Re: [PATCH 07/12] xfs: remove xfs_iread

Darrick J. Wong
2020-05-16T17:43:23Z

On Fri, May 08, 2020 at 08:34:18AM +0200, Christoph Hellwig wrote:
> There is not much point in the xfs_iread function, as it has a single
> caller and not a whole lot of code. Move it into the only caller,
> and trim down the overdocumentation to just documenting the important
> "why" instead of a lot of redundant "what".
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Brian Foster <bfoster@redhat.com>

Looks reasonable,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
> fs/xfs/libxfs/xfs_inode_buf.c | 73 -----------------------------------
> fs/xfs/libxfs/xfs_inode_buf.h | 2 -
> fs/xfs/xfs_icache.c | 33 +++++++++++++++-
> 3 files changed, 32 insertions(+), 76 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
> index 329534eebbdcc..05f939adea944 100644
> --- a/fs/xfs/libxfs/xfs_inode_buf.c
> +++ b/fs/xfs/libxfs/xfs_inode_buf.c
> @@ -614,79 +614,6 @@ xfs_dinode_calc_crc(
> dip->di_crc = xfs_end_cksum(crc);
> }
>
> -/*
> - * Read the disk inode attributes into the in-core inode structure.
> - *
> - * For version 5 superblocks, if we are initialising a new inode and we are not
> - * utilising the XFS_MOUNT_IKEEP inode cluster mode, we can simple build the new
> - * inode core with a random generation number. If we are keeping inodes around,
> - * we need to read the inode cluster to get the existing generation number off
> - * disk. Further, if we are using version 4 superblocks (i.e. v1/v2 inode
> - * format) then log recovery is dependent on the di_flushiter field being
> - * initialised from the current on-disk value and hence we must also read the
> - * inode off disk.
> - */
> -int
> -xfs_iread(
> - xfs_mount_t *mp,
> - xfs_trans_t *tp,
> - xfs_inode_t *ip,
> - uint iget_flags)
> -{
> - xfs_buf_t *bp;
> - xfs_dinode_t *dip;
> - int error;
> -
> - /*
> - * Fill in the location information in the in-core inode.
> - */
> - error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, iget_flags);
> - if (error)
> - return error;
> -
> - /* shortcut IO on inode allocation if possible */
> - if ((iget_flags & XFS_IGET_CREATE) &&
> - xfs_sb_version_has_v3inode(&mp->m_sb) &&
> - !(mp->m_flags & XFS_MOUNT_IKEEP)) {
> - VFS_I(ip)->i_generation = prandom_u32();
> - return 0;
> - }
> -
> - /*
> - * Get pointers to the on-disk inode and the buffer containing it.
> - */
> - error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &bp, 0);
> - if (error)
> - return error;
> -
> - error = xfs_inode_from_disk(ip, dip);
> - if (error)
> - goto out_brelse;
> -
> - /*
> - * Mark the buffer containing the inode as something to keep
> - * around for a while. This helps to keep recently accessed
> - * meta-data in-core longer.
> - */
> - xfs_buf_set_ref(bp, XFS_INO_REF);
> -
> - /*
> - * Use xfs_trans_brelse() to release the buffer containing the on-disk
> - * inode, because it was acquired with xfs_trans_read_buf() in
> - * xfs_imap_to_bp() above. If tp is NULL, this is just a normal
> - * brelse(). If we're within a transaction, then xfs_trans_brelse()
> - * will only release the buffer if it is not dirty within the
> - * transaction. It will be OK to release the buffer in this case,
> - * because inodes on disk are never destroyed and we will be locking the
> - * new in-core inode before putting it in the cache where other
> - * processes can find it. Thus we don't have to worry about the inode
> - * being changed just because we released the buffer.
> - */
> - out_brelse:
> - xfs_trans_brelse(tp, bp);
> - return error;
> -}
> -
> /*
> * Validate di_extsize hint.
> *
> diff --git a/fs/xfs/libxfs/xfs_inode_buf.h b/fs/xfs/libxfs/xfs_inode_buf.h
> index 0fbb99224ec73..e4cbcaf62a32b 100644
> --- a/fs/xfs/libxfs/xfs_inode_buf.h
> +++ b/fs/xfs/libxfs/xfs_inode_buf.h
> @@ -49,8 +49,6 @@ struct xfs_imap {
> int xfs_imap_to_bp(struct xfs_mount *, struct xfs_trans *,
> struct xfs_imap *, struct xfs_dinode **,
> struct xfs_buf **, uint);
> -int xfs_iread(struct xfs_mount *, struct xfs_trans *,
> - struct xfs_inode *, uint);
> void xfs_dinode_calc_crc(struct xfs_mount *, struct xfs_dinode *);
> void xfs_inode_to_disk(struct xfs_inode *ip, struct xfs_dinode *to,
> xfs_lsn_t lsn);
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index 922a29032e374..af5748f5d9271 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
> @@ -22,6 +22,7 @@
> #include "xfs_dquot_item.h"
> #include "xfs_dquot.h"
> #include "xfs_reflink.h"
> +#include "xfs_ialloc.h"
>
> #include <linux/iversion.h>
>
> @@ -508,10 +509,40 @@ xfs_iget_cache_miss(
> if (!ip)
> return -ENOMEM;
>
> - error = xfs_iread(mp, tp, ip, flags);
> + error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, flags);
> if (error)
> goto out_destroy;
>
> + /*
> + * For version 5 superblocks, if we are initialising a new inode and we
> + * are not utilising the XFS_MOUNT_IKEEP inode cluster mode, we can
> + * simply build the new inode core with a random generation number.
> + *
> + * For version 4 (and older) superblocks, log recovery is dependent on
> + * the di_flushiter field being initialised from the current on-disk
> + * value and hence we must also read the inode off disk even when
> + * initializing new inodes.
> + */
> + if (xfs_sb_version_has_v3inode(&mp->m_sb) &&
> + (flags & XFS_IGET_CREATE) && !(mp->m_flags & XFS_MOUNT_IKEEP)) {
> + VFS_I(ip)->i_generation = prandom_u32();
> + } else {
> + struct xfs_dinode *dip;
> + struct xfs_buf *bp;
> +
> + error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &bp, 0);
> + if (error)
> + goto out_destroy;
> +
> + error = xfs_inode_from_disk(ip, dip);
> + if (!error)
> + xfs_buf_set_ref(bp, XFS_INO_REF);
> + xfs_trans_brelse(tp, bp);
> +
> + if (error)
> + goto out_destroy;
> + }
> +
> if (!xfs_inode_verify_forks(ip)) {
> error = -EFSCORRUPTED;
> goto out_destroy;
> --
> 2.26.2
>