xfs: apply rt extent alignment constraints to CoW extsize hint

The copy-on-write extent size hint is subject to the same alignment
constraints as the regular extent size hint.  Since we're in the process
of adding reflink (and therefore CoW) to the realtime device, we must
apply the same scattered rextsize alignment validation strategies to
both hints to deal with the possibility of rextsize changing.

Therefore, fix the inode validator to perform rextsize alignment checks
on regular realtime files, and to remove misaligned directory hints.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/libxfs/logitem.c b/libxfs/logitem.c
index 7757259dfc5e424bb0c5ce7cc3b25b51141790ee..062d6311b942ae43971fb341315d81458e114d54 100644 (file)
--- a/libxfs/logitem.c
+++ b/libxfs/logitem.c
@@ -233,6 +233,20 @@ xfs_inode_item_precommit(
        if (flags & XFS_ILOG_IVERSION)
                flags = ((flags & ~XFS_ILOG_IVERSION) | XFS_ILOG_CORE);
 
+       /*
+        * Inode verifiers do not check that the CoW extent size hint is an
+        * integer multiple of the rt extent size on a directory with both
+        * rtinherit and cowextsize flags set.  If we're logging a directory
+        * that is misconfigured in this way, clear the hint.
+        */
+       if ((ip->i_diflags & XFS_DIFLAG_RTINHERIT) &&
+           (ip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) &&
+           xfs_extlen_to_rtxmod(ip->i_mount, ip->i_cowextsize) > 0) {
+               ip->i_diflags2 &= ~XFS_DIFLAG2_COWEXTSIZE;
+               ip->i_cowextsize = 0;
+               flags |= XFS_ILOG_CORE;
+       }
+
        if (!iip->ili_item.li_buf) {
                struct xfs_buf  *bp;
                int             error;

diff --git a/libxfs/xfs_inode_buf.c b/libxfs/xfs_inode_buf.c
index 196562f574cd031d12bea5f43f44b6789baa138f..d6451318dca539bc5cc9dad3dd14006e48089e5c 100644 (file)
--- a/libxfs/xfs_inode_buf.c
+++ b/libxfs/xfs_inode_buf.c
@@ -899,11 +899,29 @@ xfs_inode_validate_cowextsize(
        bool                            rt_flag;
        bool                            hint_flag;
        uint32_t                        cowextsize_bytes;
+       uint32_t                        blocksize_bytes;
 
        rt_flag = (flags & XFS_DIFLAG_REALTIME);
        hint_flag = (flags2 & XFS_DIFLAG2_COWEXTSIZE);
        cowextsize_bytes = XFS_FSB_TO_B(mp, cowextsize);
 
+       /*
+        * Similar to extent size hints, a directory can be configured to
+        * propagate realtime status and a CoW extent size hint to newly
+        * created files even if there is no realtime device, and the hints on
+        * disk can become misaligned if the sysadmin changes the rt extent
+        * size while adding the realtime device.
+        *
+        * Therefore, we can only enforce the rextsize alignment check against
+        * regular realtime files, and rely on callers to decide when alignment
+        * checks are appropriate, and fix things up as needed.
+        */
+
+       if (rt_flag)
+               blocksize_bytes = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize);
+       else
+               blocksize_bytes = mp->m_sb.sb_blocksize;
+
        if (hint_flag && !xfs_has_reflink(mp))
                return __this_address;
 
@@ -917,16 +935,13 @@ xfs_inode_validate_cowextsize(
        if (mode && !hint_flag && cowextsize != 0)
                return __this_address;
 
-       if (hint_flag && rt_flag)
-               return __this_address;
-
-       if (cowextsize_bytes % mp->m_sb.sb_blocksize)
+       if (cowextsize_bytes % blocksize_bytes)
                return __this_address;
 
        if (cowextsize > XFS_MAX_BMBT_EXTLEN)
                return __this_address;
 
-       if (cowextsize > mp->m_sb.sb_agblocks / 2)
+       if (!rt_flag && cowextsize > mp->m_sb.sb_agblocks / 2)
                return __this_address;
 
        return NULL;