
+               return ERR_PTR(-ESTALE);
+
+       /* iget isn't really right if the inode is currently unallocated!!
+        * ext2_read_inode currently does appropriate checks, but
+        * it might be "neater" to call ext2_get_inode first and check
+        * if the inode is valid.....
+        */
+       inode = iget(sb, ino);
+       if (inode == NULL)
+               return ERR_PTR(-ENOMEM);
+       if (is_bad_inode(inode) ||
+           (generation && inode->i_generation != generation)) {
+               /* we didn't find the right inode.. */
+               iput(inode);
+               return ERR_PTR(-ESTALE);
+       }
+       /* now to find a dentry.
+        * If possible, get a well-connected one
+        */
+       result = d_alloc_anon(inode);
+       if (!result) {
+               iput(inode);
+               return ERR_PTR(-ENOMEM);
+       }
+       return result;
+}
+
 /* Yes, most of these are left as NULL!!
  * A NULL value implies the default, which works with ext2-like file
  * systems, but can be improved upon.
@@ -259,6 +296,7 @@ static struct super_operations ext2_sops = {
  */
 static struct export_operations ext2_export_ops = {
        .get_parent = ext2_get_parent,
+       .get_dentry = ext2_get_dentry,
 };
 
 static unsigned long get_sb_block(void **data)
@@ -506,17 +544,24 @@ static int ext2_check_descriptors (struct super_block * sb)
        int i;
        int desc_block = 0;
        struct ext2_sb_info *sbi = EXT2_SB(sb);
-       unsigned long block = le32_to_cpu(sbi->s_es->s_first_data_block);
+       unsigned long first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
+       unsigned long last_block;
        struct ext2_group_desc * gdp = NULL;
 
        ext2_debug ("Checking group descriptors");
 
        for (i = 0; i < sbi->s_groups_count; i++)
        {
+               if (i == sbi->s_groups_count - 1)
+                       last_block = le32_to_cpu(sbi->s_es->s_blocks_count) - 1;
+               else
+                       last_block = first_block +
+                               (EXT2_BLOCKS_PER_GROUP(sb) - 1);
+
                if ((i % EXT2_DESC_PER_BLOCK(sb)) == 0)
                        gdp = (struct ext2_group_desc *) sbi->s_group_desc[desc_block++]->b_data;
-               if (le32_to_cpu(gdp->bg_block_bitmap) < block ||
-                   le32_to_cpu(gdp->bg_block_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
+               if (le32_to_cpu(gdp->bg_block_bitmap) < first_block ||
+                   le32_to_cpu(gdp->bg_block_bitmap) > last_block)
                {
                        ext2_error (sb, "ext2_check_descriptors",
                                    "Block bitmap for group %d"
@@ -524,8 +569,8 @@ static int ext2_check_descriptors (struct super_block * sb)
                                    i, (unsigned long) le32_to_cpu(gdp->bg_block_bitmap));
                        return 0;
                }
-               if (le32_to_cpu(gdp->bg_inode_bitmap) < block ||
-                   le32_to_cpu(gdp->bg_inode_bitmap) >= block + EXT2_BLOCKS_PER_GROUP(sb))
+               if (le32_to_cpu(gdp->bg_inode_bitmap) < first_block ||
+                   le32_to_cpu(gdp->bg_inode_bitmap) > last_block)
                {
                        ext2_error (sb, "ext2_check_descriptors",
                                    "Inode bitmap for group %d"
@@ -533,9 +578,9 @@ static int ext2_check_descriptors (struct super_block * sb)
                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_bitmap));
                        return 0;
                }
-               if (le32_to_cpu(gdp->bg_inode_table) < block ||
-                   le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >=
-                   block + EXT2_BLOCKS_PER_GROUP(sb))
+               if (le32_to_cpu(gdp->bg_inode_table) < first_block ||
+                   le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
+                   last_block)
                {
                        ext2_error (sb, "ext2_check_descriptors",
                                    "Inode table for group %d"
@@ -543,7 +588,7 @@ static int ext2_check_descriptors (struct super_block * sb)
                                    i, (unsigned long) le32_to_cpu(gdp->bg_inode_table));
                        return 0;
                }
-               block += EXT2_BLOCKS_PER_GROUP(sb);
+               first_block += EXT2_BLOCKS_PER_GROUP(sb);
                gdp++;
        }
        return 1;
@@ -776,7 +821,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
        if (EXT2_INODE_SIZE(sb) == 0)
                goto cantfind_ext2;
        sbi->s_inodes_per_block = sb->s_blocksize / EXT2_INODE_SIZE(sb);
-       if (sbi->s_inodes_per_block == 0)
+       if (sbi->s_inodes_per_block == 0 || sbi->s_inodes_per_group == 0)
                goto cantfind_ext2;
        sbi->s_itb_per_group = sbi->s_inodes_per_group /
                                        sbi->s_inodes_per_block;
@@ -823,10 +868,9 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 
        if (EXT2_BLOCKS_PER_GROUP(sb) == 0)
                goto cantfind_ext2;
-       sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) -
-                                       le32_to_cpu(es->s_first_data_block) +
-                                      EXT2_BLOCKS_PER_GROUP(sb) - 1) /
-                                      EXT2_BLOCKS_PER_GROUP(sb);
+       sbi->s_groups_count = ((le32_to_cpu(es->s_blocks_count) -
+                               le32_to_cpu(es->s_first_data_block) - 1)
+                                       / EXT2_BLOCKS_PER_GROUP(sb)) + 1;
        db_count = (sbi->s_groups_count + EXT2_DESC_PER_BLOCK(sb) - 1) /
                   EXT2_DESC_PER_BLOCK(sb);
        sbi->s_group_desc = kmalloc (db_count * sizeof (struct buffer_head *), GFP_KERNEL);
@@ -854,7 +898,6 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
        }
        if (!ext2_check_descriptors (sb)) {
                printk ("EXT2-fs: group descriptors corrupted!\n");
-               db_count = i;
                goto failed_mount2;
        }
        sbi->s_gdb_count = db_count;
@@ -1157,7 +1200,7 @@ static ssize_t ext2_quota_write(struct super_block *sb, int type,
        struct buffer_head tmp_bh;
        struct buffer_head *bh;
 
-       mutex_lock(&inode->i_mutex);
+       mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
        while (towrite > 0) {
                tocopy = sb->s_blocksize - offset < towrite ?
                                sb->s_blocksize - offset : towrite;