bcachefs: Fixes for 4.19bcachefs-v4.19-backport-compat

1 files changed, 349 insertions, 43 deletions

diff --git a/fs/bcachefs/fs-io.c b/fs/bcachefs/fs-io.c
index 56cfb0d60c03..540917bb7c3c 100644
--- a/fs/bcachefs/fs-io.c
+++ b/fs/bcachefs/fs-io.c
@@ -282,13 +282,28 @@ static inline struct bch_page_state *bch2_page_state(struct page *page)
 /* for newly allocated pages: */
 static void __bch2_page_state_release(struct page *page)
 {
-	kfree(detach_page_private(page));
+	struct bch_page_state *s = __bch2_page_state(page);
+
+	if (!s)
+		return;
+
+	ClearPagePrivate(page);
+	set_page_private(page, 0);
+	put_page(page);
+	kfree(s);
 }
 
 static void bch2_page_state_release(struct page *page)
 {
-	EBUG_ON(!PageLocked(page));
-	__bch2_page_state_release(page);
+	struct bch_page_state *s = bch2_page_state(page);
+
+	if (!s)
+		return;
+
+	ClearPagePrivate(page);
+	set_page_private(page, 0);
+	put_page(page);
+	kfree(s);
 }
 
 /* for newly allocated pages: */
@@ -302,7 +317,13 @@ static struct bch_page_state *__bch2_page_state_create(struct page *page,
 		return NULL;
 
 	spin_lock_init(&s->lock);
-	attach_page_private(page, s);
+	/*
+	 * migrate_page_move_mapping() assumes that pages with private data
+	 * have their count elevated by 1.
+	 */
+	get_page(page);
+	set_page_private(page, (unsigned long) s);
+	SetPagePrivate(page);
 	return s;
 }
 
@@ -625,12 +646,18 @@ int bch2_migrate_page(struct address_space *mapping, struct page *newpage,
 	EBUG_ON(!PageLocked(page));
 	EBUG_ON(!PageLocked(newpage));
 
-	ret = migrate_page_move_mapping(mapping, newpage, page, 0);
+	ret = migrate_page_move_mapping(mapping, newpage, page, NULL, mode, 0);
 	if (ret != MIGRATEPAGE_SUCCESS)
 		return ret;
 
-	if (PagePrivate(page))
-		attach_page_private(newpage, detach_page_private(page));
+	if (PagePrivate(page)) {
+		ClearPagePrivate(page);
+		get_page(newpage);
+		set_page_private(newpage, page_private(page));
+		set_page_private(page, 0);
+		put_page(page);
+		SetPagePrivate(newpage);
+	}
 
 	if (mode != MIGRATE_SYNC_NO_COPY)
 		migrate_page_copy(newpage, page);
@@ -644,10 +671,10 @@ int bch2_migrate_page(struct address_space *mapping, struct page *newpage,
 
 static void bch2_readpages_end_io(struct bio *bio)
 {
-	struct bvec_iter_all iter;
 	struct bio_vec *bv;
+	unsigned i;
 
-	bio_for_each_segment_all(bv, bio, iter) {
+	bio_for_each_segment_all(bv, bio, i) {
 		struct page *page = bv->bv_page;
 
 		if (!bio->bi_status) {
@@ -666,29 +693,31 @@ struct readpages_iter {
 	struct address_space	*mapping;
 	struct page		**pages;
 	unsigned		nr_pages;
+	unsigned		nr_added;
 	unsigned		idx;
 	pgoff_t			offset;
 };
 
 static int readpages_iter_init(struct readpages_iter *iter,
-			       struct readahead_control *ractl)
+			       struct address_space *mapping,
+			       struct list_head *pages, unsigned nr_pages)
 {
-	unsigned i, nr_pages = readahead_count(ractl);
-
 	memset(iter, 0, sizeof(*iter));
 
-	iter->mapping	= ractl->mapping;
-	iter->offset	= readahead_index(ractl);
-	iter->nr_pages	= nr_pages;
+	iter->mapping	= mapping;
+	iter->offset	= list_last_entry(pages, struct page, lru)->index;
 
 	iter->pages = kmalloc_array(nr_pages, sizeof(struct page *), GFP_NOFS);
 	if (!iter->pages)
 		return -ENOMEM;
 
