(IS_DAX(inode) && imap->br_state == XFS_EXT_UNWRITTEN);
}
+static inline bool needs_cow_for_zeroing(struct xfs_bmbt_irec *imap, int nimaps)
+{
+ return nimaps &&
+ imap->br_startblock != HOLESTARTBLOCK &&
+ imap->br_state != XFS_EXT_UNWRITTEN;
+}
+
static inline bool need_excl_ilock(struct xfs_inode *ip, unsigned flags)
{
/*
- * COW writes will allocate delalloc space, so we need to make sure
- * to take the lock exclusively here.
+ * COW writes may allocate delalloc space or convert unwritten COW
+ * extents, so we need to make sure to take the lock exclusively here.
*/
if (xfs_is_reflink_inode(ip) && (flags & (IOMAP_WRITE | IOMAP_ZERO)))
return true;
- if ((flags & IOMAP_DIRECT) && (flags & IOMAP_WRITE))
+
+ /*
+ * Extents not yet cached requires exclusive access, don't block.
+ * This is an opencoded xfs_ilock_data_map_shared() to cater for the
+ * non-blocking behaviour.
+ */
+ if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
+ !(ip->i_df.if_flags & XFS_IFEXTENTS))
return true;
return false;
}
return xfs_file_iomap_begin_delay(inode, offset, length, iomap);
}
- if (need_excl_ilock(ip, flags)) {
+ if (need_excl_ilock(ip, flags))
lockmode = XFS_ILOCK_EXCL;
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- } else {
- lockmode = xfs_ilock_data_map_shared(ip);
- }
+ else
+ lockmode = XFS_ILOCK_SHARED;
- if ((flags & IOMAP_NOWAIT) && !(ip->i_df.if_flags & XFS_IFEXTENTS)) {
- error = -EAGAIN;
- goto out_unlock;
+ if (flags & IOMAP_NOWAIT) {
+ if (!(ip->i_df.if_flags & XFS_IFEXTENTS))
+ return -EAGAIN;
+ if (!xfs_ilock_nowait(ip, lockmode))
+ return -EAGAIN;
+ } else {
+ xfs_ilock(ip, lockmode);
}
ASSERT(offset <= mp->m_super->s_maxbytes);
- if ((xfs_fsize_t)offset + length > mp->m_super->s_maxbytes)
+ if (offset > mp->m_super->s_maxbytes - length)
length = mp->m_super->s_maxbytes - offset;
offset_fsb = XFS_B_TO_FSBT(mp, offset);
end_fsb = XFS_B_TO_FSB(mp, offset + length);
goto out_unlock;
}
- if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && xfs_is_reflink_inode(ip)) {
+ if (xfs_is_reflink_inode(ip) &&
+ ((flags & IOMAP_WRITE) ||
+ ((flags & IOMAP_ZERO) && needs_cow_for_zeroing(&imap, nimaps)))) {
if (flags & IOMAP_DIRECT) {
/*
* A reflinked inode will result in CoW alloc.