在 2020年08月18日 07:40, HAGIO KAZUHITO(萩尾 一仁) 写道:
> On kernels that contain commit 1008fe6dc36d ("block: remove the all_bdevs
> list"), without the patch, the "kmem -i" option fails halfway with the
> error message 'kmem: cannot resolve: "all_bdevs"'.
>
> Signed-off-by: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
> ---
> # sorry, resending this because I sent with inappropriate setting..
>
> defs.h | 2 ++
> memory.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> symbols.c | 4 ++++
> 3 files changed, 64 insertions(+)
>
> diff --git a/defs.h b/defs.h
> index 17e98763362b..dfc09bc86618 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -2089,6 +2089,8 @@ struct offset_table { /* stash of commonly-used offsets */
> long size_class_size;
> long gendisk_private_data;
> long zram_table_entry;
> + long super_block_s_inodes;
> + long inode_i_sb_list;
> };
>
> struct size_table { /* stash of commonly-used sizes */
> diff --git a/memory.c b/memory.c
> index 2bea1288251a..c951827162cb 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -252,6 +252,7 @@ static ulonglong get_vm_flags(char *);
> static void PG_reserved_flag_init(void);
> static void PG_slab_flag_init(void);
> static ulong nr_blockdev_pages(void);
> +static ulong nr_blockdev_pages_v2(void);
> void sparse_mem_init(void);
> void dump_mem_sections(int);
> void dump_memory_blocks(int);
> @@ -501,6 +502,9 @@ vm_init(void)
> if (INVALID_MEMBER(address_space_nrpages))
> MEMBER_OFFSET_INIT(address_space_nrpages, "address_space", "__nrpages");
>
> + MEMBER_OFFSET_INIT(super_block_s_inodes, "super_block", "s_inodes");
> + MEMBER_OFFSET_INIT(inode_i_sb_list, "inode", "i_sb_list");
> +
> MEMBER_OFFSET_INIT(gendisk_major, "gendisk", "major");
> MEMBER_OFFSET_INIT(gendisk_fops, "gendisk", "fops");
> MEMBER_OFFSET_INIT(gendisk_disk_name, "gendisk", "disk_name");
> @@ -8608,6 +8612,9 @@ nr_blockdev_pages(void)
> ulong nrpages;
> char *block_device_buf, *inode_buf, *address_space_buf;
>
> + if (!kernel_symbol_exists("all_bdevs"))
> + return nr_blockdev_pages_v2();
> +
> ld = &list_data;
> BZERO(ld, sizeof(struct list_data));
> get_symbol_data("all_bdevs", sizeof(void *), &ld->start);
> @@ -8652,6 +8659,57 @@ nr_blockdev_pages(void)
> }
>
> /*
> + * Emulate 5.9 nr_blockdev_pages() function.
> + */
> +static ulong
> +nr_blockdev_pages_v2(void)
> +{
> + struct list_data list_data, *ld;
> + ulong bd_sb, address_space;
> + ulong nrpages;
> + int i, inode_count;
> + char *inode_buf, *address_space_buf;
> +
> + ld = &list_data;
> + BZERO(ld, sizeof(struct list_data));
> +
> + get_symbol_data("blockdev_superblock", sizeof(void *), &bd_sb);
> + readmem(bd_sb + OFFSET(super_block_s_inodes), KVADDR, &ld->start,
> + sizeof(ulong), "blockdev_superblock.s_inodes", FAULT_ON_ERROR);
> +
> + if (empty_list(ld->start))
> + return 0;
> + ld->flags |= LIST_ALLOCATE;
> + ld->end = bd_sb + OFFSET(super_block_s_inodes);
> + ld->list_head_offset = OFFSET(inode_i_sb_list);
> +
> + inode_buf = GETBUF(SIZE(inode));
> + address_space_buf = GETBUF(SIZE(address_space));
> +
> + inode_count = do_list(ld);
> +
> + /*
> + * go through the s_inodes list, emulating:
> + *
> + * ret += inode->i_mapping->nrpages;
> + */
> + for (i = nrpages = 0; i < inode_count; i++) {
> + readmem(ld->list_ptr[i], KVADDR, inode_buf, SIZE(inode), "inode buffer",
> + FAULT_ON_ERROR);
> + address_space = ULONG(inode_buf + OFFSET(inode_i_mapping));
> + readmem(address_space, KVADDR, address_space_buf, SIZE(address_space),
> + "address_space buffer", FAULT_ON_ERROR);
> + nrpages += ULONG(address_space_buf + OFFSET(address_space_nrpages));
> + }
> +
> + FREEBUF(ld->list_ptr);
> + FREEBUF(inode_buf);
> + FREEBUF(address_space_buf);
> +
> + return nrpages;
> +}
> +
> +/*
> * dump_vmlist() displays information from the vmlist.
> */
>
> diff --git a/symbols.c b/symbols.c
> index 2fecaee093a2..123ed00913e1 100644
> --- a/symbols.c
> +++ b/symbols.c
> @@ -9452,6 +9452,8 @@ dump_offset_table(char *spec, ulong makestruct)
> OFFSET(inode_i_fop));
> fprintf(fp, " inode_i_mapping: %ld\n",
> OFFSET(inode_i_mapping));
> + fprintf(fp, " inode_i_sb_list: %ld\n",
> + OFFSET(inode_i_sb_list));
>
> fprintf(fp, " vfsmount_mnt_next: %ld\n",
> OFFSET(vfsmount_mnt_next));
> @@ -9488,6 +9490,8 @@ dump_offset_table(char *spec, ulong makestruct)
> OFFSET(super_block_s_type));
> fprintf(fp, " super_block_s_files: %ld\n",
> OFFSET(super_block_s_files));
> + fprintf(fp, " super_block_s_inodes: %ld\n",
> + OFFSET(super_block_s_inodes));
>
> fprintf(fp, " nlm_file_f_file: %ld\n",
> OFFSET(nlm_file_f_file));
>
Thanks for the patch.
Acked-by: Lianbo Jiang <lijiang@xxxxxxxxxx>
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