staging: erofs: fix some issues and clean up codes

drivers/staging/erofs/data.c +14 -12

@@ -39,31 +39,44 @@ static inline void read_endio(struct bio *bio)
 }
 
 /* prio -- true is used for dir */
-struct page *erofs_get_meta_page(struct super_block *sb,
-	erofs_blk_t blkaddr, bool prio)
+struct page *__erofs_get_meta_page(struct super_block *sb,
+	erofs_blk_t blkaddr, bool prio, bool nofail)
 {
-	struct inode *bd_inode = sb->s_bdev->bd_inode;
-	struct address_space *mapping = bd_inode->i_mapping;
+	struct inode *const bd_inode = sb->s_bdev->bd_inode;
+	struct address_space *const mapping = bd_inode->i_mapping;
+	/* prefer retrying in the allocator to blindly looping below */
+	const gfp_t gfp = mapping_gfp_constraint(mapping, ~__GFP_FS) |
+		(nofail ? __GFP_NOFAIL : 0);
+	unsigned int io_retries = nofail ? EROFS_IO_MAX_RETRIES_NOFAIL : 0;
 	struct page *page;
 
 repeat:
-	page = find_or_create_page(mapping, blkaddr,
-	/*
-	 * Prefer looping in the allocator rather than here,
-	 * at least that code knows what it's doing.
-	 */
-		mapping_gfp_constraint(mapping, ~__GFP_FS) | __GFP_NOFAIL);
-
-	BUG_ON(!page || !PageLocked(page));
+	page = find_or_create_page(mapping, blkaddr, gfp);
+	if (unlikely(page == NULL)) {
+		DBG_BUGON(nofail);
+		return ERR_PTR(-ENOMEM);
+	}
+	DBG_BUGON(!PageLocked(page));
 
 	if (!PageUptodate(page)) {
 		struct bio *bio;
 		int err;

drivers/staging/erofs/data.c +0 -0

 			unlock_page(page);
 			put_page(page);
 			goto repeat;

@@ -79,10 +93,12 @@ struct page *erofs_get_meta_page(struct super_block *sb,
 
 		/* more likely a read error */
 		if (unlikely(!PageUptodate(page))) {

Quoted 40 lines · Chao Yu

drivers/staging/erofs/data.c +14 -12

@@ -39,31 +39,44 @@ static inline void read_endio(struct bio *bio)
 }
 
 /* prio -- true is used for dir */
-struct page *erofs_get_meta_page(struct super_block *sb,
-	erofs_blk_t blkaddr, bool prio)
+struct page *__erofs_get_meta_page(struct super_block *sb,
+	erofs_blk_t blkaddr, bool prio, bool nofail)
 {
-	struct inode *bd_inode = sb->s_bdev->bd_inode;
-	struct address_space *mapping = bd_inode->i_mapping;
+	struct inode *const bd_inode = sb->s_bdev->bd_inode;
+	struct address_space *const mapping = bd_inode->i_mapping;
+	/* prefer retrying in the allocator to blindly looping below */
+	const gfp_t gfp = mapping_gfp_constraint(mapping, ~__GFP_FS) |
+		(nofail ? __GFP_NOFAIL : 0);
+	unsigned int io_retries = nofail ? EROFS_IO_MAX_RETRIES_NOFAIL : 0;
 	struct page *page;
 
 repeat:
-	page = find_or_create_page(mapping, blkaddr,
-	/*
-	 * Prefer looping in the allocator rather than here,
-	 * at least that code knows what it's doing.
-	 */
-		mapping_gfp_constraint(mapping, ~__GFP_FS) | __GFP_NOFAIL);
-
-	BUG_ON(!page || !PageLocked(page));
+	page = find_or_create_page(mapping, blkaddr, gfp);
+	if (unlikely(page == NULL)) {
+		DBG_BUGON(nofail);
+		return ERR_PTR(-ENOMEM);
+	}
+	DBG_BUGON(!PageLocked(page));
 
 	if (!PageUptodate(page)) {
 		struct bio *bio;
 		int err;

drivers/staging/erofs/data.c static inline void read_endio(struct bio *bio) · line 72

Quoted 10 lines

drivers/staging/erofs/data.c +8 -1

 
-		bio = erofs_grab_bio(sb, blkaddr, 1, read_endio, true);
+		bio = erofs_grab_bio(sb, blkaddr, 1, read_endio, nofail);
+		if (unlikely(bio == NULL)) {
+			DBG_BUGON(nofail);
+			err = -ENOMEM;
+err_out:
+			unlock_page(page);
+			put_page(page);
+			return ERR_PTR(err);

Put this err_out stuff at the bottom of the function so that we don't have to do backward hops to get to it.

drivers/staging/erofs/data.c static inline void read_endio(struct bio *bio) · line 78

Quoted 7 lines

drivers/staging/erofs/data.c +4 -1

+		}
 
 		err = bio_add_page(bio, page, PAGE_SIZE, 0);
-		BUG_ON(err != PAGE_SIZE);
+		if (unlikely(err != PAGE_SIZE)) {
+			err = -EFAULT;
+			goto err_out;

                        ^^^^^^^^^^^^

Like this. Generally avoid backwards hops if you can.

