On Tue, Jul 01, 2025 at 12:40:35PM +0200, Christoph Hellwig wrote: > The initial sb read is always for a device logical block size > buffer. The device logical block size is provided in the > bt_logical_sectorsize in struct buftarg, so use that instead of the > confusingly named xfs_getsize_buftarg buffer that reads it from the bdev. > > Update the comments surrounding the code to better describe what is going > on. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> Looks good, Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx> --D > --- > fs/xfs/xfs_buf.h | 1 - > fs/xfs/xfs_mount.c | 21 +++++++++++---------- > 2 files changed, 11 insertions(+), 11 deletions(-) > > diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h > index 15fc56948346..73a9686110e8 100644 > --- a/fs/xfs/xfs_buf.h > +++ b/fs/xfs/xfs_buf.h > @@ -375,7 +375,6 @@ extern void xfs_buftarg_wait(struct xfs_buftarg *); > extern void xfs_buftarg_drain(struct xfs_buftarg *); > int xfs_configure_buftarg(struct xfs_buftarg *btp, unsigned int sectorsize); > > -#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) > #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) > > int xfs_buf_reverify(struct xfs_buf *bp, const struct xfs_buf_ops *ops); > diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c > index 29276fe60df9..047100b080aa 100644 > --- a/fs/xfs/xfs_mount.c > +++ b/fs/xfs/xfs_mount.c > @@ -171,19 +171,16 @@ xfs_readsb( > ASSERT(mp->m_ddev_targp != NULL); > > /* > - * For the initial read, we must guess at the sector > - * size based on the block device. It's enough to > - * get the sb_sectsize out of the superblock and > - * then reread with the proper length. > - * We don't verify it yet, because it may not be complete. > + * In the first pass, use the device sector size to just read enough > + * of the superblock to extract the XFS sector size. > + * > + * The device sector size must be smaller than or equal to the XFS > + * sector size and thus we can always read the superblock. Once we know > + * the XFS sector size, re-read it and run the buffer verifier. > */ > - sector_size = xfs_getsize_buftarg(mp->m_ddev_targp); > + sector_size = mp->m_ddev_targp->bt_logical_sectorsize; > buf_ops = NULL; > > - /* > - * Allocate a (locked) buffer to hold the superblock. This will be kept > - * around at all times to optimize access to the superblock. > - */ > reread: > error = xfs_buf_read_uncached(mp->m_ddev_targp, XFS_SB_DADDR, > BTOBB(sector_size), &bp, buf_ops); > @@ -247,6 +244,10 @@ xfs_readsb( > /* no need to be quiet anymore, so reset the buf ops */ > bp->b_ops = &xfs_sb_buf_ops; > > + /* > + * Keep a pointer of the sb buffer around instead of caching it in the > + * buffer cache because we access it frequently. > + */ > mp->m_sb_bp = bp; > xfs_buf_unlock(bp); > return 0; > -- > 2.47.2 > >
