Re: [PATCH] erofs: use kmap_local_page() only for erofs_bread()

From: JeffleXu
Date: Tue Oct 18 2022 - 02:47:35 EST




On 10/18/22 11:55 AM, Gao Xiang wrote:
> Convert all mapped erofs_bread() users to use kmap_local_page()
> instead of kmap() or kmap_atomic().
>
> Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>

LGTM.

Reviewed-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx>

> ---
> fs/erofs/data.c | 8 ++------
> fs/erofs/internal.h | 3 +--
> fs/erofs/xattr.c | 8 ++++----
> fs/erofs/zmap.c | 4 ++--
> 4 files changed, 9 insertions(+), 14 deletions(-)
>
> diff --git a/fs/erofs/data.c b/fs/erofs/data.c
> index fe8ac0e163f7..3873395173b5 100644
> --- a/fs/erofs/data.c
> +++ b/fs/erofs/data.c
> @@ -13,9 +13,7 @@
> void erofs_unmap_metabuf(struct erofs_buf *buf)
> {
> if (buf->kmap_type == EROFS_KMAP)
> - kunmap(buf->page);
> - else if (buf->kmap_type == EROFS_KMAP_ATOMIC)
> - kunmap_atomic(buf->base);
> + kunmap_local(buf->page);
> buf->base = NULL;
> buf->kmap_type = EROFS_NO_KMAP;
> }
> @@ -54,9 +52,7 @@ void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
> }
> if (buf->kmap_type == EROFS_NO_KMAP) {
> if (type == EROFS_KMAP)
> - buf->base = kmap(page);
> - else if (type == EROFS_KMAP_ATOMIC)
> - buf->base = kmap_atomic(page);
> + buf->base = kmap_local_page(page);
> buf->kmap_type = type;
> } else if (buf->kmap_type != type) {
> DBG_BUGON(1);
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index 1701df48c446..67dc8e177211 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -253,8 +253,7 @@ static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
>
> enum erofs_kmap_type {
> EROFS_NO_KMAP, /* don't map the buffer */
> - EROFS_KMAP, /* use kmap() to map the buffer */
> - EROFS_KMAP_ATOMIC, /* use kmap_atomic() to map the buffer */
> + EROFS_KMAP, /* use kmap_local_page() to map the buffer */
> };
>
> struct erofs_buf {
> diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c
> index 8106bcb5a38d..a62fb8a3318a 100644
> --- a/fs/erofs/xattr.c
> +++ b/fs/erofs/xattr.c
> @@ -148,7 +148,7 @@ static inline int xattr_iter_fixup(struct xattr_iter *it)
>
> it->blkaddr += erofs_blknr(it->ofs);
> it->kaddr = erofs_read_metabuf(&it->buf, it->sb, it->blkaddr,
> - EROFS_KMAP_ATOMIC);
> + EROFS_KMAP);
> if (IS_ERR(it->kaddr))
> return PTR_ERR(it->kaddr);
> it->ofs = erofs_blkoff(it->ofs);
> @@ -174,7 +174,7 @@ static int inline_xattr_iter_begin(struct xattr_iter *it,
> it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs);
>
> it->kaddr = erofs_read_metabuf(&it->buf, inode->i_sb, it->blkaddr,
> - EROFS_KMAP_ATOMIC);
> + EROFS_KMAP);
> if (IS_ERR(it->kaddr))
> return PTR_ERR(it->kaddr);
> return vi->xattr_isize - xattr_header_sz;
> @@ -368,7 +368,7 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
>
> it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
> it->it.kaddr = erofs_read_metabuf(&it->it.buf, sb, blkaddr,
> - EROFS_KMAP_ATOMIC);
> + EROFS_KMAP);
> if (IS_ERR(it->it.kaddr))
> return PTR_ERR(it->it.kaddr);
> it->it.blkaddr = blkaddr;
> @@ -580,7 +580,7 @@ static int shared_listxattr(struct listxattr_iter *it)
>
> it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
> it->it.kaddr = erofs_read_metabuf(&it->it.buf, sb, blkaddr,
> - EROFS_KMAP_ATOMIC);
> + EROFS_KMAP);
> if (IS_ERR(it->it.kaddr))
> return PTR_ERR(it->it.kaddr);
> it->it.blkaddr = blkaddr;
> diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> index 0bb66927e3d0..749a5ac943f4 100644
> --- a/fs/erofs/zmap.c
> +++ b/fs/erofs/zmap.c
> @@ -178,7 +178,7 @@ static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> unsigned int advise, type;
>
> m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
> - erofs_blknr(pos), EROFS_KMAP_ATOMIC);
> + erofs_blknr(pos), EROFS_KMAP);
> if (IS_ERR(m->kaddr))
> return PTR_ERR(m->kaddr);
>
> @@ -416,7 +416,7 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> out:
> pos += lcn * (1 << amortizedshift);
> m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
> - erofs_blknr(pos), EROFS_KMAP_ATOMIC);
> + erofs_blknr(pos), EROFS_KMAP);
> if (IS_ERR(m->kaddr))
> return PTR_ERR(m->kaddr);
> return unpack_compacted_index(m, amortizedshift, pos, lookahead);

--
Thanks,
Jingbo