Quoted 6 lines

drivers/staging/erofs/data.c +1 -0

+		}
 
 		__submit_bio(bio, REQ_OP_READ,
 			REQ_META | (prio ? REQ_PRIO : 0));

@@ -72,6 +85,7 @@ struct page *erofs_get_meta_page(struct super_block *sb,
 

drivers/staging/erofs/data.c struct page *erofs_get_meta_page(struct super_block *sb, · line 88

Quoted 3 lines

drivers/staging/erofs/data.c +1 -0

 		/* the page has been truncated by others? */
 		if (unlikely(page->mapping != mapping)) {
+unlock_repeat:

The question mark in the "truncated by others?" is a little concerning. It's slightly weird that we don't check "io_retries" on this path.

Quoted 41 lines · Chao Yu

drivers/staging/erofs/data.c +14 -12

@@ -39,31 +39,44 @@ static inline void read_endio(struct bio *bio)
 }
 
 /* prio -- true is used for dir */
-struct page *erofs_get_meta_page(struct super_block *sb,
-	erofs_blk_t blkaddr, bool prio)
+struct page *__erofs_get_meta_page(struct super_block *sb,
+	erofs_blk_t blkaddr, bool prio, bool nofail)
 {
-	struct inode *bd_inode = sb->s_bdev->bd_inode;
-	struct address_space *mapping = bd_inode->i_mapping;
+	struct inode *const bd_inode = sb->s_bdev->bd_inode;
+	struct address_space *const mapping = bd_inode->i_mapping;
+	/* prefer retrying in the allocator to blindly looping below */
+	const gfp_t gfp = mapping_gfp_constraint(mapping, ~__GFP_FS) |
+		(nofail ? __GFP_NOFAIL : 0);
+	unsigned int io_retries = nofail ? EROFS_IO_MAX_RETRIES_NOFAIL : 0;
 	struct page *page;
 
 repeat:
-	page = find_or_create_page(mapping, blkaddr,
-	/*
-	 * Prefer looping in the allocator rather than here,
-	 * at least that code knows what it's doing.
-	 */
-		mapping_gfp_constraint(mapping, ~__GFP_FS) | __GFP_NOFAIL);
-
-	BUG_ON(!page || !PageLocked(page));
+	page = find_or_create_page(mapping, blkaddr, gfp);
+	if (unlikely(page == NULL)) {
+		DBG_BUGON(nofail);
+		return ERR_PTR(-ENOMEM);
+	}
+	DBG_BUGON(!PageLocked(page));
 
 	if (!PageUptodate(page)) {
 		struct bio *bio;
 		int err;
 

drivers/staging/erofs/data.c static inline void read_endio(struct bio *bio) · line 72

Quoted 9 lines

drivers/staging/erofs/data.c +8 -1

-		bio = erofs_grab_bio(sb, blkaddr, 1, read_endio, true);
+		bio = erofs_grab_bio(sb, blkaddr, 1, read_endio, nofail);
+		if (unlikely(bio == NULL)) {
+			DBG_BUGON(nofail);
+			err = -ENOMEM;
+err_out:
+			unlock_page(page);
+			put_page(page);
+			return ERR_PTR(err);

Put this err_out stuff at the bottom of the function so that we don't have to do backward hops to get to it.

drivers/staging/erofs/data.c static inline void read_endio(struct bio *bio) · line 78

Quoted 8 lines

drivers/staging/erofs/data.c +4 -1

+		}
 
 		err = bio_add_page(bio, page, PAGE_SIZE, 0);
-		BUG_ON(err != PAGE_SIZE);
+		if (unlikely(err != PAGE_SIZE)) {
+			err = -EFAULT;
+			goto err_out;

                        ^^^^^^^^^^^^

Like this. Generally avoid backwards hops if you can.

Quoted 6 lines

drivers/staging/erofs/data.c +1 -0

+		}
 
 		__submit_bio(bio, REQ_OP_READ,
 			REQ_META | (prio ? REQ_PRIO : 0));

@@ -72,6 +85,7 @@ struct page *erofs_get_meta_page(struct super_block *sb,
 

drivers/staging/erofs/data.c struct page *erofs_get_meta_page(struct super_block *sb, · line 88

Quoted 3 lines

drivers/staging/erofs/data.c +1 -0

 		/* the page has been truncated by others? */
 		if (unlikely(page->mapping != mapping)) {
+unlock_repeat:

The question mark in the "truncated by others?" is a little concerning.