-	nr_pages = __readahead_batch(ractl, iter->pages, nr_pages);
-	for (i = 0; i < nr_pages; i++) {
-		__bch2_page_state_create(iter->pages[i], __GFP_NOFAIL);
-		put_page(iter->pages[i]);
+	while (!list_empty(pages)) {
+		struct page *page = list_last_entry(pages, struct page, lru);
+
+		__bch2_page_state_create(page, __GFP_NOFAIL);
+
+		iter->pages[iter->nr_pages++] = page;
+		list_del(&page->lru);
 	}
 
 	return 0;
@@ -696,9 +725,41 @@ static int readpages_iter_init(struct readpages_iter *iter,
 
 static inline struct page *readpage_iter_next(struct readpages_iter *iter)
 {
-	if (iter->idx >= iter->nr_pages)
-		return NULL;
+	struct page *page;
+	unsigned i;
+	int ret;
+
+	BUG_ON(iter->idx > iter->nr_added);
+	BUG_ON(iter->nr_added > iter->nr_pages);
 
+	if (iter->idx < iter->nr_added)
+		goto out;
+
+	while (1) {
+		if (iter->idx == iter->nr_pages)
+			return NULL;
+
+		ret = add_to_page_cache_lru_vec(iter->mapping,
+				iter->pages	+ iter->nr_added,
+				iter->nr_pages	- iter->nr_added,
+				iter->offset	+ iter->nr_added,
+				GFP_NOFS);
+		if (ret > 0)
+			break;
+
+		page = iter->pages[iter->nr_added];
+		iter->idx++;
+		iter->nr_added++;
+
+		__bch2_page_state_release(page);
+		put_page(page);
+	}
+
+	iter->nr_added += ret;
+
+	for (i = iter->idx; i < iter->nr_added; i++)
+		put_page(iter->pages[i]);
+out:
 	EBUG_ON(iter->pages[iter->idx]->index != iter->offset + iter->idx);
 
 	return iter->pages[iter->idx];
@@ -759,8 +820,11 @@ static void readpage_bio_extend(struct readpages_iter *iter,
 			if (!get_more)
 				break;
 
-			page = xa_load(&iter->mapping->i_pages, page_offset);
-			if (page && !xa_is_value(page))
+			rcu_read_lock();
+			page = radix_tree_lookup(&iter->mapping->i_pages, page_offset);
+			rcu_read_unlock();
+
+			if (page && !radix_tree_exceptional_entry(page))
 				break;
 
 			page = __page_cache_alloc(readahead_gfp_mask(iter->mapping));
@@ -866,9 +930,10 @@ retry:
 	bch2_bkey_buf_exit(&sk, c);
 }
 
-void bch2_readahead(struct readahead_control *ractl)
+int bch2_readpages(struct file *file, struct address_space *mapping,
+		   struct list_head *pages, unsigned nr_pages)
 {
-	struct bch_inode_info *inode = to_bch_ei(ractl->mapping->host);
+	struct bch_inode_info *inode = to_bch_ei(mapping->host);
 	struct bch_fs *c = inode->v.i_sb->s_fs_info;
 	struct bch_io_opts opts = io_opts(c, &inode->ei_inode);
 	struct btree_trans trans;
@@ -877,7 +942,7 @@ void bch2_readahead(struct readahead_control *ractl)
 	struct readpages_iter readpages_iter;
 	int ret;
 
-	ret = readpages_iter_init(&readpages_iter, ractl);
+	ret = readpages_iter_init(&readpages_iter, mapping, pages, nr_pages);
 	BUG_ON(ret);
 
 	bch2_trans_init(&trans, c, 0, 0);
@@ -912,6 +977,8 @@ void bch2_readahead(struct readahead_control *ractl)
 
 	bch2_trans_exit(&trans);
 	kfree(readpages_iter.pages);
+
+	return 0;
 }
 
 static void __bchfs_readpage(struct bch_fs *c, struct bch_read_bio *rbio,
@@ -1011,35 +1078,34 @@ static void bch2_writepage_io_done(struct closure *cl)
 					struct bch_writepage_io, cl);
 	struct bch_fs *c = io->op.c;
 	struct bio *bio = &io->op.wbio.bio;
-	struct bvec_iter_all iter;
 	struct bio_vec *bvec;
-	unsigned i;
+	unsigned i, j;
 
 	if (io->op.error) {
 		set_bit(EI_INODE_ERROR, &io->inode->ei_flags);
 
