Merge tag 'erofs-for-6.16-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs

Pull erofs fixes from Gao Xiang:
 "Fix for a cache aliasing issue by adding missing flush_dcache_folio(),
  which causes execution failures on some arm32 setups.

  Fix for large compressed fragments, which could be generated by
  -Eall-fragments option (but should be rare) and was rejected by
  mistake due to an on-disk hardening commit.

  The remaining ones are small fixes. Summary:

   - Address cache aliasing for mappable page cache folios

   - Allow readdir() to be interrupted

   - Fix large fragment handling which was errored out by mistake

   - Add missing tracepoints

   - Use memcpy_to_folio() to replace copy_to_iter() for inline data"

* tag 'erofs-for-6.16-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: fix large fragment handling
  erofs: allow readdir() to be interrupted
  erofs: address D-cache aliasing
  erofs: use memcpy_to_folio() to replace copy_to_iter()
  erofs: fix to add missing tracepoint in erofs_read_folio()
  erofs: fix to add missing tracepoint in erofs_readahead()

Author: torvalds

fs/erofs/data.c

@@ -214,9 +214,11 @@ int erofs_map_dev(struct super_block *sb, struct erofs_map_dev *map)
 
 /*
  * bit 30: I/O error occurred on this folio
+ * bit 29: CPU has dirty data in D-cache (needs aliasing handling);
  * bit 0 - 29: remaining parts to complete this folio
  */
-#define EROFS_ONLINEFOLIO_EIO			(1 << 30)
+#define EROFS_ONLINEFOLIO_EIO		30
+#define EROFS_ONLINEFOLIO_DIRTY		29
 
 void erofs_onlinefolio_init(struct folio *folio)
 {
@@ -233,19 +235,23 @@ void erofs_onlinefolio_split(struct folio *folio)
 	atomic_inc((atomic_t *)&folio->private);
 }
 
-void erofs_onlinefolio_end(struct folio *folio, int err)
+void erofs_onlinefolio_end(struct folio *folio, int err, bool dirty)
 {
 	int orig, v;
 
 	do {
 		orig = atomic_read((atomic_t *)&folio->private);
-		v = (orig - 1) | (err ? EROFS_ONLINEFOLIO_EIO : 0);
+		DBG_BUGON(orig <= 0);
+		v = dirty << EROFS_ONLINEFOLIO_DIRTY;
+		v |= (orig - 1) | (!!err << EROFS_ONLINEFOLIO_EIO);
 	} while (atomic_cmpxchg((atomic_t *)&folio->private, orig, v) != orig);
 
-	if (v & ~EROFS_ONLINEFOLIO_EIO)
+	if (v & (BIT(EROFS_ONLINEFOLIO_DIRTY) - 1))
 		return;
 	folio->private = 0;
-	folio_end_read(folio, !(v & EROFS_ONLINEFOLIO_EIO));
+	if (v & BIT(EROFS_ONLINEFOLIO_DIRTY))
+		flush_dcache_folio(folio);
+	folio_end_read(folio, !(v & BIT(EROFS_ONLINEFOLIO_EIO)));
 }
 
 static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
@@ -351,11 +357,16 @@ int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
  */
 static int erofs_read_folio(struct file *file, struct folio *folio)
 {
+	trace_erofs_read_folio(folio, true);
+
 	return iomap_read_folio(folio, &erofs_iomap_ops);
 }
 
 static void erofs_readahead(struct readahead_control *rac)
 {
+	trace_erofs_readahead(rac->mapping->host, readahead_index(rac),
+					readahead_count(rac), true);
+
 	return iomap_readahead(rac, &erofs_iomap_ops);
 }
 

