diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 414903885ab9..72c981e3dc92 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -717,53 +717,30 @@ imap_needs_cow( return true; } +/* + * Extents not yet cached requires exclusive access, don't block for + * IOMAP_NOWAIT. + * + * This is basically an opencoded xfs_ilock_data_map_shared() call, but with + * support for IOMAP_NOWAIT. + */ static int xfs_ilock_for_iomap( struct xfs_inode *ip, unsigned flags, unsigned *lockmode) { - unsigned int mode = *lockmode; - bool is_write = flags & (IOMAP_WRITE | IOMAP_ZERO); - - /* - * 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_cow_inode(ip) && is_write) - mode = XFS_ILOCK_EXCL; - - /* - * Extents not yet cached requires exclusive access, don't block. This - * is an opencoded xfs_ilock_data_map_shared() call but with - * non-blocking behaviour. - */ - if (xfs_need_iread_extents(&ip->i_df)) { - if (flags & IOMAP_NOWAIT) - return -EAGAIN; - mode = XFS_ILOCK_EXCL; - } - -relock: if (flags & IOMAP_NOWAIT) { - if (!xfs_ilock_nowait(ip, mode)) + if (xfs_need_iread_extents(&ip->i_df)) + return -EAGAIN; + if (!xfs_ilock_nowait(ip, *lockmode)) return -EAGAIN; } else { - xfs_ilock(ip, mode); + if (xfs_need_iread_extents(&ip->i_df)) + *lockmode = XFS_ILOCK_EXCL; + xfs_ilock(ip, *lockmode); } - /* - * The reflink iflag could have changed since the earlier unlocked - * check, so if we got ILOCK_SHARED for a write and but we're now a - * reflink inode we have to switch to ILOCK_EXCL and relock. - */ - if (mode == XFS_ILOCK_SHARED && is_write && xfs_is_cow_inode(ip)) { - xfs_iunlock(ip, mode); - mode = XFS_ILOCK_EXCL; - goto relock; - } - - *lockmode = mode; return 0; } @@ -801,7 +778,7 @@ xfs_direct_write_iomap_begin( int nimaps = 1, error = 0; bool shared = false; u16 iomap_flags = 0; - unsigned int lockmode = XFS_ILOCK_SHARED; + unsigned int lockmode; u64 seq; ASSERT(flags & (IOMAP_WRITE | IOMAP_ZERO)); @@ -817,10 +794,30 @@ xfs_direct_write_iomap_begin( if (offset + length > i_size_read(inode)) iomap_flags |= IOMAP_F_DIRTY; + /* + * 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_cow_inode(ip)) + lockmode = XFS_ILOCK_EXCL; + else + lockmode = XFS_ILOCK_SHARED; + +relock: error = xfs_ilock_for_iomap(ip, flags, &lockmode); if (error) return error; + /* + * The reflink iflag could have changed since the earlier unlocked + * check, check if it again and relock if needed. + */ + if (xfs_is_cow_inode(ip) && lockmode == XFS_ILOCK_SHARED) { + xfs_iunlock(ip, lockmode); + lockmode = XFS_ILOCK_EXCL; + goto relock; + } + error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, &nimaps, 0); if (error)