xfs: widen inode delalloc block counter to 64-bits

Widen the incore inode's i_delayed_blks counter to be a 64-bit integer.
This is necessary to fix an integer overflow problem that can be
reproduced easily now that we use the counter to track blocks that are
assigned to the inode in memory but not on disk.  This includes actual
delalloc reservations as well as real extents in the COW fork that
are waiting to be remapped into the data fork.

These 'delayed mapping' blocks can easily exceed 2^32 blocks if one
creates a very large sparse file of size approximately 2^33 bytes with
one byte written every 2^23 bytes, sets a very large COW extent size
hint of 2^23 blocks, reflinks the first file into a second file, and
then writes a single byte every 2^23 blocks in the original file.

When this happens, we'll try to create approximately 1024 2^23 extent
reservations in the COW fork, which will overflow the counter and cause
problems.

Note that on x64 we end up filling a 4-byte gap in the structure so this
doesn't increase the incore size.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 87e701b..558173f 100644 (file)
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -56,7 +56,7 @@ typedef struct xfs_inode {
        spinlock_t              i_flags_lock;   /* inode i_flags lock */
        /* Miscellaneous state. */
        unsigned long           i_flags;        /* see defined flags below */
-       unsigned int            i_delayed_blks; /* count of delay alloc blks */
+       uint64_t                i_delayed_blks; /* count of delay alloc blks */
 
        struct xfs_icdinode     i_d;            /* most of ondisk inode */
 

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 52ed790..aa6b6db 100644 (file)
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -1812,7 +1812,8 @@ xfs_qm_vop_chown_reserve(
        uint                    flags)
 {
        struct xfs_mount        *mp = ip->i_mount;
-       uint                    delblks, blkflags, prjflags = 0;
+       uint64_t                delblks;
+       unsigned int            blkflags, prjflags = 0;
        struct xfs_dquot        *udq_unres = NULL;
        struct xfs_dquot        *gdq_unres = NULL;
        struct xfs_dquot        *pdq_unres = NULL;