--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "dev.h"
+#include "fuse_i.h"
+#include <linux/pagemap.h>
+
+static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_notify_poll_wakeup_out outarg;
+ int err;
+
+ if (size != sizeof(outarg))
+ return -EINVAL;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ return err;
+
+ fuse_copy_finish(cs);
+ return fuse_notify_poll_wakeup(fc, &outarg);
+}
+
+static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_notify_inval_inode_out outarg;
+ int err;
+
+ if (size != sizeof(outarg))
+ return -EINVAL;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ return err;
+ fuse_copy_finish(cs);
+
+ down_read(&fc->killsb);
+ err = fuse_reverse_inval_inode(fc, outarg.ino,
+ outarg.off, outarg.len);
+ up_read(&fc->killsb);
+ return err;
+}
+
+static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_notify_inval_entry_out outarg;
+ int err;
+ char *buf;
+ struct qstr name;
+
+ if (size < sizeof(outarg))
+ return -EINVAL;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ return err;
+
+ if (outarg.namelen > fc->name_max)
+ return -ENAMETOOLONG;
+
+ err = -EINVAL;
+ if (size != sizeof(outarg) + outarg.namelen + 1)
+ return -EINVAL;
+
+ buf = kzalloc(outarg.namelen + 1, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ name.name = buf;
+ name.len = outarg.namelen;
+ err = fuse_copy_one(cs, buf, outarg.namelen + 1);
+ if (err)
+ goto err;
+ fuse_copy_finish(cs);
+ buf[outarg.namelen] = 0;
+
+ down_read(&fc->killsb);
+ err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name, outarg.flags);
+ up_read(&fc->killsb);
+err:
+ kfree(buf);
+ return err;
+}
+
+static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_notify_delete_out outarg;
+ int err;
+ char *buf;
+ struct qstr name;
+
+ if (size < sizeof(outarg))
+ return -EINVAL;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ return err;
+
+ if (outarg.namelen > fc->name_max)
+ return -ENAMETOOLONG;
+
+ if (size != sizeof(outarg) + outarg.namelen + 1)
+ return -EINVAL;
+
+ buf = kzalloc(outarg.namelen + 1, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ name.name = buf;
+ name.len = outarg.namelen;
+ err = fuse_copy_one(cs, buf, outarg.namelen + 1);
+ if (err)
+ goto err;
+ fuse_copy_finish(cs);
+ buf[outarg.namelen] = 0;
+
+ down_read(&fc->killsb);
+ err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name, 0);
+ up_read(&fc->killsb);
+err:
+ kfree(buf);
+ return err;
+}
+
+static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_notify_store_out outarg;
+ struct inode *inode;
+ struct address_space *mapping;
+ u64 nodeid;
+ int err;
+ unsigned int num;
+ loff_t file_size;
+ loff_t pos;
+ loff_t end;
+
+ if (size < sizeof(outarg))
+ return -EINVAL;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ return err;
+
+ if (size - sizeof(outarg) != outarg.size)
+ return -EINVAL;
+
+ if (outarg.offset >= MAX_LFS_FILESIZE)
+ return -EINVAL;
+
+ nodeid = outarg.nodeid;
+ pos = outarg.offset;
+ num = min(outarg.size, MAX_LFS_FILESIZE - pos);
+
+ down_read(&fc->killsb);
+
+ err = -ENOENT;
+ inode = fuse_ilookup(fc, nodeid, NULL);
+ if (!inode)
+ goto out_up_killsb;
