From 00dd8d7ec5253c6273023a0fd6dc08683e0bdfef Mon Sep 17 00:00:00 2001 From: Yuto Ohnuki Date: Sat, 11 Apr 2026 15:24:13 +0100 Subject: [PATCH] xfs: zero entire directory data block header region at init xfs_dir3_data_init currently zeroes only the xfs_dir3_blk_hdr portion of the directory data block header, then manually initializes the bestfree entries in a loop. This leaves the pad field in xfs_dir3_data_hdr uninitialized and requires explicit zeroing of each bestfree slot. Zero the entire header region (geo->data_entry_offset bytes) unconditionally before setting individual fields. This covers all current and future header fields, all padding (implicit and explicit), and the bestfree array, so the manual zeroing loop for bestfree can be removed. Suggested-by: Dave Chinner Signed-off-by: Yuto Ohnuki Reviewed-by: Darrick J. Wong Signed-off-by: Carlos Maiolino --- fs/xfs/libxfs/xfs_dir2_data.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/fs/xfs/libxfs/xfs_dir2_data.c b/fs/xfs/libxfs/xfs_dir2_data.c index 80ba94f51e5c..35ff119aa84b 100644 --- a/fs/xfs/libxfs/xfs_dir2_data.c +++ b/fs/xfs/libxfs/xfs_dir2_data.c @@ -728,7 +728,6 @@ xfs_dir3_data_init( struct xfs_dir2_data_unused *dup; struct xfs_dir2_data_free *bf; int error; - int i; /* * Get the buffer set up for the block. @@ -741,13 +740,16 @@ xfs_dir3_data_init( xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_DATA_BUF); /* - * Initialize the header. + * Initialize the whole directory header region to zero + * so that all padding, bestfree entries, and any + * future header fields are clean. */ hdr = bp->b_addr; + memset(hdr, 0, geo->data_entry_offset); + if (xfs_has_crc(mp)) { struct xfs_dir3_blk_hdr *hdr3 = bp->b_addr; - memset(hdr3, 0, sizeof(*hdr3)); hdr3->magic = cpu_to_be32(XFS_DIR3_DATA_MAGIC); hdr3->blkno = cpu_to_be64(xfs_buf_daddr(bp)); hdr3->owner = cpu_to_be64(args->owner); @@ -759,10 +761,6 @@ xfs_dir3_data_init( bf = xfs_dir2_data_bestfree_p(mp, hdr); bf[0].offset = cpu_to_be16(geo->data_entry_offset); bf[0].length = cpu_to_be16(geo->blksize - geo->data_entry_offset); - for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) { - bf[i].length = 0; - bf[i].offset = 0; - } /* * Set up an unused entry for the block's body.