| Message ID | 1f6a98905845d1b03cf0aa96539715d29da32034.1545438588.git.osandov@fb.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | xfs: reallocate realtime summary cache on growfs | expand |
On Fri, Dec 21, 2018 at 04:32:38PM -0800, Omar Sandoval wrote: > From: Omar Sandoval <osandov@fb.com> > > At mount time, we allocate m_rsum_cache with the number of realtime > bitmap blocks. However, xfs_growfs_rt() can increase the number of > realtime bitmap blocks. Using the cache after this happens may access > out of the bounds of the cache. Fix it by reallocating the cache in this > case. > > Fixes: 355e3532132b ("xfs: cache minimum realtime summary level") > Signed-off-by: Omar Sandoval <osandov@fb.com> Looks ok (though rt growfs seems to have unrelated lurking bugs...), Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > --- > Hi, > > This is a quick for for my previous patch which is queued up for 4.21, > based on xfs-linux/for-next. This is bad timing with the holidays coming > up, but growfs on a realtime volume is probably pretty rare :) > > Thanks! > > fs/xfs/xfs_rtalloc.c | 44 ++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 36 insertions(+), 8 deletions(-) > > diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c > index afe4d29f7ab4..ac0fcdad0c4e 100644 > --- a/fs/xfs/xfs_rtalloc.c > +++ b/fs/xfs/xfs_rtalloc.c > @@ -861,6 +861,21 @@ xfs_growfs_rt_alloc( > return error; > } > > +static void > +xfs_alloc_rsum_cache( > + xfs_mount_t *mp, /* file system mount structure */ > + xfs_extlen_t rbmblocks) /* number of rt bitmap blocks */ > +{ > + /* > + * The rsum cache is initialized to all zeroes, which is trivially a > + * lower bound on the minimum level with any free extents. We can > + * continue without the cache if it couldn't be allocated. > + */ > + mp->m_rsum_cache = kmem_zalloc_large(rbmblocks, KM_SLEEP); > + if (!mp->m_rsum_cache) > + xfs_warn(mp, "could not allocate realtime summary cache"); > +} > + > /* > * Visible (exported) functions. > */ > @@ -889,6 +904,7 @@ xfs_growfs_rt( > xfs_extlen_t rsumblocks; /* current number of rt summary blks */ > xfs_sb_t *sbp; /* old superblock */ > xfs_fsblock_t sumbno; /* summary block number */ > + uint8_t *rsum_cache; /* old summary cache */ > > sbp = &mp->m_sb; > /* > @@ -945,6 +961,11 @@ xfs_growfs_rt( > error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip); > if (error) > return error; > + > + rsum_cache = mp->m_rsum_cache; > + if (nrbmblocks != sbp->sb_rbmblocks) > + xfs_alloc_rsum_cache(mp, nrbmblocks); > + > /* > * Allocate a new (fake) mount/sb. > */ > @@ -1070,6 +1091,20 @@ xfs_growfs_rt( > */ > kmem_free(nmp); > > + /* > + * If we had to allocate a new rsum_cache, we either need to free the > + * old one (if we succeeded) or free the new one and restore the old one > + * (if there was an error). > + */ > + if (rsum_cache != mp->m_rsum_cache) { > + if (error) { > + kmem_free(mp->m_rsum_cache); > + mp->m_rsum_cache = rsum_cache; > + } else { > + kmem_free(rsum_cache); > + } > + } > + > return error; > } > > @@ -1217,14 +1252,7 @@ xfs_rtmount_inodes( > return error; > } > ASSERT(mp->m_rsumip != NULL); > - /* > - * The rsum cache is initialized to all zeroes, which is trivially a > - * lower bound on the minimum level with any free extents. We can > - * continue without the cache if it couldn't be allocated. > - */ > - mp->m_rsum_cache = kmem_zalloc_large(sbp->sb_rbmblocks, KM_SLEEP); > - if (!mp->m_rsum_cache) > - xfs_warn(mp, "could not allocate realtime summary cache"); > + xfs_alloc_rsum_cache(mp, sbp->sb_rbmblocks); > return 0; > } > > -- > 2.20.1 >
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c index afe4d29f7ab4..ac0fcdad0c4e 100644 --- a/fs/xfs/xfs_rtalloc.c +++ b/fs/xfs/xfs_rtalloc.c @@ -861,6 +861,21 @@ xfs_growfs_rt_alloc( return error; } +static void +xfs_alloc_rsum_cache( + xfs_mount_t *mp, /* file system mount structure */ + xfs_extlen_t rbmblocks) /* number of rt bitmap blocks */ +{ + /* + * The rsum cache is initialized to all zeroes, which is trivially a + * lower bound on the minimum level with any free extents. We can + * continue without the cache if it couldn't be allocated. + */ + mp->m_rsum_cache = kmem_zalloc_large(rbmblocks, KM_SLEEP); + if (!mp->m_rsum_cache) + xfs_warn(mp, "could not allocate realtime summary cache"); +} + /* * Visible (exported) functions. */ @@ -889,6 +904,7 @@ xfs_growfs_rt( xfs_extlen_t rsumblocks; /* current number of rt summary blks */ xfs_sb_t *sbp; /* old superblock */ xfs_fsblock_t sumbno; /* summary block number */ + uint8_t *rsum_cache; /* old summary cache */ sbp = &mp->m_sb; /* @@ -945,6 +961,11 @@ xfs_growfs_rt( error = xfs_growfs_rt_alloc(mp, rsumblocks, nrsumblocks, mp->m_rsumip); if (error) return error; + + rsum_cache = mp->m_rsum_cache; + if (nrbmblocks != sbp->sb_rbmblocks) + xfs_alloc_rsum_cache(mp, nrbmblocks); + /* * Allocate a new (fake) mount/sb. */ @@ -1070,6 +1091,20 @@ xfs_growfs_rt( */ kmem_free(nmp); + /* + * If we had to allocate a new rsum_cache, we either need to free the + * old one (if we succeeded) or free the new one and restore the old one + * (if there was an error). + */ + if (rsum_cache != mp->m_rsum_cache) { + if (error) { + kmem_free(mp->m_rsum_cache); + mp->m_rsum_cache = rsum_cache; + } else { + kmem_free(rsum_cache); + } + } + return error; } @@ -1217,14 +1252,7 @@ xfs_rtmount_inodes( return error; } ASSERT(mp->m_rsumip != NULL); - /* - * The rsum cache is initialized to all zeroes, which is trivially a - * lower bound on the minimum level with any free extents. We can - * continue without the cache if it couldn't be allocated. - */ - mp->m_rsum_cache = kmem_zalloc_large(sbp->sb_rbmblocks, KM_SLEEP); - if (!mp->m_rsum_cache) - xfs_warn(mp, "could not allocate realtime summary cache"); + xfs_alloc_rsum_cache(mp, sbp->sb_rbmblocks); return 0; }