In its early life, reiserfs had an evolving s_max_bytes. It started out at 4 GB, then was raised to MAX_LFS_FILESIZE, then dropped to 2 TiB when it was observed that struct stat only had a 32-bit st_blocks field. Since then, both the kernel and glibc have evolved as well and now both support 64-bit st_blocks. Applications that can't deal with these ranges are assumed to be "legacy" or "broken." File systems now routinely support file sizes much larger than can be represented by 2^32 * 512. But we never revisited that limitation. ReiserFS has always been able to support larger file sizes (up to 16 TiB, in fact), but the s_max_bytes limitation has prevented that. This patch adds a max_file_offset helper to set s_max_bytes to a more appropriate value. I noticed that XFS adjusts the limit based on the CPU but I'd prefer to err on the side of compatibility and place the limit at the smaller of the 32-bit MAX_LFS_FILESIZE and the maximum supported by the file system. At a 4k block size, this is conveniently also the advertised maximum file size of reiserfs. This bug is tracked at: https://bugzilla.novell.com/show_bug.cgi?id=592100 Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx> --- fs/reiserfs/super.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -1309,6 +1309,18 @@ out_err: return err; } +static inline loff_t +reiserfs_max_file_offset(struct super_block *sb) +{ + /* Limited by stat_data->sd_blocks, 2^32-1 blocks */ + loff_t fs_max = (sb->s_blocksize << 32) - sb->s_blocksize; + + /* Limited by 32-bit MAX_LFS_FILESIZE */ + loff_t page_cache_max = (((u64)PAGE_CACHE_SIZE << 31)-1); + + return min(fs_max, page_cache_max); +} + static int read_super_block(struct super_block *s, int offset) { struct buffer_head *bh; @@ -1398,10 +1410,7 @@ static int read_super_block(struct super s->dq_op = &reiserfs_quota_operations; #endif - /* new format is limited by the 32 bit wide i_blocks field, want to - ** be one full block below that. - */ - s->s_maxbytes = (512LL << 32) - s->s_blocksize; + s->s_maxbytes = reiserfs_max_file_offset(s); return 0; } -- To unsubscribe from this list: send the line "unsubscribe reiserfs-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