fs/erofs/decompressor.c

@@ -301,13 +301,11 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
 		cur = min(cur, rq->outputsize);
 		if (cur && rq->out[0]) {
 			kin = kmap_local_page(rq->in[nrpages_in - 1]);
-			if (rq->out[0] == rq->in[nrpages_in - 1]) {
+			if (rq->out[0] == rq->in[nrpages_in - 1])
 				memmove(kin + rq->pageofs_out, kin + pi, cur);
-				flush_dcache_page(rq->out[0]);
-			} else {
+			else
 				memcpy_to_page(rq->out[0], rq->pageofs_out,
 					       kin + pi, cur);
-			}
 			kunmap_local(kin);
 		}
 		rq->outputsize -= cur;
@@ -325,14 +323,12 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
 			po = (rq->pageofs_out + cur + pi) & ~PAGE_MASK;
 			DBG_BUGON(no >= nrpages_out);
 			cnt = min(insz - pi, PAGE_SIZE - po);
-			if (rq->out[no] == rq->in[ni]) {
+			if (rq->out[no] == rq->in[ni])
 				memmove(kin + po,
 					kin + rq->pageofs_in + pi, cnt);
-				flush_dcache_page(rq->out[no]);
-			} else if (rq->out[no]) {
+			else if (rq->out[no])
 				memcpy_to_page(rq->out[no], po,
 					       kin + rq->pageofs_in + pi, cnt);
-			}
 			pi += cnt;
 		} while (pi < insz);
 		kunmap_local(kin);

fs/erofs/dir.c

@@ -58,6 +58,11 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx)
 		struct erofs_dirent *de;
 		unsigned int nameoff, maxsize;
 
+		if (fatal_signal_pending(current)) {
+			err = -ERESTARTSYS;
+			break;
+		}
+
 		de = erofs_bread(&buf, dbstart, true);
 		if (IS_ERR(de)) {
 			erofs_err(sb, "failed to readdir of logical block %llu of nid %llu",
@@ -88,6 +93,7 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx)
 			break;
 		ctx->pos = dbstart + maxsize;
 		ofs = 0;
+		cond_resched();
 	}
 	erofs_put_metabuf(&buf);
 	if (EROFS_I(dir)->dot_omitted && ctx->pos == dir->i_size) {

fs/erofs/fileio.c

@@ -38,7 +38,7 @@ static void erofs_fileio_ki_complete(struct kiocb *iocb, long ret)
 	} else {
 		bio_for_each_folio_all(fi, &rq->bio) {
 			DBG_BUGON(folio_test_uptodate(fi.folio));
-			erofs_onlinefolio_end(fi.folio, ret);
+			erofs_onlinefolio_end(fi.folio, ret, false);
 		}
 	}
 	bio_uninit(&rq->bio);
@@ -96,8 +96,6 @@ static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio)
 	struct erofs_map_blocks *map = &io->map;
 	unsigned int cur = 0, end = folio_size(folio), len, attached = 0;
 	loff_t pos = folio_pos(folio), ofs;
-	struct iov_iter iter;
-	struct bio_vec bv;
 	int err = 0;
 
 	erofs_onlinefolio_init(folio);
@@ -122,13 +120,7 @@ static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio)
 				err = PTR_ERR(src);
 				break;
 			}
-			bvec_set_folio(&bv, folio, len, cur);
-			iov_iter_bvec(&iter, ITER_DEST, &bv, 1, len);
-			if (copy_to_iter(src, len, &iter) != len) {
-				erofs_put_metabuf(&buf);
-				err = -EIO;
-				break;
-			}
+			memcpy_to_folio(folio, cur, src, len);
 			erofs_put_metabuf(&buf);
 		} else if (!(map->m_flags & EROFS_MAP_MAPPED)) {
 			folio_zero_segment(folio, cur, cur + len);
@@ -162,7 +154,7 @@ static int erofs_fileio_scan_folio(struct erofs_fileio *io, struct folio *folio)
 		}
 		cur += len;
 	}
-	erofs_onlinefolio_end(folio, err);
+	erofs_onlinefolio_end(folio, err, false);
 	return err;
 }
 

fs/erofs/internal.h

@@ -315,10 +315,12 @@ static inline struct folio *erofs_grab_folio_nowait(struct address_space *as,
 /* The length of extent is full */
 #define EROFS_MAP_FULL_MAPPED	0x0008
 /* Located in the special packed inode */
-#define EROFS_MAP_FRAGMENT	0x0010
+#define __EROFS_MAP_FRAGMENT	0x0010
 /* The extent refers to partial decompressed data */
 #define EROFS_MAP_PARTIAL_REF	0x0020
 
+#define EROFS_MAP_FRAGMENT	(EROFS_MAP_MAPPED | __EROFS_MAP_FRAGMENT)
+
 struct erofs_map_blocks {
 	struct erofs_buf buf;
 