-		bio_for_each_segment_all(bvec, bio, iter) {
+		bio_for_each_segment_all(bvec, bio, i) {
 			struct bch_page_state *s;
 
 			SetPageError(bvec->bv_page);
-			mapping_set_error(bvec->bv_page->mapping, -EIO);
+			mapping_set_error(io->inode->v.i_mapping, -EIO);
 
 			s = __bch2_page_state(bvec->bv_page);
 			spin_lock(&s->lock);
-			for (i = 0; i < PAGE_SECTORS; i++)
-				s->s[i].nr_replicas = 0;
+			for (j = 0; j < PAGE_SECTORS; j++)
+				s->s[j].nr_replicas = 0;
 			spin_unlock(&s->lock);
 		}
 	}
 
 	if (io->op.flags & BCH_WRITE_WROTE_DATA_INLINE) {
-		bio_for_each_segment_all(bvec, bio, iter) {
+		bio_for_each_segment_all(bvec, bio, i) {
 			struct bch_page_state *s;
 
 			s = __bch2_page_state(bvec->bv_page);
 			spin_lock(&s->lock);
-			for (i = 0; i < PAGE_SECTORS; i++)
-				s->s[i].nr_replicas = 0;
+			for (j = 0; j < PAGE_SECTORS; j++)
+				s->s[j].nr_replicas = 0;
 			spin_unlock(&s->lock);
 		}
 	}
@@ -1063,7 +1129,7 @@ static void bch2_writepage_io_done(struct closure *cl)
 	 */
 	i_sectors_acct(c, io->inode, NULL, io->op.i_sectors_delta);
 
-	bio_for_each_segment_all(bvec, bio, iter) {
+	bio_for_each_segment_all(bvec, bio, i) {
 		struct bch_page_state *s = __bch2_page_state(bvec->bv_page);
 
 		if (atomic_dec_and_test(&s->write_count))
@@ -1217,7 +1283,7 @@ do_io:
 
 		if (w->io &&
 		    (w->io->op.res.nr_replicas != nr_replicas_this_write ||
-		     bio_full(&w->io->op.wbio.bio, PAGE_SIZE) ||
+		     bio_full(&w->io->op.wbio.bio) ||
 		     w->io->op.wbio.bio.bi_iter.bi_size + (sectors << 9) >=
 		     (BIO_MAX_PAGES * PAGE_SIZE) ||
 		     bio_end_sector(&w->io->op.wbio.bio) != sector))
@@ -1620,6 +1686,18 @@ again:
 
 /* O_DIRECT reads */
 
+static void bio_release_pages(struct bio *bio, bool mark_dirty)
+{
+	struct bio_vec *bvec;
+	unsigned i;
+
+	bio_for_each_segment_all(bvec, bio, i) {
+		if (mark_dirty && !PageCompound(bvec->bv_page))
+			set_page_dirty_lock(bvec->bv_page);
+		put_page(bvec->bv_page);
+	}
+}
+
 static void bio_check_or_release(struct bio *bio, bool check_dirty)
 {
 	if (check_dirty) {
@@ -1807,9 +1885,8 @@ static long bch2_dio_write_loop(struct dio_write *dio)
 	struct bch_inode_info *inode = file_bch_inode(req->ki_filp);
 	struct bch_fs *c = inode->v.i_sb->s_fs_info;
 	struct bio *bio = &dio->op.wbio.bio;
-	struct bvec_iter_all iter;
 	struct bio_vec *bv;
-	unsigned unaligned, iter_count;
+	unsigned i, unaligned, iter_count;
 	bool sync = dio->sync, dropped_locks;
 	long ret;
 
@@ -1820,7 +1897,7 @@ static long bch2_dio_write_loop(struct dio_write *dio)
 		iter_count = dio->iter.count;
 
 		if (kthread)
-			kthread_use_mm(dio->mm);
+			use_mm(dio->mm);
 		BUG_ON(current->faults_disabled_mapping);
 		current->faults_disabled_mapping = mapping;
 
@@ -1830,7 +1907,7 @@ static long bch2_dio_write_loop(struct dio_write *dio)
 
 		current->faults_disabled_mapping = NULL;
 		if (kthread)
-			kthread_unuse_mm(dio->mm);
+			unuse_mm(dio->mm);
 