+
+ mapping = inode->i_mapping;
+ file_size = i_size_read(inode);
+ end = pos + num;
+ if (end > file_size) {
+ file_size = end;
+ fuse_write_update_attr(inode, file_size, num);
+ }
+
+ while (num) {
+ struct folio *folio;
+ unsigned int folio_offset;
+ unsigned int nr_bytes;
+ pgoff_t index = pos >> PAGE_SHIFT;
+
+ folio = filemap_grab_folio(mapping, index);
+ err = PTR_ERR(folio);
+ if (IS_ERR(folio))
+ goto out_iput;
+
+ folio_offset = offset_in_folio(folio, pos);
+ nr_bytes = min(num, folio_size(folio) - folio_offset);
+
+ err = fuse_copy_folio(cs, &folio, folio_offset, nr_bytes, 0);
+ if (!folio_test_uptodate(folio) && !err && folio_offset == 0 &&
+ (nr_bytes == folio_size(folio) || file_size == end)) {
+ folio_zero_segment(folio, nr_bytes, folio_size(folio));
+ folio_mark_uptodate(folio);
+ }
+ folio_unlock(folio);
+ folio_put(folio);
+
+ if (err)
+ goto out_iput;
+
+ pos += nr_bytes;
+ num -= nr_bytes;
+ }
+
+ err = 0;
+
+out_iput:
+ iput(inode);
+out_up_killsb:
+ up_read(&fc->killsb);
+ return err;
+}
+
+struct fuse_retrieve_args {
+ struct fuse_args_pages ap;
+ struct fuse_notify_retrieve_in inarg;
+};
+
+static void fuse_retrieve_end(struct fuse_args *args, int error)
+{
+ struct fuse_retrieve_args *ra =
+ container_of(args, typeof(*ra), ap.args);
+
+ release_pages(ra->ap.folios, ra->ap.num_folios);
+ kfree(ra);
+}
+
+static int fuse_retrieve(struct fuse_mount *fm, struct inode *inode,
+ struct fuse_notify_retrieve_out *outarg)
+{
+ int err;
+ struct address_space *mapping = inode->i_mapping;
+ loff_t file_size;
+ unsigned int num;
+ unsigned int offset;
+ size_t total_len = 0;
+ unsigned int num_pages;
+ struct fuse_conn *fc = fm->fc;
+ struct fuse_retrieve_args *ra;
+ size_t args_size = sizeof(*ra);
+ struct fuse_args_pages *ap;
+ struct fuse_args *args;
+ loff_t pos = outarg->offset;
+
+ offset = offset_in_page(pos);
+ file_size = i_size_read(inode);
+
+ num = min(outarg->size, fc->max_write);
+ if (pos > file_size)
+ num = 0;
+ else if (num > file_size - pos)
+ num = file_size - pos;
+
+ num_pages = DIV_ROUND_UP(num + offset, PAGE_SIZE);
+ num_pages = min(num_pages, fc->max_pages);
+ num = min(num, num_pages << PAGE_SHIFT);
+
+ args_size += num_pages * (sizeof(ap->folios[0]) + sizeof(ap->descs[0]));
+
+ ra = kzalloc(args_size, GFP_KERNEL);
+ if (!ra)
+ return -ENOMEM;
+
+ ap = &ra->ap;
+ ap->folios = (void *) (ra + 1);
+ ap->descs = (void *) (ap->folios + num_pages);
+
+ args = &ap->args;
+ args->nodeid = outarg->nodeid;
+ args->opcode = FUSE_NOTIFY_REPLY;
+ args->in_numargs = 3;
+ args->in_pages = true;
+ args->end = fuse_retrieve_end;
+
+ while (num && ap->num_folios < num_pages) {
+ struct folio *folio;
+ unsigned int folio_offset;
+ unsigned int nr_bytes;
+ pgoff_t index = pos >> PAGE_SHIFT;
+
+ folio = filemap_get_folio(mapping, index);
+ if (IS_ERR(folio))
+ break;
+
+ folio_offset = offset_in_folio(folio, pos);
+ nr_bytes = min(folio_size(folio) - folio_offset, num);
+
+ ap->folios[ap->num_folios] = folio;
+ ap->descs[ap->num_folios].offset = folio_offset;
+ ap->descs[ap->num_folios].length = nr_bytes;
+ ap->num_folios++;
+
+ pos += nr_bytes;
