Leonardo Chiquitto wrote:
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:
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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
I guess nobody will accept this to 2.6.35..
We only can push it to -mm with the following proceeding
from the akpm's side..
or,
if the patch is not a good idea, give a little insight on what's wrong?
Jeff, did you have any chances to run and fsck this on 32 and 64-bit
machines?
Thanks,
Edward.
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