Re: [PATCH 19/22] xfs: get rid of xfs_dir_ialloc()

Darrick J. Wong
2021-05-12T23:44:18Z

On Thu, May 06, 2021 at 05:20:51PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> This is just a simple wrapper around the per-ag inode allocation
> that doesn't need to exist. The internal mechanism to select and
> allocate within an AG does not need to be exposed outside
> xfs_ialloc.c, and it being exposed simply makes it harder to follow
> the code and simplify it.
>
> This is simplified by internalising xf_dialloc_select_ag() and
> xfs_dialloc_ag() into a single xfs_dialloc() function and then
> xfs_dir_ialloc() can go away.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

Aha, I see what you did here with disappearing xfs_dialloc_select_ag.
Ignore my later comments about 5.11 and whatnot.

This'll cause some churn in the metadata directory tree patchset, but
it's not like that hasn't happened 5x before. :P

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> fs/xfs/libxfs/xfs_ialloc.c | 15 +++++----
> fs/xfs/libxfs/xfs_ialloc.h | 27 +++-------------
> fs/xfs/xfs_inode.c | 66 +++++++-------------------------------
> fs/xfs/xfs_inode.h | 9 +++---
> fs/xfs/xfs_qm.c | 9 ++++--
> fs/xfs/xfs_symlink.c | 9 ++++--
> 6 files changed, 43 insertions(+), 92 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
> index b22556556bba..2c0ef2dd46d9 100644
> --- a/fs/xfs/libxfs/xfs_ialloc.c
> +++ b/fs/xfs/libxfs/xfs_ialloc.c
> @@ -1602,24 +1602,23 @@ xfs_ialloc_next_ag(
> * can be allocated, -ENOSPC be returned.
> */
> int
> -xfs_dialloc_select_ag(
> +xfs_dialloc(
> struct xfs_trans **tpp,
> xfs_ino_t parent,
> umode_t mode,
> - struct xfs_buf **IO_agbp)
> + xfs_ino_t *new_ino)
> {
> struct xfs_mount *mp = (*tpp)->t_mountp;
> struct xfs_buf *agbp;
> xfs_agnumber_t agno;
> - int error;
> + int error = 0;
> xfs_agnumber_t start_agno;
> struct xfs_perag *pag;
> struct xfs_ino_geometry *igeo = M_IGEO(mp);
> bool okalloc = true;
> int needspace;
> int flags;
> -
> - *IO_agbp = NULL;
> + xfs_ino_t ino;
>
> /*
> * Files of these types need at least one block if length > 0
> @@ -1763,7 +1762,11 @@ xfs_dialloc_select_ag(
> return error ? error : -ENOSPC;
> found_ag:
> xfs_perag_put(pag);
> - *IO_agbp = agbp;
> + /* Allocate an inode in the found AG */
> + error = xfs_dialloc_ag(*tpp, agbp, parent, &ino);
> + if (error)
> + return error;
> + *new_ino = ino;
> return 0;
> }
>
> diff --git a/fs/xfs/libxfs/xfs_ialloc.h b/fs/xfs/libxfs/xfs_ialloc.h
> index 3511086a7ae1..886f6748fb22 100644
> --- a/fs/xfs/libxfs/xfs_ialloc.h
> +++ b/fs/xfs/libxfs/xfs_ialloc.h
> @@ -33,30 +33,11 @@ xfs_make_iptr(struct xfs_mount *mp, struct xfs_buf *b, int o)
> }
>
> /*
> - * Allocate an inode on disk.
> - * Mode is used to tell whether the new inode will need space, and whether
> - * it is a directory.
> - *
> - * There are two phases to inode allocation: selecting an AG and ensuring
> - * that it contains free inodes, followed by allocating one of the free
> - * inodes. xfs_dialloc_select_ag() does the former and returns a locked AGI
> - * to the caller, ensuring that followup call to xfs_dialloc_ag() will
> - * have free inodes to allocate from. xfs_dialloc_ag() will return the inode
> - * number of the free inode we allocated.
> + * Allocate an inode on disk. Mode is used to tell whether the new inode will
> + * need space, and whether it is a directory.