It's slightly weird that we don't check "io_retries" on this path.

Quoted 8 lines

drivers/staging/erofs/data.c +0 -0

 			unlock_page(page);
 			put_page(page);
 			goto repeat;

@@ -79,10 +93,12 @@ struct page *erofs_get_meta_page(struct super_block *sb,
 
 		/* more likely a read error */
 		if (unlikely(!PageUptodate(page))) {

drivers/staging/erofs/data.c struct page *erofs_get_meta_page(struct super_block *sb, · line 101

Quoted 10 lines

drivers/staging/erofs/data.c +6 -4

-			unlock_page(page);
-			put_page(page);
-
-			page = ERR_PTR(-EIO);
+			if (io_retries) {
+				--io_retries;
+				goto unlock_repeat;
+			}
+			err = -EIO;
+			goto err_out;

regards,
dan carpenter

From: Gao Xiang <gaoxiang25 at huawei.com>

This patch enhances the missing error handling code for xattr submodule, which improves the stability for the rare cases.

Signed-off-by Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by Chao Yu <yuchao0 at huawei.com>

Signed-off-by Chao Yu <yuchao0 at huawei.com>

---
 drivers/staging/erofs/internal.h |   6 +-
 drivers/staging/erofs/xattr.c    | 120 ++++++++++++++++++++-----------
 2 files changed, 83 insertions(+), 43 deletions(-)

drivers/staging/erofs/internal.h +3 -3

index a756abeff7e9..8951e01216e3 100644
@@ -485,10 +485,10 @@ struct erofs_map_blocks_iter {
 
 
 static inline struct page *
-erofs_get_inline_page_nofail(struct inode *inode,
-			     erofs_blk_t blkaddr)
+erofs_get_inline_page(struct inode *inode,
+		      erofs_blk_t blkaddr)
 {
-	return erofs_get_meta_page_nofail(inode->i_sb,
+	return erofs_get_meta_page(inode->i_sb,
 		blkaddr, S_ISDIR(inode->i_mode));
 }
 

drivers/staging/erofs/xattr.c +28 -17

index 2593c856b079..1b5815fc70db 100644
@@ -24,16 +24,25 @@ struct xattr_iter {
 
 static inline void xattr_iter_end(struct xattr_iter *it, bool atomic)
 {
-	/* only init_inode_xattrs use non-atomic once */
+	/* the only user of kunmap() is 'init_inode_xattrs' */
 	if (unlikely(!atomic))
 		kunmap(it->page);
 	else
 		kunmap_atomic(it->kaddr);
+
 	unlock_page(it->page);
 	put_page(it->page);
 }
 
-static void init_inode_xattrs(struct inode *inode)
+static inline void xattr_iter_end_final(struct xattr_iter *it)
+{
+	if (unlikely(it->page == NULL))
+		return;
+
+	xattr_iter_end(it, true);
+}
+
+static int init_inode_xattrs(struct inode *inode)
 {
 	struct xattr_iter it;
 	unsigned i;

@@ -44,7 +53,7 @@ static void init_inode_xattrs(struct inode *inode)
 	bool atomic_map;
 
 	if (likely(inode_has_inited_xattr(inode)))
-		return;
+		return 0;
 
 	vi = EROFS_V(inode);
 	BUG_ON(!vi->xattr_isize);

@@ -54,8 +63,9 @@ static void init_inode_xattrs(struct inode *inode)
 	it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
 	it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
 
-	it.page = erofs_get_inline_page_nofail(inode, it.blkaddr);
-	BUG_ON(IS_ERR(it.page));
+	it.page = erofs_get_inline_page(inode, it.blkaddr);
+	if (IS_ERR(it.page))
+		return PTR_ERR(it.page);
 
 	/* read in shared xattr array (non-atomic, see kmalloc below) */
 	it.kaddr = kmap(it.page);

@@ -64,9 +74,12 @@ static void init_inode_xattrs(struct inode *inode)
 	ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
 
 	vi->xattr_shared_count = ih->h_shared_count;
-	vi->xattr_shared_xattrs = (unsigned *)kmalloc_array(
-		vi->xattr_shared_count, sizeof(unsigned),
-		GFP_KERNEL | __GFP_NOFAIL);
+	vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
+						sizeof(unsigned), GFP_KERNEL);
+	if (unlikely(vi->xattr_shared_xattrs == NULL)) {
+		xattr_iter_end(&it, atomic_map);
+		return -ENOMEM;
+	}
 
