Re: [PATCH 17/29] xfs: cleanup xfs_attr_list_context

Darrick J. Wong
2020-01-21T18:31:00Z

On Tue, Jan 14, 2020 at 09:10:39AM +0100, Christoph Hellwig wrote:
> Replace the alist char pointer with a void buffer given that different
> callers use it in different ways. Use the chance to remove the typedef
> and reduce the indentation of the struct defintion so that it doesn't

"definition"

> overflow 80 char lines all over.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> fs/xfs/libxfs/xfs_attr.h | 34 +++++++++++++-------------
> fs/xfs/xfs_attr_list.c | 53 ++++++++++++++++++++--------------------
> fs/xfs/xfs_trace.h | 16 ++++++------
> fs/xfs/xfs_xattr.c | 6 ++---
> 4 files changed, 55 insertions(+), 54 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
> index 0f369399effd..0c8f7c7a6b65 100644
> --- a/fs/xfs/libxfs/xfs_attr.h
> +++ b/fs/xfs/libxfs/xfs_attr.h
> @@ -99,28 +99,28 @@ typedef struct attrlist_cursor_kern {
> typedef void (*put_listent_func_t)(struct xfs_attr_list_context *, int,
> unsigned char *, int, int);
>
> -typedef struct xfs_attr_list_context {
> - struct xfs_trans *tp;
> - struct xfs_inode *dp; /* inode */
> - struct attrlist_cursor_kern *cursor; /* position in list */
> - char *alist; /* output buffer */
> +struct xfs_attr_list_context {
> + struct xfs_trans *tp;
> + struct xfs_inode *dp; /* inode */
> + struct attrlist_cursor_kern *cursor; /* position in list */
> + void *buffer; /* output buffer */

I hope nobody ever turns on -Wpointer-arith... but hey, checkpatch
doesn't complain. With the changelog fixed,