+ num -= nr_bytes;
+ total_len += nr_bytes;
+ }
+ ra->inarg.offset = outarg->offset;
+ ra->inarg.size = total_len;
+ fuse_set_zero_arg0(args);
+ args->in_args[1].size = sizeof(ra->inarg);
+ args->in_args[1].value = &ra->inarg;
+ args->in_args[2].size = total_len;
+
+ err = fuse_simple_notify_reply(fm, args, outarg->notify_unique);
+ if (err)
+ fuse_retrieve_end(args, err);
+
+ return err;
+}
+
+static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_notify_retrieve_out outarg;
+ struct fuse_mount *fm;
+ struct inode *inode;
+ u64 nodeid;
+ int err;
+
+ if (size != sizeof(outarg))
+ return -EINVAL;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ return err;
+
+ fuse_copy_finish(cs);
+
+ if (outarg.offset >= MAX_LFS_FILESIZE)
+ return -EINVAL;
+
+ down_read(&fc->killsb);
+ err = -ENOENT;
+ nodeid = outarg.nodeid;
+
+ inode = fuse_ilookup(fc, nodeid, &fm);
+ if (inode) {
+ err = fuse_retrieve(fm, inode, &outarg);
+ iput(inode);
+ }
+ up_read(&fc->killsb);
+
+ return err;
+}
+
+static int fuse_notify_resend(struct fuse_conn *fc)
+{
+ fuse_chan_resend(fc->chan);
+ return 0;
+}
+
+/*
+ * Increments the fuse connection epoch. This will result of dentries from
+ * previous epochs to be invalidated. Additionally, if inval_wq is set, a work
+ * queue is scheduled to trigger the invalidation.
+ */
+static int fuse_notify_inc_epoch(struct fuse_conn *fc)
+{
+ atomic_inc(&fc->epoch);
+ if (inval_wq)
+ schedule_work(&fc->epoch_work);
+
+ return 0;
+}
+
+static int fuse_notify_prune(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_notify_prune_out outarg;
+ const unsigned int batch = 512;
+ u64 *nodeids __free(kfree) = kmalloc(sizeof(u64) * batch, GFP_KERNEL);
+ unsigned int num, i;
+ int err;
+
+ if (!nodeids)
+ return -ENOMEM;
+
+ if (size < sizeof(outarg))
+ return -EINVAL;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ return err;
+
+ if (size - sizeof(outarg) != array_size(outarg.count, sizeof(u64)))
+ return -EINVAL;
+
+ for (; outarg.count; outarg.count -= num) {
+ num = min(batch, outarg.count);
+ err = fuse_copy_one(cs, nodeids, num * sizeof(u64));
+ if (err)
+ return err;
+
+ scoped_guard(rwsem_read, &fc->killsb) {
+ for (i = 0; i < num; i++)
+ fuse_try_prune_one_inode(fc, nodeids[i]);
+ }
+ }
+ return 0;
+}
+
+int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
+ unsigned int size, struct fuse_copy_state *cs)
+{
+ switch (code) {
+ case FUSE_NOTIFY_POLL:
+ return fuse_notify_poll(fc, size, cs);
+
+ case FUSE_NOTIFY_INVAL_INODE:
+ return fuse_notify_inval_inode(fc, size, cs);
+
+ case FUSE_NOTIFY_INVAL_ENTRY:
+ return fuse_notify_inval_entry(fc, size, cs);
+
+ case FUSE_NOTIFY_STORE:
+ return fuse_notify_store(fc, size, cs);
+
+ case FUSE_NOTIFY_RETRIEVE:
+ return fuse_notify_retrieve(fc, size, cs);
+
+ case FUSE_NOTIFY_DELETE:
+ return fuse_notify_delete(fc, size, cs);
+
+ case FUSE_NOTIFY_RESEND:
+ return fuse_notify_resend(fc);
+
+ case FUSE_NOTIFY_INC_EPOCH:
+ return fuse_notify_inc_epoch(fc);
+
+ case FUSE_NOTIFY_PRUNE:
+ return fuse_notify_prune(fc, size, cs);
+
+ default:
+ return -EINVAL;
+ }
+}
projects / thirdparty / kernel / linux.git / commitdiff