 	/* let's skip ibody header */
 	it.ofs += sizeof(struct erofs_xattr_ibody_header);

@@ -77,9 +90,10 @@ static void init_inode_xattrs(struct inode *inode)
 			BUG_ON(it.ofs != EROFS_BLKSIZ);
 			xattr_iter_end(&it, atomic_map);
 
-			it.page = erofs_get_meta_page_nofail(sb,
+			it.page = erofs_get_meta_page(sb,
 				++it.blkaddr, S_ISDIR(inode->i_mode));
-			BUG_ON(IS_ERR(it.page));
+			if (IS_ERR(it.page))
+				return PTR_ERR(it.page);
 
 			it.kaddr = kmap_atomic(it.page);
 			atomic_map = true;

@@ -92,6 +106,7 @@ static void init_inode_xattrs(struct inode *inode)
 	xattr_iter_end(&it, atomic_map);
 
 	inode_set_inited_xattr(inode);
+	return 0;
 }
 
 struct xattr_iter_handlers {

@@ -101,19 +116,24 @@ struct xattr_iter_handlers {
 	void (*value)(struct xattr_iter *, unsigned, char *, unsigned);
 };
 
-static void xattr_iter_fixup(struct xattr_iter *it)
+static inline int xattr_iter_fixup(struct xattr_iter *it)
 {
-	if (unlikely(it->ofs >= EROFS_BLKSIZ)) {
-		xattr_iter_end(it, true);
+	if (likely(it->ofs < EROFS_BLKSIZ))
+		return 0;
 
-		it->blkaddr += erofs_blknr(it->ofs);
-		it->page = erofs_get_meta_page_nofail(it->sb,
-			it->blkaddr, false);
-		BUG_ON(IS_ERR(it->page));

drivers/staging/erofs/xattr.c +45 -21

 	}
+
+	it->kaddr = kmap_atomic(it->page);
+	it->ofs = erofs_blkoff(it->ofs);
+	return 0;
 }
 
 static int inline_xattr_iter_begin(struct xattr_iter *it,

@@ -134,22 +154,25 @@ static int inline_xattr_iter_begin(struct xattr_iter *it,
 	it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs);
 	it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs);
 
-	it->page = erofs_get_inline_page_nofail(inode, it->blkaddr);
-	BUG_ON(IS_ERR(it->page));
-	it->kaddr = kmap_atomic(it->page);
+	it->page = erofs_get_inline_page(inode, it->blkaddr);
+	if (IS_ERR(it->page))
+		return PTR_ERR(it->page);
 
+	it->kaddr = kmap_atomic(it->page);
 	return vi->xattr_isize - xattr_header_sz;
 }
 
 static int xattr_foreach(struct xattr_iter *it,
-	struct xattr_iter_handlers *op, unsigned *tlimit)
+	const struct xattr_iter_handlers *op, unsigned *tlimit)
 {
 	struct erofs_xattr_entry entry;
 	unsigned value_sz, processed, slice;
 	int err;
 
 	/* 0. fixup blkaddr, ofs, ipage */
-	xattr_iter_fixup(it);
+	err = xattr_iter_fixup(it);
+	if (unlikely(err))
+		return err;
 
 	/*
 	 * 1. read xattr entry to the memory,

@@ -181,7 +204,9 @@ static int xattr_foreach(struct xattr_iter *it,
 		if (it->ofs >= EROFS_BLKSIZ) {
 			BUG_ON(it->ofs > EROFS_BLKSIZ);
 
-			xattr_iter_fixup(it);
+			err = xattr_iter_fixup(it);
+			if (unlikely(err))
+				goto out;
 			it->ofs = 0;
 		}
 

@@ -213,7 +238,10 @@ static int xattr_foreach(struct xattr_iter *it,
 	while (processed < value_sz) {
 		if (it->ofs >= EROFS_BLKSIZ) {
 			BUG_ON(it->ofs > EROFS_BLKSIZ);
-			xattr_iter_fixup(it);
+
+			err = xattr_iter_fixup(it);
+			if (unlikely(err))
+				goto out;
 			it->ofs = 0;
 		}
 

@@ -273,7 +301,7 @@ static void xattr_copyvalue(struct xattr_iter *_it,
 	memcpy(it->buffer + processed, buf, len);
 }
 
-static struct xattr_iter_handlers find_xattr_handlers = {
+static const struct xattr_iter_handlers find_xattr_handlers = {
 	.entry = xattr_entrymatch,
 	.name = xattr_namematch,
 	.alloc_buffer = xattr_checkbuffer,