@@ -390,7 +392,7 @@ int erofs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 int erofs_map_blocks(struct inode *inode, struct erofs_map_blocks *map);
 void erofs_onlinefolio_init(struct folio *folio);
 void erofs_onlinefolio_split(struct folio *folio);
-void erofs_onlinefolio_end(struct folio *folio, int err);
+void erofs_onlinefolio_end(struct folio *folio, int err, bool dirty);
 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid);
 int erofs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, u32 request_mask,

fs/erofs/zdata.c

@@ -1034,7 +1034,7 @@ static int z_erofs_scan_folio(struct z_erofs_frontend *f,
 		if (!(map->m_flags & EROFS_MAP_MAPPED)) {
 			folio_zero_segment(folio, cur, end);
 			tight = false;
-		} else if (map->m_flags & EROFS_MAP_FRAGMENT) {
+		} else if (map->m_flags & __EROFS_MAP_FRAGMENT) {
 			erofs_off_t fpos = offset + cur - map->m_la;
 
 			err = z_erofs_read_fragment(inode->i_sb, folio, cur,
@@ -1091,7 +1091,7 @@ static int z_erofs_scan_folio(struct z_erofs_frontend *f,
 			tight = (bs == PAGE_SIZE);
 		}
 	} while ((end = cur) > 0);
-	erofs_onlinefolio_end(folio, err);
+	erofs_onlinefolio_end(folio, err, false);
 	return err;
 }
 
@@ -1196,7 +1196,7 @@ static void z_erofs_fill_other_copies(struct z_erofs_backend *be, int err)
 			cur += len;
 		}
 		kunmap_local(dst);
-		erofs_onlinefolio_end(page_folio(bvi->bvec.page), err);
+		erofs_onlinefolio_end(page_folio(bvi->bvec.page), err, true);
 		list_del(p);
 		kfree(bvi);
 	}
@@ -1355,7 +1355,7 @@ static int z_erofs_decompress_pcluster(struct z_erofs_backend *be, int err)
 
 		DBG_BUGON(z_erofs_page_is_invalidated(page));
 		if (!z_erofs_is_shortlived_page(page)) {
-			erofs_onlinefolio_end(page_folio(page), err);
+			erofs_onlinefolio_end(page_folio(page), err, true);
 			continue;
 		}
 		if (pcl->algorithmformat != Z_EROFS_COMPRESSION_LZ4) {

fs/erofs/zmap.c

@@ -413,8 +413,7 @@ static int z_erofs_map_blocks_fo(struct inode *inode,
 	    !vi->z_tailextent_headlcn) {
 		map->m_la = 0;
 		map->m_llen = inode->i_size;
-		map->m_flags = EROFS_MAP_MAPPED |
-			EROFS_MAP_FULL_MAPPED | EROFS_MAP_FRAGMENT;
+		map->m_flags = EROFS_MAP_FRAGMENT;
 		return 0;
 	}
 	initial_lcn = ofs >> lclusterbits;
@@ -489,7 +488,7 @@ static int z_erofs_map_blocks_fo(struct inode *inode,
 			goto unmap_out;
 		}
 	} else if (fragment && m.lcn == vi->z_tailextent_headlcn) {
-		map->m_flags |= EROFS_MAP_FRAGMENT;
+		map->m_flags = EROFS_MAP_FRAGMENT;
 	} else {
 		map->m_pa = erofs_pos(sb, m.pblk);
 		err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
@@ -617,7 +616,7 @@ static int z_erofs_map_blocks_ext(struct inode *inode,
 	if (lstart < lend) {
 		map->m_la = lstart;
 		if (last && (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)) {
-			map->m_flags |= EROFS_MAP_MAPPED | EROFS_MAP_FRAGMENT;
+			map->m_flags = EROFS_MAP_FRAGMENT;
 			vi->z_fragmentoff = map->m_plen;
 			if (recsz > offsetof(struct z_erofs_extent, pstart_lo))
 				vi->z_fragmentoff |= map->m_pa << 32;
@@ -797,7 +796,7 @@ static int z_erofs_iomap_begin_report(struct inode *inode, loff_t offset,
 	iomap->length = map.m_llen;
 	if (map.m_flags & EROFS_MAP_MAPPED) {
 		iomap->type = IOMAP_MAPPED;
-		iomap->addr = map.m_flags & EROFS_MAP_FRAGMENT ?
+		iomap->addr = map.m_flags & __EROFS_MAP_FRAGMENT ?
 			      IOMAP_NULL_ADDR : map.m_pa;
 	} else {
 		iomap->type = IOMAP_HOLE;