On Fri, May 24, 2019 at 01:33:24PM +0800, Peng Tao wrote:
> Change FUSE_REMOVEMAPPING wire protocol so that we can remove
> multiple mappings in one call.
>
> Signed-off-by: Peng Tao <[email protected]>
Hi Tao,
How about posting a patch for enabling multiple entries in
fuse_removemapping in one patch.
Lets first merge that patch in kernel and virtiofsd. And post patches
to remove mappings on truncate later? That's an optimization and
can wait a bit.
Thanks
Vivek
> ---
> fs/fuse/file.c | 85 +++++++++++++++++++++++++++++++++------
> include/uapi/linux/fuse.h | 9 ++++-
> 2 files changed, 81 insertions(+), 13 deletions(-)
>
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index 6c970d19e926..03c81baa8989 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -320,25 +320,80 @@ static int fuse_setup_one_mapping(struct inode *inode,
> return 0;
> }
>
> -static int fuse_removemapping_one(struct inode *inode,
> - struct fuse_dax_mapping *dmap)
> +static int fuse_send_removemapping_request(struct inode *inode,
> + struct fuse_removemapping_in_header *header,
> + struct fuse_removemapping_in *inargp)
> {
> struct fuse_inode *fi = get_fuse_inode(inode);
> struct fuse_conn *fc = get_fuse_conn(inode);
> - struct fuse_removemapping_in inarg;
> FUSE_ARGS(args);
>
> - memset(&inarg, 0, sizeof(inarg));
> - inarg.moffset = dmap->window_offset;
> - inarg.len = dmap->length;
> args.in.h.opcode = FUSE_REMOVEMAPPING;
> args.in.h.nodeid = fi->nodeid;
> - args.in.numargs = 1;
> - args.in.args[0].size = sizeof(inarg);
> - args.in.args[0].value = &inarg;
> + args.in.numargs = 2;
> + args.in.args[0].size = sizeof(*header);
> + args.in.args[0].value = header;
> + args.in.args[1].size = header->count * sizeof(*inargp);
> + args.in.args[1].value = inargp;
> return fuse_simple_request(fc, &args);
> }
>
> +static int fuse_removemappings(struct inode *inode, unsigned num,
> + struct list_head *to_remove)
> +{
> + struct fuse_removemapping_in *inargp, *ptr;
> + struct fuse_removemapping_in_header header;
> + struct fuse_dax_mapping *dmap;
> + int ret, i = 0;
> +
> + if (num <= FUSE_REMOVEMAPPING_MAX_ENTRY) {
> + inargp = kmalloc_array(num, sizeof(*inargp), GFP_NOIO);
> + } else {
> + inargp = kmalloc_array(FUSE_REMOVEMAPPING_MAX_ENTRY,
> + sizeof(*inargp), GFP_NOIO);
> + }
> + if (inargp == NULL)
> + return -ENOMEM;
> +
> + ptr = inargp;
> + list_for_each_entry(dmap, to_remove, list) {
> + ptr->moffset = dmap->window_offset;
> + ptr->len = dmap->length;
> + ptr++;
> + i++;
> + num--;
> + if (i >= FUSE_REMOVEMAPPING_MAX_ENTRY || num == 0) {
> + memset(&header, 0, sizeof(header));
> + header.count = i;
> + ret = fuse_send_removemapping_request(inode, &header,
> inargp);
> + if (ret)
> + goto out;
> + ptr = inargp;
> + i = 0;
> + }
> + }
> +
> +out:
> + kfree(inargp);
> + return ret;
> +}
> +
> +static int fuse_removemapping_one(struct inode *inode,
> + struct fuse_dax_mapping *dmap)
> +{
> + struct fuse_removemapping_in inarg;
> + struct fuse_removemapping_in_header header;
> +
> + memset(&header, 0, sizeof(header));
> + /* TODO: fill in header.fh when available */
> + header.count = 1;
> + memset(&inarg, 0, sizeof(inarg));
> + inarg.moffset = dmap->window_offset;
> + inarg.len = dmap->length;
> +
> + return fuse_send_removemapping_request(inode, &header, &inarg);
> +}
> +
> /*
> * It is called from evict_inode() and by that time inode is going away. So
> * this function does not take any locks like fi->i_dmap_sem for traversing
> @@ -3851,7 +3906,9 @@ static void fuse_dax_do_free_mapping_locked(struct
> fuse_conn *fc, struct fuse_da
> void fuse_dax_free_mappings_range(struct fuse_conn *fc, struct inode *inode,
> loff_t start, loff_t end)
> {
> struct fuse_inode *fi = get_fuse_inode(inode);
> - struct fuse_dax_mapping *dmap;
> + struct fuse_dax_mapping *dmap, *n;
> + int num = 0;
> + LIST_HEAD(to_remove);
>
> WARN_ON(!inode_is_locked(inode));
> WARN_ON(!rwsem_is_locked(&fi->i_mmap_sem));
> @@ -3866,9 +3923,13 @@ void fuse_dax_free_mappings_range(struct fuse_conn
> *fc, struct inode *inode, lof
> down_write(&fi->i_dmap_sem);
> while ((dmap = fuse_dax_interval_tree_iter_first(&fi->dmap_tree, start,
> end))) {
> fuse_dax_interval_tree_remove(dmap, &fi->dmap_tree);
> - fi->nr_dmaps--;
> + num++;
> + list_add(&dmap->list, &to_remove);
> + }
> + fi->nr_dmaps -= num;
> + fuse_removemappings(inode, num, &to_remove);
> + list_for_each_entry_safe(dmap, n, &to_remove, list) {
> fuse_dax_do_free_mapping_locked(fc, dmap);
> - fuse_removemapping_one(inode, dmap);
> }
> up_write(&fi->i_dmap_sem);
> }
> diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
> index dbc5013ad747..69ddedca4177 100644
> --- a/include/uapi/linux/fuse.h
> +++ b/include/uapi/linux/fuse.h
> @@ -817,13 +817,20 @@ struct fuse_setupmapping_out {
> uint64_t len[FUSE_SETUPMAPPING_ENTRIES];
> };
>
> -struct fuse_removemapping_in {
> +struct fuse_removemapping_in_header {
> /* An already open handle */
> uint64_t fh;
> + /* number of fuse_removemapping_in follows */
> + uint32_t count;
> +};
> +
> +struct fuse_removemapping_in {
> /* Offset into the dax window start the unmapping */
> uint64_t moffset;
> /* Length of mapping required */
> uint64_t len;
> };
> +#define FUSE_REMOVEMAPPING_MAX_ENTRY \
> + (PAGE_SIZE / sizeof(struct fuse_removemapping_in))
>
> #endif /* _LINUX_FUSE_H */
> --
> 2.17.1
>
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