> */
> -int /* error */
> -xfs_dialloc_select_ag(
> - struct xfs_trans **tpp, /* double pointer of transaction */
> - xfs_ino_t parent, /* parent inode (directory) */
> - umode_t mode, /* mode bits for new inode */
> - struct xfs_buf **IO_agbp);
> -
> -int
> -xfs_dialloc_ag(
> - struct xfs_trans *tp,
> - struct xfs_buf *agbp,
> - xfs_ino_t parent,
> - xfs_ino_t *inop);
> +int xfs_dialloc(struct xfs_trans **tpp, xfs_ino_t parent, umode_t mode,
> + xfs_ino_t *new_ino);
>
> /*
> * Free disk inode. Carefully avoids touching the incore inode, all
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 3918c99fa95b..26668b6846e2 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -749,7 +749,7 @@ xfs_inode_inherit_flags2(
> * Initialise a newly allocated inode and return the in-core inode to the
> * caller locked exclusively.
> */
> -static int
> +int
> xfs_init_new_inode(
> struct user_namespace *mnt_userns,
> struct xfs_trans *tp,
> @@ -885,54 +885,6 @@ xfs_init_new_inode(
> return 0;
> }
>
> -/*
> - * Allocates a new inode from disk and return a pointer to the incore copy. This
> - * routine will internally commit the current transaction and allocate a new one
> - * if we needed to allocate more on-disk free inodes to perform the requested
> - * operation.
> - *
> - * If we are allocating quota inodes, we do not have a parent inode to attach to
> - * or associate with (i.e. dp == NULL) because they are not linked into the
> - * directory structure - they are attached directly to the superblock - and so
> - * have no parent.
> - */
> -int
> -xfs_dir_ialloc(
> - struct user_namespace *mnt_userns,
> - struct xfs_trans **tpp,
> - struct xfs_inode *dp,
> - umode_t mode,
> - xfs_nlink_t nlink,
> - dev_t rdev,
> - prid_t prid,
> - bool init_xattrs,
> - struct xfs_inode **ipp)
> -{
> - struct xfs_buf *agibp;
> - xfs_ino_t parent_ino = dp ? dp->i_ino : 0;
> - xfs_ino_t ino;
> - int error;
> -
> - ASSERT((*tpp)->t_flags & XFS_TRANS_PERM_LOG_RES);
> -
> - /*
> - * Call the space management code to pick the on-disk inode to be
> - * allocated.
> - */
> - error = xfs_dialloc_select_ag(tpp, parent_ino, mode, &agibp);
> - if (error)
> - return error;
> -
> - /* Allocate an inode from the selected AG */
> - error = xfs_dialloc_ag(*tpp, agibp, parent_ino, &ino);
> - if (error)
> - return error;
> - ASSERT(ino != NULLFSINO);
> -
> - return xfs_init_new_inode(mnt_userns, *tpp, dp, ino, mode, nlink, rdev,
> - prid, init_xattrs, ipp);
> -}
> -
> /*
> * Decrement the link count on an inode & log the change. If this causes the
> * link count to go to zero, move the inode to AGI unlinked list so that it can
> @@ -990,6 +942,7 @@ xfs_create(
> struct xfs_dquot *pdqp = NULL;
> struct xfs_trans_res *tres;
> uint resblks;
> + xfs_ino_t ino;
>
> trace_xfs_create(dp, name);
>
> @@ -1046,14 +999,16 @@ xfs_create(
> * entry pointing to them, but a directory also the "." entry
> * pointing to itself.
> */
> - error = xfs_dir_ialloc(mnt_userns, &tp, dp, mode, is_dir ? 2 : 1, rdev,
> - prid, init_xattrs, &ip);
> + error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
> + if (!error)
> + error = xfs_init_new_inode(mnt_userns, tp, dp, ino, mode,
> + is_dir ? 2 : 1, rdev, prid, init_xattrs, &ip);
> if (error)
> goto out_trans_cancel;
>
> /*
> * Now we join the directory inode to the transaction. We do not do it
