On Fri, May 21, 2010 at 10:17 AM, Tim Shearouse <t.shearouse@xxxxxxxxx> wrote: > On Thu, May 20, 2010 at 2:10 PM, Jeff Mahoney <jeffm@xxxxxxxx> wrote: >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> On 05/19/2010 06:00 PM, Edward Shishkin wrote: >>> Leonardo Chiquitto wrote: >>>> 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? >>> >>> I wouldn't rely on this. Reiserfsprogs also should be aware >>> of the new limits. It's all long.. >> >> I certainly hope not. Things would be broken already. The 2 TB limit is >> 2048 * 2^32. >> >> - -Jeff >> >>>> We're hitting the 2TB >>>> file limit here and this patch resolves the problem. >>>> >>>> Thanks, >>>> Leonardo >> - -- >> Jeff Mahoney >> SUSE Labs > > I do not believe this patch will cause problems. As you mention, > ReiserFS was intended to support a max 16TB filesize. > > Edward, it looks to me as though reiserfsprogs will be aware of the > new limits, unless I am missing something (it does not have its own > method for accessing the super block somewhere, correct?). Hello, I apologize for insisting here but it's really important for us to get this fixed upstream. Please, can someone submit it for 2.6.35 or, if the patch is not a good idea, give a little insight on what's wrong? 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
