On Wed, May 19, 2010 at 4:22 PM, Jeff Mahoney <jeffm@xxxxxxxx> wrote: > 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. > > Update: This version properly extends PAGE_SIZE_CACHE so the math works > on 32-bit systems. > > 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 = ((u64)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; > } Hello ReiserFS developers, Any chance to have this patch submitted to 2.6.35? We're hitting the 2TB file limit here and this patch resolves the problem. Thanks, Leonardo -- 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