@@ -294,8 +322,11 @@ static int inline_getxattr(struct inode *inode, struct getxattr_iter *it)
 		ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining);
 		if (ret >= 0)
 			break;
+
+		if (unlikely(ret != -ENOATTR))	/* -ENOMEM, -EIO, etc. */
+			break;
 	}
-	xattr_iter_end(&it->it, true);
+	xattr_iter_end_final(&it->it);
 
 	return ret < 0 ? ret : it->buffer_size;
 }

@@ -318,9 +349,10 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
 			if (i)
 				xattr_iter_end(&it->it, true);
 
-			it->it.page = erofs_get_meta_page_nofail(sb,
-				blkaddr, false);
-			BUG_ON(IS_ERR(it->it.page));
+			it->it.page = erofs_get_meta_page(sb, blkaddr, false);
+			if (IS_ERR(it->it.page))
+				return PTR_ERR(it->it.page);
+
 			it->it.kaddr = kmap_atomic(it->it.page);
 			it->it.blkaddr = blkaddr;
 		}

@@ -328,9 +360,12 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
 		ret = xattr_foreach(&it->it, &find_xattr_handlers, NULL);
 		if (ret >= 0)
 			break;
+
+		if (unlikely(ret != -ENOATTR))	/* -ENOMEM, -EIO, etc. */
+			break;
 	}
 	if (vi->xattr_shared_count)
-		xattr_iter_end(&it->it, true);
+		xattr_iter_end_final(&it->it);
 
 	return ret < 0 ? ret : it->buffer_size;
 }

@@ -355,7 +390,9 @@ int erofs_getxattr(struct inode *inode, int index,
 	if (unlikely(name == NULL))
 		return -EINVAL;
 
-	init_inode_xattrs(inode);
+	ret = init_inode_xattrs(inode);
+	if (unlikely(ret < 0))
+		return ret;
 
 	it.index = index;
 

@@ -498,7 +535,7 @@ static int xattr_skipvalue(struct xattr_iter *_it,
 	return 1;
 }
 
-static struct xattr_iter_handlers list_xattr_handlers = {
+static const struct xattr_iter_handlers list_xattr_handlers = {
 	.entry = xattr_entrylist,
 	.name = xattr_namelist,
 	.alloc_buffer = xattr_skipvalue,

@@ -520,7 +557,7 @@ static int inline_listxattr(struct listxattr_iter *it)
 		if (ret < 0)
 			break;
 	}
-	xattr_iter_end(&it->it, true);
+	xattr_iter_end_final(&it->it);
 	return ret < 0 ? ret : it->buffer_ofs;
 }
 

@@ -542,9 +579,10 @@ static int shared_listxattr(struct listxattr_iter *it)
 			if (i)
 				xattr_iter_end(&it->it, true);
 
-			it->it.page = erofs_get_meta_page_nofail(sb,
-				blkaddr, false);
-			BUG_ON(IS_ERR(it->it.page));
+			it->it.page = erofs_get_meta_page(sb, blkaddr, false);
+			if (IS_ERR(it->it.page))
+				return PTR_ERR(it->it.page);
+
 			it->it.kaddr = kmap_atomic(it->it.page);
 			it->it.blkaddr = blkaddr;
 		}

@@ -554,7 +592,7 @@ static int shared_listxattr(struct listxattr_iter *it)
 			break;
 	}
 	if (vi->xattr_shared_count)
-		xattr_iter_end(&it->it, true);
+		xattr_iter_end_final(&it->it);
 
 	return ret < 0 ? ret : it->buffer_ofs;
 }

@@ -565,7 +603,9 @@ ssize_t erofs_listxattr(struct dentry *dentry,
 	int ret;
 	struct listxattr_iter it;
 
-	init_inode_xattrs(d_inode(dentry));
+	ret = init_inode_xattrs(d_inode(dentry));
+	if (unlikely(ret < 0))
+		return ret;
 
 	it.dentry = dentry;
 	it.buffer = buffer;

Quoted 137 lines · Chao Yu

From: Gao Xiang <gaoxiang25 at huawei.com>

This patch enhances the missing error handling code for xattr submodule, which improves the stability for the rare cases.

