On Mon, Feb 24, 2014 at 05:10:31PM -0600, Eric Sandeen wrote: > Because we have lazy counters, it's possible that we over-allocate > inodes past the maxicount (imaxpct) limit. > > A previous commit, > > 2fe3366 xfs: ensure f_ffree returned by statfs() is non-negative > > stopped statfs from underflowing f_ffree in this case, but that > only happened when we mis-reported f_files, capped at maxicount. > > Change statfs to report the actual number of inodes allocated, > even if it is greater than maxicount. It's reality. > Deal with it. > > (New clearer code flow thanks to Brian!) > > Logic-made-readable-by: Brian Foster <bfoster@xxxxxxxxxx> > Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> > --- > > V2: Use Brian's suggested logic for working out the numbers > > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c > index f317488..0dbcc17 100644 > --- a/fs/xfs/xfs_super.c > +++ b/fs/xfs/xfs_super.c > @@ -1083,7 +1083,6 @@ xfs_fs_statfs( > struct xfs_inode *ip = XFS_I(dentry->d_inode); > __uint64_t fakeinos, id; > xfs_extlen_t lsize; > - __int64_t ffree; > > statp->f_type = XFS_SB_MAGIC; > statp->f_namelen = MAXNAMELEN - 1; > @@ -1100,17 +1099,19 @@ xfs_fs_statfs( > statp->f_blocks = sbp->sb_dblocks - lsize; > statp->f_bfree = statp->f_bavail = > sbp->sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp); > + /* > + * Potential number of new inodes in free blocks, limited by maxicount. > + */ > fakeinos = statp->f_bfree << sbp->sb_inopblog; Can we rename "fakeinos" to something like "free_inodes" so that the code reads a little bit better while we are touching this code? > - statp->f_files = > - MIN(sbp->sb_icount + fakeinos, (__uint64_t)XFS_MAXINUMBER); > if (mp->m_maxicount) > - statp->f_files = min_t(typeof(statp->f_files), > - statp->f_files, > - mp->m_maxicount); > + fakeinos = mp->m_maxicount > sbp->sb_icount ? > + MIN(mp->m_maxicount - sbp->sb_icount, fakeinos) : 0; Get rid of MIN - it should be min() or min_t(). Also the mix of if() and ternary operations makes this difficult to follow the logic. Better, IMO, is this: free_inodes = statp->f_bfree << sbp->sb_inopblog; if (mp->m_maxicount > sbp->sb_icount) free_inodes = min(mp->m_maxicount - sbp->sb_icount, free_inodes); else if (mp->m_maxicount) free_inodes = 0; > + > + /* Total possible files is current inodes + potential new inodes */ > + statp->f_files = MIN(sbp->sb_icount + fakeinos, > + (__uint64_t) XFS_MAXINUMBER); statp->f_files = min_t(u64, sbp->sb_icount + free_inodes, XFS_MAXINUMBER); And for bonus points: while we are looking at maxicount, the setting on maxicount in the growfs code should call xfs_set_maxicount() rather than open coding it, and xfs_set_maxicount() needs to be reworked to prevent overflow when sbp->sb_dblocks * sbp->sb_imax_pct is greater than 64 bits.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
