On 2011-07-25 10:38, Myklebust, Trond wrote: >> -----Original Message----- >> From: Benny Halevy [mailto:bhalevy@xxxxxxxxxx] >> Sent: Monday, July 25, 2011 10:31 AM >> To: Jim Rees >> Cc: Myklebust, Trond; linux-nfs@xxxxxxxxxxxxxxx; peter honeyman >> Subject: Re: [PATCH v2 07/25] pnfsblock: add blocklayout Kconfig >> option, Makefile, and stubs >> >> On 2011-07-21 15:34, Jim Rees wrote: >>> From: Fred Isaman <iisaman@xxxxxxxxxxxxxx> >>> >>> Define a configuration variable to enable/disable compilation of the >>> block driver code. >>> >>> Add the minimal structure for a pnfs block layout driver, and empty >>> list-heads that will hold the extent data >>> >>> [pnfsblock: make NFS_V4_1 select PNFS_BLOCK] >>> Signed-off-by: Peng Tao <peng_tao@xxxxxxx> >>> Signed-off-by: Fred Isaman <iisaman@xxxxxxxxxxxxxx> >>> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx> >>> [pnfs-block: fix CONFIG_PNFS_BLOCK dependencies] >>> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx> >>> Signed-off-by: Benny Halevy <benny@xxxxxxxxxx> >>> [pnfsblock: SQUASHME: port block layout code] >>> Signed-off-by: Peng Tao <peng_tao@xxxxxxx> >>> [pnfsblock: SQUASHME: adjust to API change] >>> Signed-off-by: Fred Isaman <iisaman@xxxxxxxxxxxxxx> >>> [pnfs: move pnfs_layout_type inline in nfs_inode] >>> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx> >>> [blocklayout: encode_layoutcommit implementation] >>> Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx> >>> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx> >>> Signed-off-by: Benny Halevy <benny@xxxxxxxxxx> >>> [pnfsblock: layout alloc and free] >>> Signed-off-by: Fred Isaman <iisaman@xxxxxxxxxxxxxx> >>> [pnfs: move pnfs_layout_type inline in nfs_inode] >>> Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx> >>> Signed-off-by: Benny Halevy <benny@xxxxxxxxxx> >>> [pnfsblock: define module alias] >>> Signed-off-by: Peng Tao <peng_tao@xxxxxxx> >>> --- >>> fs/nfs/Kconfig | 8 ++- >>> fs/nfs/Makefile | 1 + >>> fs/nfs/blocklayout/Makefile | 5 + >>> fs/nfs/blocklayout/blocklayout.c | 175 >> ++++++++++++++++++++++++++++++++++++++ >>> fs/nfs/blocklayout/blocklayout.h | 91 ++++++++++++++++++++ >>> 5 files changed, 279 insertions(+), 1 deletions(-) >>> create mode 100644 fs/nfs/blocklayout/Makefile >>> create mode 100644 fs/nfs/blocklayout/blocklayout.c >>> create mode 100644 fs/nfs/blocklayout/blocklayout.h >>> >>> diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig >>> index 2cde5d9..be02077 100644 >>> --- a/fs/nfs/Kconfig >>> +++ b/fs/nfs/Kconfig >>> @@ -79,15 +79,21 @@ config NFS_V4_1 >>> depends on NFS_FS && NFS_V4 && EXPERIMENTAL >>> select SUNRPC_BACKCHANNEL >>> select PNFS_FILE_LAYOUT >>> + select PNFS_BLOCK >>> + select MD >>> + select BLK_DEV_DM >> >> Why is PNFS_BLOCK enabled automatically in all cases? >> That renders the use of modules for layout drivers totally useless. >> I sort of understand that for PNFS_FILE_LAYOUT (when my >> arm is twisted really hard behind my back :) since it >> is an integral part of RFC5661 but what's the justification >> for PNFS_BLOCK? and why blocks and not objects? > > The question is rather why did objects add a selectable compile option? Just good citizenship :) > What is the point of not compiling a given layout driver if all the > dependencies are met? Reducing build times... Building a smaller kernel when modules are disabled... We're fine in terms of memory consumption when CONFIG_MODULES=y since the layout driver is loaded on demand but shouldn't be worried about the other case? > > IOW: The only thing I'd change above is the select MD and select > BLK_DEV_DM: I'd prefer something like > > config PNFS_BLOCK > depends on NFS_V4_1 && MD && BLK_DEV_DM > default y This is closer to the original version. However, selecting MD and BLK_DEV_DM was proven useful to automatically take care of the module dependencies without having to dive into details. Benny > > Trond > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
