Re: btrfs: obtain block checksums from user space

2015-10-01 Thread David Sterba
On Thu, Sep 24, 2015 at 09:06:32PM +0300, Matwey V. Kornilov wrote: > I would like to read the list of the checksums for the specific file > stored onto btrfs filesystem. I think I could use the checksums in the > manner like rsync does, but safe both CPU (because csums are already > calculated

Re: btrfs: obtain block checksums from user space

2015-09-28 Thread Calvin Walton
On Mon, 2015-09-28 at 23:16 +, Hugo Mills wrote: > On Mon, Sep 28, 2015 at 07:11:51PM -0400, Calvin Walton wrote: > > > > The problem with trying to use btrfs checksums to compare two > > different > > files is that the blocks might not match up, if only due to > > fragmentation. E.g., the

Re: btrfs: obtain block checksums from user space

2015-09-28 Thread Calvin Walton
On Thu, 2015-09-24 at 21:48 +0300, Matwey V. Kornilov wrote: > 2015-09-24 21:35 GMT+03:00 Austin S Hemmelgarn > : > > On 2015-09-24 14:06, Matwey V. Kornilov wrote: > > It's worth noting that the way btrfs does checksums isn't per-file, > > it's > > per-block. This means

Re: btrfs: obtain block checksums from user space

2015-09-28 Thread Hugo Mills
On Mon, Sep 28, 2015 at 07:11:51PM -0400, Calvin Walton wrote: > On Thu, 2015-09-24 at 21:48 +0300, Matwey V. Kornilov wrote: > > 2015-09-24 21:35 GMT+03:00 Austin S Hemmelgarn > > : > > > On 2015-09-24 14:06, Matwey V. Kornilov wrote: > > > > It's worth noting that the way

Re: btrfs: obtain block checksums from user space

2015-09-24 Thread Austin S Hemmelgarn
On 2015-09-24 14:48, Matwey V. Kornilov wrote: 2015-09-24 21:35 GMT+03:00 Austin S Hemmelgarn : On 2015-09-24 14:06, Matwey V. Kornilov wrote: Hello, I would like to read the list of the checksums for the specific file stored onto btrfs filesystem. I think I could use

Re: btrfs: obtain block checksums from user space

2015-09-24 Thread Matwey V. Kornilov
2015-09-24 21:35 GMT+03:00 Austin S Hemmelgarn : > On 2015-09-24 14:06, Matwey V. Kornilov wrote: >> >> >> Hello, >> >> I would like to read the list of the checksums for the specific file >> stored onto btrfs filesystem. I think I could use the checksums in the >> manner

btrfs: obtain block checksums from user space

2015-09-24 Thread Matwey V. Kornilov
Hello, I would like to read the list of the checksums for the specific file stored onto btrfs filesystem. I think I could use the checksums in the manner like rsync does, but safe both CPU (because csums are already calculated for the file) and I/O (because I don't need to reread all the file

Re: btrfs: obtain block checksums from user space

2015-09-24 Thread Austin S Hemmelgarn
On 2015-09-24 14:06, Matwey V. Kornilov wrote: Hello, I would like to read the list of the checksums for the specific file stored onto btrfs filesystem. I think I could use the checksums in the manner like rsync does, but safe both CPU (because csums are already calculated for the file) and