Message ID | 20201019064048.6591-2-chandanrlinux@gmail.com (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Series | Bail out if transaction can cause extent count to overflow | expand |
On 10/18/20 11:40 PM, Chandan Babu R wrote: > XFS does not check for possible overflow of per-inode extent counter > fields when adding extents to either data or attr fork. > > For e.g. > 1. Insert 5 million xattrs (each having a value size of 255 bytes) and > then delete 50% of them in an alternating manner. > > 2. On a 4k block sized XFS filesystem instance, the above causes 98511 > extents to be created in the attr fork of the inode. > > xfsaild/loop0 2008 [003] 1475.127209: probe:xfs_inode_to_disk: (ffffffffa43fb6b0) if_nextents=98511 i_ino=131 > > 3. The incore inode fork extent counter is a signed 32-bit > quantity. However the on-disk extent counter is an unsigned 16-bit > quantity and hence cannot hold 98511 extents. > > 4. The following incorrect value is stored in the attr extent counter, > # xfs_db -f -c 'inode 131' -c 'print core.naextents' /dev/loop0 > core.naextents = -32561 > > This commit adds a new helper function (i.e. > xfs_iext_count_may_overflow()) to check for overflow of the per-inode > data and xattr extent counters. Future patches will use this function to > make sure that an FS operation won't cause the extent counter to > overflow. > Looks good to me Reviewed-by: Allison Henderson <allison.henderson@oracle.com> > Suggested-by: Darrick J. Wong <darrick.wong@oracle.com> > Reviewed-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> > Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com> > --- > fs/xfs/libxfs/xfs_inode_fork.c | 23 +++++++++++++++++++++++ > fs/xfs/libxfs/xfs_inode_fork.h | 2 ++ > 2 files changed, 25 insertions(+) > > diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c > index 7575de5cecb1..8d48716547e5 100644 > --- a/fs/xfs/libxfs/xfs_inode_fork.c > +++ b/fs/xfs/libxfs/xfs_inode_fork.c > @@ -23,6 +23,7 @@ > #include "xfs_da_btree.h" > #include "xfs_dir2_priv.h" > #include "xfs_attr_leaf.h" > +#include "xfs_types.h" > > kmem_zone_t *xfs_ifork_zone; > > @@ -728,3 +729,25 @@ xfs_ifork_verify_local_attr( > > return 0; > } > + > +int > +xfs_iext_count_may_overflow( > + struct xfs_inode *ip, > + int whichfork, > + int nr_to_add) > +{ > + struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); > + uint64_t max_exts; > + uint64_t nr_exts; > + > + if (whichfork == XFS_COW_FORK) > + return 0; > + > + max_exts = (whichfork == XFS_ATTR_FORK) ? MAXAEXTNUM : MAXEXTNUM; > + > + nr_exts = ifp->if_nextents + nr_to_add; > + if (nr_exts < ifp->if_nextents || nr_exts > max_exts) > + return -EFBIG; > + > + return 0; > +} > diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h > index a4953e95c4f3..0beb8e2a00be 100644 > --- a/fs/xfs/libxfs/xfs_inode_fork.h > +++ b/fs/xfs/libxfs/xfs_inode_fork.h > @@ -172,5 +172,7 @@ extern void xfs_ifork_init_cow(struct xfs_inode *ip); > > int xfs_ifork_verify_local_data(struct xfs_inode *ip); > int xfs_ifork_verify_local_attr(struct xfs_inode *ip); > +int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork, > + int nr_to_add); > > #endif /* __XFS_INODE_FORK_H__ */ >
diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c index 7575de5cecb1..8d48716547e5 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.c +++ b/fs/xfs/libxfs/xfs_inode_fork.c @@ -23,6 +23,7 @@ #include "xfs_da_btree.h" #include "xfs_dir2_priv.h" #include "xfs_attr_leaf.h" +#include "xfs_types.h" kmem_zone_t *xfs_ifork_zone; @@ -728,3 +729,25 @@ xfs_ifork_verify_local_attr( return 0; } + +int +xfs_iext_count_may_overflow( + struct xfs_inode *ip, + int whichfork, + int nr_to_add) +{ + struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); + uint64_t max_exts; + uint64_t nr_exts; + + if (whichfork == XFS_COW_FORK) + return 0; + + max_exts = (whichfork == XFS_ATTR_FORK) ? MAXAEXTNUM : MAXEXTNUM; + + nr_exts = ifp->if_nextents + nr_to_add; + if (nr_exts < ifp->if_nextents || nr_exts > max_exts) + return -EFBIG; + + return 0; +} diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h index a4953e95c4f3..0beb8e2a00be 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.h +++ b/fs/xfs/libxfs/xfs_inode_fork.h @@ -172,5 +172,7 @@ extern void xfs_ifork_init_cow(struct xfs_inode *ip); int xfs_ifork_verify_local_data(struct xfs_inode *ip); int xfs_ifork_verify_local_attr(struct xfs_inode *ip); +int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork, + int nr_to_add); #endif /* __XFS_INODE_FORK_H__ */