 		/*
 		 * If the fault handler returned an error but also signalled
@@ -1863,7 +1940,7 @@ static long bch2_dio_write_loop(struct dio_write *dio)
 			 * bio_iov_iter_get_pages was only able to get <
 			 * blocksize worth of pages:
 			 */
-			bio_for_each_segment_all(bv, bio, iter)
+			bio_for_each_segment_all(bv, bio, i)
 				put_page(bv->bv_page);
 			ret = -EFAULT;
 			goto err;
@@ -1928,7 +2005,7 @@ loop:
 			i_size_write(&inode->v, req->ki_pos);
 		spin_unlock(&inode->v.i_lock);
 
-		bio_for_each_segment_all(bv, bio, iter)
+		bio_for_each_segment_all(bv, bio, i)
 			put_page(bv->bv_page);
 
 		if (dio->op.error) {
@@ -2847,6 +2924,235 @@ static void mark_range_unallocated(struct bch_inode_info *inode,
 	} while (index <= end_index);
 }
 
+static int generic_access_check_limits(struct file *file, loff_t pos,
+				       loff_t *count)
+{
+	struct inode *inode = file->f_mapping->host;
+	loff_t max_size = inode->i_sb->s_maxbytes;
+
+	if (!(file->f_flags & O_LARGEFILE))
+		max_size = MAX_NON_LFS;
+
+	if (unlikely(pos >= max_size))
+		return -EFBIG;
+	*count = min(*count, max_size - pos);
+	return 0;
+}
+
+static int generic_write_check_limits(struct file *file, loff_t pos,
+				      loff_t *count)
+{
+	loff_t limit = rlimit(RLIMIT_FSIZE);
+
+	if (limit != RLIM_INFINITY) {
+		if (pos >= limit) {
+			send_sig(SIGXFSZ, current, 0);
+			return -EFBIG;
+		}
+		*count = min(*count, limit - pos);
+	}
+
+	return generic_access_check_limits(file, pos, count);
+}
+
+static int generic_remap_checks(struct file *file_in, loff_t pos_in,
+			 struct file *file_out, loff_t pos_out,
+			 loff_t *req_count, unsigned int remap_flags)
+{
+	struct inode *inode_in = file_in->f_mapping->host;
+	struct inode *inode_out = file_out->f_mapping->host;
+	uint64_t count = *req_count;
+	uint64_t bcount;
+	loff_t size_in, size_out;
+	loff_t bs = inode_out->i_sb->s_blocksize;
+	int ret;
+
+	/* The start of both ranges must be aligned to an fs block. */
+	if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_out, bs))
+		return -EINVAL;
+
+	/* Ensure offsets don't wrap. */
+	if (pos_in + count < pos_in || pos_out + count < pos_out)
+		return -EINVAL;
+
+	size_in = i_size_read(inode_in);
+	size_out = i_size_read(inode_out);
+
+	/* Dedupe requires both ranges to be within EOF. */
+	if ((remap_flags & REMAP_FILE_DEDUP) &&
+	    (pos_in >= size_in || pos_in + count > size_in ||
+	     pos_out >= size_out || pos_out + count > size_out))
+		return -EINVAL;
+
+	/* Ensure the infile range is within the infile. */
+	if (pos_in >= size_in)
+		return -EINVAL;
+	count = min(count, size_in - (uint64_t)pos_in);
+
+	ret = generic_access_check_limits(file_in, pos_in, &count);
+	if (ret)
+		return ret;
+
+	ret = generic_write_check_limits(file_out, pos_out, &count);
+	if (ret)
+		return ret;
+
+	/*
+	 * If the user wanted us to link to the infile's EOF, round up to the
+	 * next block boundary for this check.
+	 *
+	 * Otherwise, make sure the count is also block-aligned, having
+	 * already confirmed the starting offsets' block alignment.
+	 */
+	if (pos_in + count == size_in) {
+		bcount = ALIGN(size_in, bs) - pos_in;
+	} else {
+		if (!IS_ALIGNED(count, bs))
+			count = ALIGN_DOWN(count, bs);
+		bcount = count;
+	}
+
+	/* Don't allow overlapped cloning within the same file. */
+	if (inode_in == inode_out &&
+	    pos_out + bcount > pos_in &&
+	    pos_out < pos_in + bcount)
+		return -EINVAL;
+
+	/*
+	 * We shortened the request but the caller can't deal with that, so