Signed-off-by Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by Chao Yu <yuchao0 at huawei.com>

Signed-off-by Chao Yu <yuchao0 at huawei.com>

---
 drivers/staging/erofs/internal.h |   6 +-
 drivers/staging/erofs/xattr.c    | 120 ++++++++++++++++++++-----------
 2 files changed, 83 insertions(+), 43 deletions(-)

drivers/staging/erofs/internal.h +3 -3

index a756abeff7e9..8951e01216e3 100644
@@ -485,10 +485,10 @@ struct erofs_map_blocks_iter {
 
 
 static inline struct page *
-erofs_get_inline_page_nofail(struct inode *inode,
-			     erofs_blk_t blkaddr)
+erofs_get_inline_page(struct inode *inode,
+		      erofs_blk_t blkaddr)
 {
-	return erofs_get_meta_page_nofail(inode->i_sb,
+	return erofs_get_meta_page(inode->i_sb,
 		blkaddr, S_ISDIR(inode->i_mode));
 }
 

drivers/staging/erofs/xattr.c +28 -17

index 2593c856b079..1b5815fc70db 100644
@@ -24,16 +24,25 @@ struct xattr_iter {
 
 static inline void xattr_iter_end(struct xattr_iter *it, bool atomic)
 {
-	/* only init_inode_xattrs use non-atomic once */
+	/* the only user of kunmap() is 'init_inode_xattrs' */
 	if (unlikely(!atomic))
 		kunmap(it->page);
 	else
 		kunmap_atomic(it->kaddr);
+
 	unlock_page(it->page);
 	put_page(it->page);
 }
 
-static void init_inode_xattrs(struct inode *inode)
+static inline void xattr_iter_end_final(struct xattr_iter *it)
+{
+	if (unlikely(it->page == NULL))
+		return;
+
+	xattr_iter_end(it, true);
+}
+
+static int init_inode_xattrs(struct inode *inode)
 {
 	struct xattr_iter it;
 	unsigned i;

@@ -44,7 +53,7 @@ static void init_inode_xattrs(struct inode *inode)
 	bool atomic_map;
 
 	if (likely(inode_has_inited_xattr(inode)))
-		return;
+		return 0;
 
 	vi = EROFS_V(inode);
 	BUG_ON(!vi->xattr_isize);

@@ -54,8 +63,9 @@ static void init_inode_xattrs(struct inode *inode)
 	it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
 	it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
 
-	it.page = erofs_get_inline_page_nofail(inode, it.blkaddr);
-	BUG_ON(IS_ERR(it.page));
+	it.page = erofs_get_inline_page(inode, it.blkaddr);
+	if (IS_ERR(it.page))
+		return PTR_ERR(it.page);
 
 	/* read in shared xattr array (non-atomic, see kmalloc below) */
 	it.kaddr = kmap(it.page);

@@ -64,9 +74,12 @@ static void init_inode_xattrs(struct inode *inode)
 	ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
 
 	vi->xattr_shared_count = ih->h_shared_count;
-	vi->xattr_shared_xattrs = (unsigned *)kmalloc_array(
-		vi->xattr_shared_count, sizeof(unsigned),
-		GFP_KERNEL | __GFP_NOFAIL);
+	vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
+						sizeof(unsigned), GFP_KERNEL);
+	if (unlikely(vi->xattr_shared_xattrs == NULL)) {
+		xattr_iter_end(&it, atomic_map);
+		return -ENOMEM;
+	}
 
 	/* let's skip ibody header */
 	it.ofs += sizeof(struct erofs_xattr_ibody_header);

@@ -77,9 +90,10 @@ static void init_inode_xattrs(struct inode *inode)
 			BUG_ON(it.ofs != EROFS_BLKSIZ);
 			xattr_iter_end(&it, atomic_map);
 
-			it.page = erofs_get_meta_page_nofail(sb,
+			it.page = erofs_get_meta_page(sb,
 				++it.blkaddr, S_ISDIR(inode->i_mode));
-			BUG_ON(IS_ERR(it.page));
+			if (IS_ERR(it.page))
+				return PTR_ERR(it.page);
 
 			it.kaddr = kmap_atomic(it.page);
 			atomic_map = true;

@@ -92,6 +106,7 @@ static void init_inode_xattrs(struct inode *inode)
 	xattr_iter_end(&it, atomic_map);
 
 	inode_set_inited_xattr(inode);
+	return 0;
 }
 
 struct xattr_iter_handlers {

@@ -101,19 +116,24 @@ struct xattr_iter_handlers {
 	void (*value)(struct xattr_iter *, unsigned, char *, unsigned);
 };
 
-static void xattr_iter_fixup(struct xattr_iter *it)
+static inline int xattr_iter_fixup(struct xattr_iter *it)
 {
-	if (unlikely(it->ofs >= EROFS_BLKSIZ)) {
-		xattr_iter_end(it, true);
+	if (likely(it->ofs < EROFS_BLKSIZ))
+		return 0;
 
-		it->blkaddr += erofs_blknr(it->ofs);
-		it->page = erofs_get_meta_page_nofail(it->sb,
-			it->blkaddr, false);
-		BUG_ON(IS_ERR(it->page));

drivers/staging/erofs/xattr.c struct xattr_iter_handlers { · line 131

Quoted 10 lines

drivers/staging/erofs/xattr.c +7 -2

+	xattr_iter_end(it, true);
 
