From: Dan Williams Subject: Re: [PATCH 4/5] dax: use sb_issue_zerout instead of calling dax_clear_sectors Date: Fri, 25 Mar 2016 14:20:39 -0700 Message-ID: References: <1458861450-17705-1-git-send-email-vishal.l.verma@intel.com> <1458861450-17705-5-git-send-email-vishal.l.verma@intel.com> <1458939796.5501.8.camel@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: "linux-block@vger.kernel.org" , "xfs@oss.sgi.com" , "linux-mm@kvack.org" , "viro@zeniv.linux.org.uk" , "axboe@fb.com" , "akpm@linux-foundation.org" , "linux-nvdimm@lists.01.org" , "linux-fsdevel@vger.kernel.org" , "ross.zwisler@linux.intel.com" , "linux-ext4@vger.kernel.org" , "Wilcox, Matthew R" , "david@fromorbit.com" , "jack@suse.cz" To: "Verma, Vishal L" Return-path: In-Reply-To: <1458939796.5501.8.camel@intel.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org On Fri, Mar 25, 2016 at 2:03 PM, Verma, Vishal L wrote: > On Fri, 2016-03-25 at 11:47 -0700, Dan Williams wrote: >> On Thu, Mar 24, 2016 at 4:17 PM, Vishal Verma > om> wrote: >> > >> > From: Matthew Wilcox >> > >> > dax_clear_sectors() cannot handle poisoned blocks. These must be >> > zeroed using the BIO interface instead. Convert ext2 and XFS to >> > use >> > only sb_issue_zerout(). >> > >> > Signed-off-by: Matthew Wilcox >> > [vishal: Also remove the dax_clear_sectors function entirely] >> > Signed-off-by: Vishal Verma >> > --- >> > fs/dax.c | 32 -------------------------------- >> > fs/ext2/inode.c | 7 +++---- >> > fs/xfs/xfs_bmap_util.c | 9 --------- >> > include/linux/dax.h | 1 - >> > 4 files changed, 3 insertions(+), 46 deletions(-) >> > >> > diff --git a/fs/dax.c b/fs/dax.c >> > index bb7e9f8..a30481e 100644 >> > --- a/fs/dax.c >> > +++ b/fs/dax.c >> > @@ -78,38 +78,6 @@ struct page *read_dax_sector(struct block_device >> > *bdev, sector_t n) >> > return page; >> > } >> > >> > -/* >> > - * dax_clear_sectors() is called from within transaction context >> > from XFS, >> > - * and hence this means the stack from this point must follow >> > GFP_NOFS >> > - * semantics for all operations. >> > - */ >> > -int dax_clear_sectors(struct block_device *bdev, sector_t _sector, >> > long _size) >> > -{ >> > - struct blk_dax_ctl dax = { >> > - .sector = _sector, >> > - .size = _size, >> > - }; >> > - >> > - might_sleep(); >> > - do { >> > - long count, sz; >> > - >> > - count = dax_map_atomic(bdev, &dax); >> > - if (count < 0) >> > - return count; >> > - sz = min_t(long, count, SZ_128K); >> > - clear_pmem(dax.addr, sz); >> > - dax.size -= sz; >> > - dax.sector += sz / 512; >> > - dax_unmap_atomic(bdev, &dax); >> > - cond_resched(); >> > - } while (dax.size); >> > - >> > - wmb_pmem(); >> > - return 0; >> > -} >> > -EXPORT_SYMBOL_GPL(dax_clear_sectors); >> What about the other unwritten extent conversions in the dax path? >> Shouldn't those be converted to block-layer zero-outs as well? > > Could you point me to where these might be? I thought once we've > converted all the zeroout type callers (by removing dax_clear_sectors), > and fixed up dax_do_io to try a driver fallback, we've handled all the > media error cases in dax.. grep for usages of clear_pmem()... which I was hoping to eliminate after this change to push zeroing down to the driver. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org