+	 * bounce the request back to userspace.
+	 */
+	if (*req_count != count && !(remap_flags & REMAP_FILE_CAN_SHORTEN))
+		return -EINVAL;
+
+	*req_count = count;
+	return 0;
+}
+
+static int generic_remap_check_len(struct inode *inode_in,
+				   struct inode *inode_out,
+				   loff_t pos_out,
+				   loff_t *len,
+				   unsigned int remap_flags)
+{
+	u64 blkmask = i_blocksize(inode_in) - 1;
+	loff_t new_len = *len;
+
+	if ((*len & blkmask) == 0)
+		return 0;
+
+	if ((remap_flags & REMAP_FILE_DEDUP) ||
+	    pos_out + *len < i_size_read(inode_out))
+		new_len &= ~blkmask;
+
+	if (new_len == *len)
+		return 0;
+
+	if (remap_flags & REMAP_FILE_CAN_SHORTEN) {
+		*len = new_len;
+		return 0;
+	}
+
+	return (remap_flags & REMAP_FILE_DEDUP) ? -EBADE : -EINVAL;
+}
+
+static int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
+				  struct file *file_out, loff_t pos_out,
+				  loff_t *len, unsigned int remap_flags)
+{
+	struct inode *inode_in = file_inode(file_in);
+	struct inode *inode_out = file_inode(file_out);
+	bool same_inode = (inode_in == inode_out);
+	int ret;
+
+	/* Don't touch certain kinds of inodes */
+	if (IS_IMMUTABLE(inode_out))
+		return -EPERM;
+
+	if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
+		return -ETXTBSY;
+
+	/* Don't reflink dirs, pipes, sockets... */
+	if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
+		return -EISDIR;
+	if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
+		return -EINVAL;
+
+	/* Zero length dedupe exits immediately; reflink goes to EOF. */
+	if (*len == 0) {
+		loff_t isize = i_size_read(inode_in);
+
+		if ((remap_flags & REMAP_FILE_DEDUP) || pos_in == isize)
+			return 0;
+		if (pos_in > isize)
+			return -EINVAL;
+		*len = isize - pos_in;
+		if (*len == 0)
+			return 0;
+	}
+
+	/* Check that we don't violate system file offset limits. */
+	ret = generic_remap_checks(file_in, pos_in, file_out, pos_out, len,
+			remap_flags);
+	if (ret)
+		return ret;
+
+	/* Wait for the completion of any pending IOs on both files */
+	inode_dio_wait(inode_in);
+	if (!same_inode)
+		inode_dio_wait(inode_out);
+
+	ret = filemap_write_and_wait_range(inode_in->i_mapping,
+			pos_in, pos_in + *len - 1);
+	if (ret)
+		return ret;
+
+	ret = filemap_write_and_wait_range(inode_out->i_mapping,
+			pos_out, pos_out + *len - 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * Check that the extents are the same.
+	 */
+	if (remap_flags & REMAP_FILE_DEDUP) {
+		bool		is_same = false;
+
+		ret = vfs_dedupe_file_range_compare(inode_in, pos_in,
+				inode_out, pos_out, *len, &is_same);
+		if (ret)
+			return ret;
+		if (!is_same)
+			return -EBADE;
+	}
+
+	ret = generic_remap_check_len(inode_in, inode_out, pos_out, len,
+			remap_flags);
+	if (ret)
+		return ret;
+
+	/* If can't alter the file contents, we're done. */
+	if (!(remap_flags & REMAP_FILE_DEDUP)) {
+		/* Update the timestamps, since we can alter file contents. */
+		if (!(file_out->f_mode & FMODE_NOCMTIME)) {
+			ret = file_update_time(file_out);
+			if (ret)
+				return ret;
+		}
+
+		/*
+		 * Clear the security bits if the process is not being run by
+		 * root.  This keeps people from modifying setuid and setgid
+		 * binaries.
+		 */
+		ret = file_remove_privs(file_out);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 loff_t bch2_remap_file_range(struct file *file_src, loff_t pos_src,
 			     struct file *file_dst, loff_t pos_dst,
 			     loff_t len, unsigned remap_flags)