-		it->kaddr = kmap_atomic(it->page);
-		it->ofs = erofs_blkoff(it->ofs);
+	it->blkaddr += erofs_blknr(it->ofs);
+
+	it->page = erofs_get_meta_page(it->sb, it->blkaddr, false);
+	if (IS_ERR(it->page)) {
+		it->page = NULL;
+		return PTR_ERR(it->page);

As LKP reported, we need to fix this as below:

err = PTR_ERR(it->page);
it->page = NULL;
return err;

Thanks,

Hi Chao,

Quoted 154 lines · Chao Yu

Quoted 137 lines · Chao Yu

From: Gao Xiang <gaoxiang25 at huawei.com>

This patch enhances the missing error handling code for xattr submodule, which improves the stability for the rare cases.

Signed-off-by Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by Chao Yu <yuchao0 at huawei.com>

Signed-off-by Chao Yu <yuchao0 at huawei.com>

---
 drivers/staging/erofs/internal.h |   6 +-
 drivers/staging/erofs/xattr.c    | 120 ++++++++++++++++++++-----------
 2 files changed, 83 insertions(+), 43 deletions(-)

drivers/staging/erofs/internal.h +3 -3

index a756abeff7e9..8951e01216e3 100644
@@ -485,10 +485,10 @@ struct erofs_map_blocks_iter {
 
 
 static inline struct page *
-erofs_get_inline_page_nofail(struct inode *inode,
-			     erofs_blk_t blkaddr)
+erofs_get_inline_page(struct inode *inode,
+		      erofs_blk_t blkaddr)
 {
-	return erofs_get_meta_page_nofail(inode->i_sb,
+	return erofs_get_meta_page(inode->i_sb,
 		blkaddr, S_ISDIR(inode->i_mode));
 }
 

drivers/staging/erofs/xattr.c +28 -17

index 2593c856b079..1b5815fc70db 100644
@@ -24,16 +24,25 @@ struct xattr_iter {
 
 static inline void xattr_iter_end(struct xattr_iter *it, bool atomic)
 {
-	/* only init_inode_xattrs use non-atomic once */
+	/* the only user of kunmap() is 'init_inode_xattrs' */
 	if (unlikely(!atomic))
 		kunmap(it->page);
 	else
 		kunmap_atomic(it->kaddr);
+
 	unlock_page(it->page);
 	put_page(it->page);
 }
 
-static void init_inode_xattrs(struct inode *inode)
+static inline void xattr_iter_end_final(struct xattr_iter *it)
+{
+	if (unlikely(it->page == NULL))
+		return;
+
+	xattr_iter_end(it, true);
+}
+
+static int init_inode_xattrs(struct inode *inode)
 {
 	struct xattr_iter it;
 	unsigned i;

@@ -44,7 +53,7 @@ static void init_inode_xattrs(struct inode *inode)
 	bool atomic_map;
 
 	if (likely(inode_has_inited_xattr(inode)))
-		return;
+		return 0;
 
 	vi = EROFS_V(inode);
 	BUG_ON(!vi->xattr_isize);

@@ -54,8 +63,9 @@ static void init_inode_xattrs(struct inode *inode)
 	it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
 	it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
 
-	it.page = erofs_get_inline_page_nofail(inode, it.blkaddr);
-	BUG_ON(IS_ERR(it.page));
+	it.page = erofs_get_inline_page(inode, it.blkaddr);
+	if (IS_ERR(it.page))
+		return PTR_ERR(it.page);
 
 	/* read in shared xattr array (non-atomic, see kmalloc below) */
 	it.kaddr = kmap(it.page);

@@ -64,9 +74,12 @@ static void init_inode_xattrs(struct inode *inode)
 	ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
 
 	vi->xattr_shared_count = ih->h_shared_count;
-	vi->xattr_shared_xattrs = (unsigned *)kmalloc_array(
-		vi->xattr_shared_count, sizeof(unsigned),
-		GFP_KERNEL | __GFP_NOFAIL);
+	vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count,
+						sizeof(unsigned), GFP_KERNEL);
+	if (unlikely(vi->xattr_shared_xattrs == NULL)) {
+		xattr_iter_end(&it, atomic_map);
+		return -ENOMEM;
+	}
 
 	/* let's skip ibody header */
 	it.ofs += sizeof(struct erofs_xattr_ibody_header);

@@ -77,9 +90,10 @@ static void init_inode_xattrs(struct inode *inode)
 			BUG_ON(it.ofs != EROFS_BLKSIZ);
 			xattr_iter_end(&it, atomic_map);
 
