From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liu Bo Subject: Re: [PATCH] Btrfs: do not mount when we have a sectorsize unequal to PAGE_SIZE Date: Tue, 03 Apr 2012 16:35:28 +0800 Message-ID: <4F7AB650.3000108@cn.fujitsu.com> References: <1333418213-2718-1-git-send-email-liubo2009@cn.fujitsu.com> <20120403080659.GF1084@x2.net.home> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-btrfs@vger.kernel.org To: Karel Zak Return-path: In-Reply-To: <20120403080659.GF1084@x2.net.home> List-ID: On 04/03/2012 04:06 PM, Karel Zak wrote: > On Tue, Apr 03, 2012 at 09:56:53AM +0800, Liu Bo wrote: >> Our code is not ready to cope with a sectorsize that's not equal to PAGE_SIZE. >> It will lead to hanging-on while writing something. >> >> Signed-off-by: Liu Bo >> --- >> fs/btrfs/disk-io.c | 6 +++--- >> 1 files changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c >> index 20196f4..b9866f2 100644 >> --- a/fs/btrfs/disk-io.c >> +++ b/fs/btrfs/disk-io.c >> @@ -2254,9 +2254,9 @@ int open_ctree(struct super_block *sb, >> goto fail_sb_buffer; >> } >> >> - if (sectorsize < PAGE_SIZE) { >> - printk(KERN_WARNING "btrfs: Incompatible sector size " >> - "found on %s\n", sb->s_id); >> + if (sectorsize != PAGE_SIZE) { >> + printk(KERN_WARNING "btrfs: Incompatible sector size(%lu) " >> + "found on %s\n", (unsigned long)sectorsize, sb->s_id); > > That's strange. Does it mean that if I create the filesystem and then > reboot to another kernel with different PAGE_SIZE then the filesystem > is unaccessible for me? > > Karel > I'm afraid yes until we can deal with sectorsize and PAGE_SIZE gracefully. For now, I didn't test if a read will cause oops or not, but if it's ok, an alternative way is to make FS readonly. thanks, liubo