Re: [Request for review] [RFC] Add label support for snapshots and subvols
On Mon, Nov 05, 2012 at 03:24:48PM +0800, Anand Jain wrote: featurexattr btrfs-kernel-way [1] NoYes [2] NoYes [3] Yes No [1]. Ability to read subvol label without mount It is possible to read it offline, one can traverse the data structures the same way as from kernel, ie root_tree - subovlume fs_tree - root directory item - xattr item. [2]. Full-ability to log and track the property when it is modified What is expected to happen when the label changes? I understand that somebody may change the xattr value silently, but let's say this is changed through kernel -- do you intend to prohibit any changes or issue some notification or whatever? [3]. risk-free patch ? No patch is risk free :) but yes, xattrs use an established and tested infrastruture. davdi -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Request for review] [RFC] Add label support for snapshots and subvols
Thanks for all the comments and inputs. featurexattr btrfs-kernel-way [1] NoYes [2] NoYes [3] Yes No [1]. Ability to read subvol label without mount [2]. Full-ability to log and track the property when it is modified [3]. risk-free patch ? Any comments on why not the btrfs-kernel-way and a review of the patch ? Thanks -Anand On 11/02/2012 06:49 AM, Fajar A. Nugraha wrote: On Fri, Nov 2, 2012 at 5:32 AM, Hugo Mills h...@carfax.org.uk wrote: On Fri, Nov 02, 2012 at 05:28:01AM +0700, Fajar A. Nugraha wrote: On Fri, Nov 2, 2012 at 5:16 AM, cwillu cwi...@cwillu.com wrote: btrfs fi label -t /btrfs/snap1-sv1 Prod-DB-sand-box-testing Why is this better than: # btrfs su snap /btrfs/Prod-DB /btrfs/Prod-DB-sand-box-testing # mv /btrfs/Prod-DB-sand-box-testing /btrfs/Prod-DB-production-test # ls /btrfs/ Prod-DB Prod-DB-production-test ... because it would mean possibilty to decouple subvol name from whatever-data-you-need (in this case, a label). My request, though, is to just implement properties, and USER properties, like what we have in zfs. This seems to be a cleaner, saner approach. For example, this is on Ubutu + zfsonlinux: # zfs create rpool/u # zfs set user:label=Some test filesystem rpool/u # zfs get creation,user:label rpool/u NAME PROPERTYVALUE SOURCE rpool/u creationFri Nov 2 5:24 2012 - rpool/u user:label Some test filesystem local Don't we already have an equivalent to that with user xattrs? Hugo. Anand did say one way to implement the label is by using attr, so +1 from me for that approach. -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Request for review] [RFC] Add label support for snapshots and subvols
Below is a demo of this new feature. btrfs fi label -t /btrfs/sv1 Prod-DB btrfs fi label -t /btrfs/sv1 Prod-DB btrfs su snap /btrfs/sv1 /btrfs/snap1-sv1 Create a snapshot of '/btrfs/sv1' in '/btrfs/snap1-sv1' btrfs fi label -t /btrfs/snap1-sv1 btrfs fi label -t /btrfs/snap1-sv1 Prod-DB-sand-box-testing btrfs fi label -t /btrfs/snap1-sv1 Prod-DB-sand-box-testing Why is this better than: # btrfs su snap /btrfs/Prod-DB /btrfs/Prod-DB-sand-box-testing # mv /btrfs/Prod-DB-sand-box-testing /btrfs/Prod-DB-production-test # ls /btrfs/ Prod-DB Prod-DB-production-test -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Request for review] [RFC] Add label support for snapshots and subvols
On Fri, Nov 2, 2012 at 5:16 AM, cwillu cwi...@cwillu.com wrote: btrfs fi label -t /btrfs/snap1-sv1 Prod-DB-sand-box-testing Why is this better than: # btrfs su snap /btrfs/Prod-DB /btrfs/Prod-DB-sand-box-testing # mv /btrfs/Prod-DB-sand-box-testing /btrfs/Prod-DB-production-test # ls /btrfs/ Prod-DB Prod-DB-production-test ... because it would mean possibilty to decouple subvol name from whatever-data-you-need (in this case, a label). My request, though, is to just implement properties, and USER properties, like what we have in zfs. This seems to be a cleaner, saner approach. For example, this is on Ubutu + zfsonlinux: # zfs create rpool/u # zfs set user:label=Some test filesystem rpool/u # zfs get creation,user:label rpool/u NAME PROPERTYVALUE SOURCE rpool/u creationFri Nov 2 5:24 2012 - rpool/u user:label Some test filesystem local More info about zfs user properties here: http://docs.oracle.com/cd/E19082-01/817-2271/gdrcw/index.html -- Fajar -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Request for review] [RFC] Add label support for snapshots and subvols
