Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e2b4657453c0d5571bd3c7256585c486ed42d364
Commit:     e2b4657453c0d5571bd3c7256585c486ed42d364
Parent:     19295529db35381d46dbaf246f69b4e3b3393996
Author:     Eric Sandeen <[EMAIL PROTECTED]>
AuthorDate: Mon Jan 28 23:58:27 2008 -0500
Committer:  Theodore Ts'o <[EMAIL PROTECTED]>
CommitDate: Mon Jan 28 23:58:27 2008 -0500

    ext4: store maxbytes for bitmapped  files and return EFBIG as appropriate
    
    Calculate & store the max offset for bitmapped files, and
    catch too-large seeks, truncates, and writes in ext4, shortening
    or rejecting as appropriate.
    
    Signed-off-by: Eric Sandeen <[EMAIL PROTECTED]>
---
 fs/ext4/file.c             |   19 ++++++++++++++++++-
 fs/ext4/inode.c            |   16 +++++++++++++++-
 fs/ext4/super.c            |    1 +
 include/linux/ext4_fs_sb.h |    1 +
 4 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 1a81cd6..a6b2aa1 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -56,8 +56,25 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
        ssize_t ret;
        int err;
 
-       ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+       /*
+        * If we have encountered a bitmap-format file, the size limit
+        * is smaller than s_maxbytes, which is for extent-mapped files.
+        */
+
+       if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
+               struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+               size_t length = iov_length(iov, nr_segs);
 
+               if (pos > sbi->s_bitmap_maxbytes)
+                       return -EFBIG;
+
+               if (pos + length > sbi->s_bitmap_maxbytes) {
+                       nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
+                                             sbi->s_bitmap_maxbytes - pos);
+               }
+       }
+
+       ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
        /*
         * Skip flushing if there was an error, or if nothing was written.
         */
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9cf8572..eaace13 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -314,7 +314,10 @@ static int ext4_block_to_path(struct inode *inode,
                offsets[n++] = i_block & (ptrs - 1);
                final = ptrs;
        } else {
-               ext4_warning(inode->i_sb, "ext4_block_to_path", "block > big");
+               ext4_warning(inode->i_sb, "ext4_block_to_path",
+                               "block %u > max",
+                               i_block + direct_blocks +
+                               indirect_blocks + double_blocks);
        }
        if (boundary)
                *boundary = final - 1 - (i_block & (ptrs - 1));
@@ -3092,6 +3095,17 @@ int ext4_setattr(struct dentry *dentry, struct iattr 
*attr)
                ext4_journal_stop(handle);
        }
 
+       if (attr->ia_valid & ATTR_SIZE) {
+               if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
+                       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+                       if (attr->ia_size > sbi->s_bitmap_maxbytes) {
+                               error = -EFBIG;
+                               goto err_out;
+                       }
+               }
+       }
+
        if (S_ISREG(inode->i_mode) &&
            attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
                handle_t *handle;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index c79e46b..0931831 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1922,6 +1922,7 @@ static int ext4_fill_super (struct super_block *sb, void 
*data, int silent)
                }
        }
 
+       sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits);
        sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
 
        if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
diff --git a/include/linux/ext4_fs_sb.h b/include/linux/ext4_fs_sb.h
index f15821c..38a47ec 100644
--- a/include/linux/ext4_fs_sb.h
+++ b/include/linux/ext4_fs_sb.h
@@ -38,6 +38,7 @@ struct ext4_sb_info {
        ext4_group_t s_groups_count;    /* Number of groups in the fs */
        unsigned long s_overhead_last;  /* Last calculated overhead */
        unsigned long s_blocks_last;    /* Last seen block count */
+       loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
        struct buffer_head * s_sbh;     /* Buffer containing the super block */
        struct ext4_super_block * s_es; /* Pointer to the super block in the 
buffer */
        struct buffer_head ** s_group_desc;
-
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