summaryrefslogtreecommitdiffstats
path: root/fs/xfs/xfs_super.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/xfs/xfs_super.c')
-rw-r--r--fs/xfs/xfs_super.c48
1 files changed, 21 insertions, 27 deletions
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index d9ae27ddf253..760901783944 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -193,32 +193,6 @@ 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
@@ -1424,6 +1398,26 @@ 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;
@@ -1435,7 +1429,7 @@ 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;