> - * earlier because xfs_dir_ialloc might commit the previous transaction
> + * earlier because xfs_dialloc might commit the previous transaction
> * (and release all the locks). An error from here on will result in
> * the transaction cancel unlocking dp so don't do it explicitly in the
> * error path.
> @@ -1143,6 +1098,7 @@ xfs_create_tmpfile(
> struct xfs_dquot *pdqp = NULL;
> struct xfs_trans_res *tres;
> uint resblks;
> + xfs_ino_t ino;
>
> if (XFS_FORCED_SHUTDOWN(mp))
> return -EIO;
> @@ -1167,8 +1123,10 @@ xfs_create_tmpfile(
> if (error)
> goto out_release_dquots;
>
> - error = xfs_dir_ialloc(mnt_userns, &tp, dp, mode, 0, 0, prid,
> - false, &ip);
> + error = xfs_dialloc(&tp, dp->i_ino, mode, &ino);
> + if (!error)
> + error = xfs_init_new_inode(mnt_userns, tp, dp, ino, mode,
> + 0, 0, prid, false, &ip);
> if (error)
> goto out_trans_cancel;
>
> diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> index ca826cfba91c..4b6703dbffb8 100644
> --- a/fs/xfs/xfs_inode.h
> +++ b/fs/xfs/xfs_inode.h
> @@ -431,11 +431,10 @@ void xfs_lock_two_inodes(struct xfs_inode *ip0, uint ip0_mode,
> xfs_extlen_t xfs_get_extsz_hint(struct xfs_inode *ip);
> xfs_extlen_t xfs_get_cowextsz_hint(struct xfs_inode *ip);
>
> -int xfs_dir_ialloc(struct user_namespace *mnt_userns,
> - struct xfs_trans **tpp, struct xfs_inode *dp,
> - umode_t mode, xfs_nlink_t nlink, dev_t dev,
> - prid_t prid, bool need_xattr,
> - struct xfs_inode **ipp);
> +int xfs_init_new_inode(struct user_namespace *mnt_userns, struct xfs_trans *tp,
> + struct xfs_inode *pip, xfs_ino_t ino, umode_t mode,
> + xfs_nlink_t nlink, dev_t rdev, prid_t prid, bool init_xattrs,
> + struct xfs_inode **ipp);
>
> static inline int
> xfs_itruncate_extents(
> diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
> index f7baf4dc2554..fe341f3fd419 100644
> --- a/fs/xfs/xfs_qm.c
> +++ b/fs/xfs/xfs_qm.c
> @@ -24,6 +24,7 @@
> #include "xfs_icache.h"
> #include "xfs_error.h"
> #include "xfs_ag.h"
> +#include "xfs_ialloc.h"
>
> /*
> * The global quota manager. There is only one of these for the entire
> @@ -788,8 +789,12 @@ xfs_qm_qino_alloc(
> return error;
>
> if (need_alloc) {
> - error = xfs_dir_ialloc(&init_user_ns, &tp, NULL, S_IFREG, 1, 0,
> - 0, false, ipp);
> + xfs_ino_t ino;
> +
> + error = xfs_dialloc(&tp, 0, S_IFREG, &ino);
> + if (!error)
> + error = xfs_init_new_inode(&init_user_ns, tp, NULL, ino,
> + S_IFREG, 1, 0, 0, false, ipp);
> if (error) {
> xfs_trans_cancel(tp);
> return error;
> diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
> index b4fa70282383..44596c31f4c9 100644
> --- a/fs/xfs/xfs_symlink.c
> +++ b/fs/xfs/xfs_symlink.c
> @@ -21,6 +21,7 @@
> #include "xfs_trans_space.h"
> #include "xfs_trace.h"
> #include "xfs_trans.h"
> +#include "xfs_ialloc.h"
>
> /* ----- Kernel only functions below ----- */
> int
> @@ -161,6 +162,7 @@ xfs_symlink(
> struct xfs_dquot *gdqp = NULL;
> struct xfs_dquot *pdqp = NULL;
> uint resblks;
> + xfs_ino_t ino;
>
> *ipp = NULL;
>
> @@ -223,8 +225,11 @@ xfs_symlink(
> /*
> * Allocate an inode for the symlink.
> */
> - error = xfs_dir_ialloc(mnt_userns, &tp, dp, S_IFLNK | (mode & ~S_IFMT),
> - 1, 0, prid, false, &ip);
> + error = xfs_dialloc(&tp, dp->i_ino, S_IFLNK, &ino);
> + if (!error)
> + error = xfs_init_new_inode(mnt_userns, tp, dp, ino,
> + S_IFLNK | (mode & ~S_IFMT), 1, 0, prid,
> + false, &ip);
> if (error)
> goto out_trans_cancel;
>
> --
> 2.31.1
>