On Fri, Nov 02, 2012 at 05:28:01AM +0700, Fajar A. Nugraha wrote: On Fri, Nov 2, 2012 at 5:16 AM, cwillu cwi...@cwillu.com wrote: btrfs fi label -t /btrfs/snap1-sv1 Prod-DB-sand-box-testing Why is this better than: # btrfs su snap /btrfs/Prod-DB /btrfs/Prod-DB-sand-box-testing # mv /btrfs/Prod-DB-sand-box-testing /btrfs/Prod-DB-production-test # ls /btrfs/ Prod-DB Prod-DB-production-test ... because it would mean possibilty to decouple subvol name from whatever-data-you-need (in this case, a label). My request, though, is to just implement properties, and USER properties, like what we have in zfs. This seems to be a cleaner, saner approach. For example, this is on Ubutu + zfsonlinux: # zfs create rpool/u # zfs set user:label=Some test filesystem rpool/u # zfs get creation,user:label rpool/u NAME PROPERTYVALUE SOURCE rpool/u creationFri Nov 2 5:24 2012 - rpool/u user:label Some test filesystem local Don't we already have an equivalent to that with user xattrs? Hugo. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- I spent most of my money on drink, women and fast cars. The --- rest I wasted. -- James Hunt signature.asc Description: Digital signature
Re: [Request for review] [RFC] Add label support for snapshots and subvols
On Fri, Nov 2, 2012 at 5:32 AM, Hugo Mills h...@carfax.org.uk wrote: On Fri, Nov 02, 2012 at 05:28:01AM +0700, Fajar A. Nugraha wrote: On Fri, Nov 2, 2012 at 5:16 AM, cwillu cwi...@cwillu.com wrote: btrfs fi label -t /btrfs/snap1-sv1 Prod-DB-sand-box-testing Why is this better than: # btrfs su snap /btrfs/Prod-DB /btrfs/Prod-DB-sand-box-testing # mv /btrfs/Prod-DB-sand-box-testing /btrfs/Prod-DB-production-test # ls /btrfs/ Prod-DB Prod-DB-production-test ... because it would mean possibilty to decouple subvol name from whatever-data-you-need (in this case, a label). My request, though, is to just implement properties, and USER properties, like what we have in zfs. This seems to be a cleaner, saner approach. For example, this is on Ubutu + zfsonlinux: # zfs create rpool/u # zfs set user:label=Some test filesystem rpool/u # zfs get creation,user:label rpool/u NAME PROPERTYVALUE SOURCE rpool/u creationFri Nov 2 5:24 2012 - rpool/u user:label Some test filesystem local Don't we already have an equivalent to that with user xattrs? Hugo. Anand did say one way to implement the label is by using attr, so +1 from me for that approach. -- Fajar -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Request for review] [RFC] Add label support for snapshots and subvols
On 11/01/2012 11:28 PM, Fajar A. Nugraha wrote: On Fri, Nov 2, 2012 at 5:16 AM, cwillu cwi...@cwillu.com wrote: btrfs fi label -t /btrfs/snap1-sv1 Prod-DB-sand-box-testing Why is this better than: # btrfs su snap /btrfs/Prod-DB /btrfs/Prod-DB-sand-box-testing # mv /btrfs/Prod-DB-sand-box-testing /btrfs/Prod-DB-production-test # ls /btrfs/ Prod-DB Prod-DB-production-test ... because it would mean possibilty to decouple subvol name from whatever-data-you-need (in this case, a label). Could you elaborate how this solution is different from using xattr ? I think also that these labels could be changed (like xattr). ? These info should be associated to the inode of the subvolume root. We could use a specific name in the system namespace, like system.btrfslabel even tough I didn't see any advantage to using the user namespace... -- gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