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

--D

>
> /*
> * Abort attribute list iteration if non-zero. Can be used to pass
> * error values to the xfs_attr_list caller.
> */
> - int seen_enough;
> - bool allow_incomplete;
> -
> - ssize_t count; /* num used entries */
> - int dupcnt; /* count dup hashvals seen */
> - int bufsize; /* total buffer size */
> - int firstu; /* first used byte in buffer */
> - int flags; /* from VOP call */
> - int resynch; /* T/F: resynch with cursor */
> - put_listent_func_t put_listent; /* list output fmt function */
> - int index; /* index into output buffer */
> -} xfs_attr_list_context_t;
> + int seen_enough;
> + bool allow_incomplete;
> +
> + ssize_t count; /* num used entries */
> + int dupcnt; /* count dup hashvals seen */
> + int bufsize; /* total buffer size */
> + int firstu; /* first used byte in buffer */
> + int flags; /* from VOP call */
> + int resynch; /* T/F: resynch with cursor */
> + put_listent_func_t put_listent; /* list output fmt function */
> + int index; /* index into output buffer */
> +};
>
>
> /*========================================================================
> diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
> index ac8dc64447d6..9c4acb6dc856 100644
> --- a/fs/xfs/xfs_attr_list.c
> +++ b/fs/xfs/xfs_attr_list.c
> @@ -488,10 +488,11 @@ xfs_attr3_leaf_list_int(
> * Copy out attribute entries for attr_list(), for leaf attribute lists.
> */
> STATIC int
> -xfs_attr_leaf_list(xfs_attr_list_context_t *context)
> +xfs_attr_leaf_list(
> + struct xfs_attr_list_context *context)
> {
> - int error;
> - struct xfs_buf *bp;
> + struct xfs_buf *bp;
> + int error;
>
> trace_xfs_attr_leaf_list(context);
>
> @@ -527,11 +528,11 @@ xfs_attr_list_int_ilocked(
>
> int
> xfs_attr_list_int(
> - xfs_attr_list_context_t *context)
> + struct xfs_attr_list_context *context)
> {
> - int error;
> - xfs_inode_t *dp = context->dp;
> - uint lock_mode;
> + struct xfs_inode *dp = context->dp;
> + uint lock_mode;
> + int error;
>
> XFS_STATS_INC(dp->i_mount, xs_attr_list);
>
> @@ -557,15 +558,15 @@ xfs_attr_list_int(
> */
> STATIC void
> xfs_attr_put_listent(
> - xfs_attr_list_context_t *context,
> - int flags,
> - unsigned char *name,
> - int namelen,
> - int valuelen)
> + struct xfs_attr_list_context *context,
> + int flags,
> + unsigned char *name,
> + int namelen,
> + int valuelen)
> {
> - struct attrlist *alist = (struct attrlist *)context->alist;
> - attrlist_ent_t *aep;
> - int arraytop;
> + struct attrlist *alist = context->buffer;
> + struct attrlist_ent *aep;
> + int arraytop;
>
> ASSERT(!context->seen_enough);
> ASSERT(context->count >= 0);
> @@ -593,7 +594,7 @@ xfs_attr_put_listent(
> return;
> }
>
> - aep = (attrlist_ent_t *)&context->alist[context->firstu];
> + aep = context->buffer + context->firstu;
> aep->a_valuelen = valuelen;
> memcpy(aep->a_name, name, namelen);
> aep->a_name[namelen] = 0;
> @@ -612,15 +613,15 @@ xfs_attr_put_listent(
> */
> int
> xfs_attr_list(
> - xfs_inode_t *dp,
> - char *buffer,
> - int bufsize,
> - int flags,
> - attrlist_cursor_kern_t *cursor)
> + struct xfs_inode *dp,
> + char *buffer,
> + int bufsize,
> + int flags,
> + struct attrlist_cursor_kern *cursor)
> {
> - xfs_attr_list_context_t context;
> - struct attrlist *alist;
> - int error;
> + struct xfs_attr_list_context context;
> + struct attrlist *alist;
> + int error;
>
> /*
> * Validate the cursor.
> @@ -645,12 +646,12 @@ xfs_attr_list(
> context.cursor = cursor;
> context.resynch = 1;
> context.flags = flags;
> - context.alist = buffer;
> + context.buffer = buffer;
> context.bufsize = (bufsize & ~(sizeof(int)-1)); /* align */
> context.firstu = context.bufsize;
> context.put_listent = xfs_attr_put_listent;
>
> - alist = (struct attrlist *)context.alist;
> + alist = context.buffer;
> alist->al_count = 0;
> alist->al_more = 0;
> alist->al_offset[0] = context.bufsize;
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index a86be7f807ee..8358a92987f9 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -45,7 +45,7 @@ DECLARE_EVENT_CLASS(xfs_attr_list_class,
> __field(u32, hashval)
> __field(u32, blkno)
> __field(u32, offset)
> - __field(void *, alist)
> + __field(void *, buffer)
> __field(int, bufsize)
> __field(int, count)
> __field(int, firstu)
> @@ -58,21 +58,21 @@ DECLARE_EVENT_CLASS(xfs_attr_list_class,
> __entry->hashval = ctx->cursor->hashval;
> __entry->blkno = ctx->cursor->blkno;
> __entry->offset = ctx->cursor->offset;
> - __entry->alist = ctx->alist;
> + __entry->buffer = ctx->buffer;
> __entry->bufsize = ctx->bufsize;
> __entry->count = ctx->count;
> __entry->firstu = ctx->firstu;
> __entry->flags = ctx->flags;
> ),
> TP_printk("dev %d:%d ino 0x%llx cursor h/b/o 0x%x/0x%x/%u dupcnt %u "
> - "alist %p size %u count %u firstu %u flags %d %s",
> + "buffer %p size %u count %u firstu %u flags %d %s",
> MAJOR(__entry->dev), MINOR(__entry->dev),
> __entry->ino,
> __entry->hashval,
> __entry->blkno,
> __entry->offset,
> __entry->dupcnt,
> - __entry->alist,
> + __entry->buffer,
> __entry->bufsize,
> __entry->count,
> __entry->firstu,
> @@ -169,7 +169,7 @@ TRACE_EVENT(xfs_attr_list_node_descend,
> __field(u32, hashval)
> __field(u32, blkno)
> __field(u32, offset)
> - __field(void *, alist)
> + __field(void *, buffer)
> __field(int, bufsize)
> __field(int, count)
> __field(int, firstu)
> @@ -184,7 +184,7 @@ TRACE_EVENT(xfs_attr_list_node_descend,
> __entry->hashval = ctx->cursor->hashval;
> __entry->blkno = ctx->cursor->blkno;
> __entry->offset = ctx->cursor->offset;
> - __entry->alist = ctx->alist;
> + __entry->buffer = ctx->buffer;
> __entry->bufsize = ctx->bufsize;
> __entry->count = ctx->count;
> __entry->firstu = ctx->firstu;
> @@ -193,7 +193,7 @@ TRACE_EVENT(xfs_attr_list_node_descend,
> __entry->bt_before = be32_to_cpu(btree->before);
> ),
> TP_printk("dev %d:%d ino 0x%llx cursor h/b/o 0x%x/0x%x/%u dupcnt %u "
> - "alist %p size %u count %u firstu %u flags %d %s "
> + "buffer %p size %u count %u firstu %u flags %d %s "
> "node hashval %u, node before %u",
> MAJOR(__entry->dev), MINOR(__entry->dev),
> __entry->ino,
> @@ -201,7 +201,7 @@ TRACE_EVENT(xfs_attr_list_node_descend,
> __entry->blkno,
> __entry->offset,
> __entry->dupcnt,
> - __entry->alist,
> + __entry->buffer,
> __entry->bufsize,
> __entry->count,
> __entry->firstu,
> diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
> index c9c44f8aebed..8880dee3400f 100644
> --- a/fs/xfs/xfs_xattr.c
> +++ b/fs/xfs/xfs_xattr.c
> @@ -132,7 +132,7 @@ __xfs_xattr_put_listent(
> if (context->count < 0 || context->seen_enough)
> return;
>
> - if (!context->alist)
> + if (!context->buffer)
> goto compute_size;
>
> arraytop = context->count + prefix_len + namelen + 1;
> @@ -141,7 +141,7 @@ __xfs_xattr_put_listent(
> context->seen_enough = 1;
> return;
> }
> - offset = (char *)context->alist + context->count;
> + offset = context->buffer + context->count;
> strncpy(offset, prefix, prefix_len);
> offset += prefix_len;
> strncpy(offset, (char *)name, namelen); /* real name */
> @@ -227,7 +227,7 @@ xfs_vn_listxattr(
> context.dp = XFS_I(inode);
> context.cursor = &cursor;
> context.resynch = 1;
> - context.alist = size ? data : NULL;
> + context.buffer = size ? data : NULL;
> context.bufsize = size;
> context.firstu = context.bufsize;
> context.put_listent = xfs_xattr_put_listent;
> --
> 2.24.1
>