On Tue, Jun 08, 2021 at 04:59:48PM +0200, Carlos Maiolino wrote: > Hi, > > On Sun, Jun 06, 2021 at 10:54:17AM -0700, Darrick J. Wong wrote: > > From: Darrick J. Wong <djwong@xxxxxxxxxx> > > > > When we decide to mark an inode sick, clear the DONTCACHE flag so that > > the incore inode will be kept around until memory pressure forces it out > > of memory. This increases the chances that the sick status will be > > caught by someone compiling a health report later on. > > > > Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> > > The patch looks ok, so you can add: > > Reviewed-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx> > > > Now, I have a probably dumb question about this. > > by removing the I_DONTCACHE flag, as you said, we are increasing the chances > that the sick status will be caught, so, in either case, it seems not reliable. > So, my dumb question is, is there reason having these inodes around will benefit > us somehow? I haven't read the whole code, but I assume, it can be used as a > fast path while scrubbing the FS? Two answers to your question: In the short term, preserving the incore inode means that a subsequent reporting run (xfs_spaceman -c 'health') is more likely to pick up the sickness report. In the longer term, I intend to re-enable reclamation of sick inodes by aggregating the per-inode sick bit in the per-AG health status so that reporting won't be interrupted by memory demand: [1] https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=indirect-health-reporting (I haven't rebased that part in quite a while though.) --D > > Cheers. > > > --- > > fs/xfs/xfs_health.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > > > diff --git a/fs/xfs/xfs_health.c b/fs/xfs/xfs_health.c > > index 8e0cb05a7142..806be8a93ea3 100644 > > --- a/fs/xfs/xfs_health.c > > +++ b/fs/xfs/xfs_health.c > > @@ -231,6 +231,15 @@ xfs_inode_mark_sick( > > ip->i_sick |= mask; > > ip->i_checked |= mask; > > spin_unlock(&ip->i_flags_lock); > > + > > + /* > > + * Keep this inode around so we don't lose the sickness report. Scrub > > + * grabs inodes with DONTCACHE assuming that most inode are ok, which > > + * is not the case here. > > + */ > > + spin_lock(&VFS_I(ip)->i_lock); > > + VFS_I(ip)->i_state &= ~I_DONTCACHE; > > + spin_unlock(&VFS_I(ip)->i_lock); > > } > > > > /* Mark parts of an inode healed. */ > > > > -- > Carlos >
