Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

[linux.git] / fs / xfs / xfs_super.c

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index b03d82fcf0112a11b6593f67f4546045189ec339..2094386af8aca045021964dce6a8295f4ef3ef34 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -188,32 +188,6 @@ xfs_fs_show_options(
        return 0;
 }
 
-static uint64_t
-xfs_max_file_offset(
-       unsigned int            blockshift)
-{
-       unsigned int            pagefactor = 1;
-       unsigned int            bitshift = BITS_PER_LONG - 1;
-
-       /* Figure out maximum filesize, on Linux this can depend on
-        * the filesystem blocksize (on 32 bit platforms).
-        * __block_write_begin does this in an [unsigned] long long...
-        *      page->index << (PAGE_SHIFT - bbits)
-        * So, for page sized blocks (4K on 32 bit platforms),
-        * this wraps at around 8Tb (hence MAX_LFS_FILESIZE which is
-        *      (((u64)PAGE_SIZE << (BITS_PER_LONG-1))-1)
-        * but for smaller blocksizes it is less (bbits = log2 bsize).
-        */
-
-#if BITS_PER_LONG == 32
-       ASSERT(sizeof(sector_t) == 8);
-       pagefactor = PAGE_SIZE;
-       bitshift = BITS_PER_LONG;
-#endif
-
-       return (((uint64_t)pagefactor) << bitshift) - 1;
-}
-
 /*
  * Set parameters for inode allocation heuristics, taking into account
  * filesystem size and inode32/inode64 mount options; i.e. specifically
@@ -1419,6 +1393,26 @@ xfs_fc_fill_super(
        if (error)
                goto out_free_sb;
 
+       /*
+        * XFS block mappings use 54 bits to store the logical block offset.
+        * This should suffice to handle the maximum file size that the VFS
+        * supports (currently 2^63 bytes on 64-bit and ULONG_MAX << PAGE_SHIFT
+        * bytes on 32-bit), but as XFS and VFS have gotten the s_maxbytes
+        * calculation wrong on 32-bit kernels in the past, we'll add a WARN_ON
+        * to check this assertion.
+        *
+        * Avoid integer overflow by comparing the maximum bmbt offset to the
+        * maximum pagecache offset in units of fs blocks.
+        */
+       if (XFS_B_TO_FSBT(mp, MAX_LFS_FILESIZE) > XFS_MAX_FILEOFF) {
+               xfs_warn(mp,
+"MAX_LFS_FILESIZE block offset (%llu) exceeds extent map maximum (%llu)!",
+                        XFS_B_TO_FSBT(mp, MAX_LFS_FILESIZE),
+                        XFS_MAX_FILEOFF);
+               error = -EINVAL;
+               goto out_free_sb;
+       }
+
        error = xfs_filestream_mount(mp);
        if (error)
                goto out_free_sb;
@@ -1430,7 +1424,7 @@ xfs_fc_fill_super(
        sb->s_magic = XFS_SUPER_MAGIC;
        sb->s_blocksize = mp->m_sb.sb_blocksize;
        sb->s_blocksize_bits = ffs(sb->s_blocksize) - 1;
-       sb->s_maxbytes = xfs_max_file_offset(sb->s_blocksize_bits);
+       sb->s_maxbytes = MAX_LFS_FILESIZE;
        sb->s_max_links = XFS_MAXLINK;
        sb->s_time_gran = 1;
        sb->s_time_min = S32_MIN;