-			it.page = erofs_get_meta_page_nofail(sb,
+			it.page = erofs_get_meta_page(sb,
 				++it.blkaddr, S_ISDIR(inode->i_mode));
-			BUG_ON(IS_ERR(it.page));
+			if (IS_ERR(it.page))
+				return PTR_ERR(it.page);
 
 			it.kaddr = kmap_atomic(it.page);
 			atomic_map = true;

@@ -92,6 +106,7 @@ static void init_inode_xattrs(struct inode *inode)
 	xattr_iter_end(&it, atomic_map);
 
 	inode_set_inited_xattr(inode);
+	return 0;
 }
 
 struct xattr_iter_handlers {

@@ -101,19 +116,24 @@ struct xattr_iter_handlers {
 	void (*value)(struct xattr_iter *, unsigned, char *, unsigned);
 };
 
-static void xattr_iter_fixup(struct xattr_iter *it)
+static inline int xattr_iter_fixup(struct xattr_iter *it)
 {
-	if (unlikely(it->ofs >= EROFS_BLKSIZ)) {
-		xattr_iter_end(it, true);
+	if (likely(it->ofs < EROFS_BLKSIZ))
+		return 0;
 
-		it->blkaddr += erofs_blknr(it->ofs);
-		it->page = erofs_get_meta_page_nofail(it->sb,
-			it->blkaddr, false);
-		BUG_ON(IS_ERR(it->page));

drivers/staging/erofs/xattr.c struct xattr_iter_handlers { · line 131

Quoted 10 lines

drivers/staging/erofs/xattr.c +7 -2

+	xattr_iter_end(it, true);
 
-		it->kaddr = kmap_atomic(it->page);
-		it->ofs = erofs_blkoff(it->ofs);
+	it->blkaddr += erofs_blknr(it->ofs);
+
+	it->page = erofs_get_meta_page(it->sb, it->blkaddr, false);
+	if (IS_ERR(it->page)) {
+		it->page = NULL;
+		return PTR_ERR(it->page);

As LKP reported, we need to fix this as below:

err = PTR_ERR(it->page);
it->page = NULL;
return err;

Quoted 2 lines

Thanks,

I have seen this at
https://lists.01.org/pipermail/kbuild-all/2018-August/051187.html

I will fix it soon. Thanks for report.

Thanks,
Gao Xiang

.

drivers/staging/erofs/xattr.c +3 -7

-static void xattr_iter_fixup(struct xattr_iter *it)
+static inline int xattr_iter_fixup(struct xattr_iter *it)
 {
-	if (unlikely(it->ofs >= EROFS_BLKSIZ)) {
-		xattr_iter_end(it, true);
+	if (likely(it->ofs < EROFS_BLKSIZ))
+		return 0;
 
-		it->blkaddr += erofs_blknr(it->ofs);
-		it->page = erofs_get_meta_page_nofail(it->sb,
-			it->blkaddr, false);
-		BUG_ON(IS_ERR(it->page));

drivers/staging/erofs/xattr.c +20 -8

 	}
+
+	it->kaddr = kmap_atomic(it->page);
+	it->ofs = erofs_blkoff(it->ofs);
+	return 0;
 }
 
 static int inline_xattr_iter_begin(struct xattr_iter *it,

@@ -134,22 +154,25 @@ static int inline_xattr_iter_begin(struct xattr_iter *it,
 	it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs);
 	it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs);
 
-	it->page = erofs_get_inline_page_nofail(inode, it->blkaddr);
-	BUG_ON(IS_ERR(it->page));
-	it->kaddr = kmap_atomic(it->page);
+	it->page = erofs_get_inline_page(inode, it->blkaddr);
+	if (IS_ERR(it->page))
+		return PTR_ERR(it->page);
 
+	it->kaddr = kmap_atomic(it->page);
 	return vi->xattr_isize - xattr_header_sz;
 }
 
 static int xattr_foreach(struct xattr_iter *it,
-	struct xattr_iter_handlers *op, unsigned *tlimit)
+	const struct xattr_iter_handlers *op, unsigned *tlimit)
 {
 	struct erofs_xattr_entry entry;
 	unsigned value_sz, processed, slice;
 	int err;
 
 	/* 0. fixup blkaddr, ofs, ipage */
-	xattr_iter_fixup(it);
+	err = xattr_iter_fixup(it);
+	if (unlikely(err))
+		return err;
 
 	/*
 	 * 1. read xattr entry to the memory,

@@ -181,7 +204,9 @@ static int xattr_foreach(struct xattr_iter *it,
 		if (it->ofs >= EROFS_BLKSIZ) {
 			BUG_ON(it->ofs > EROFS_BLKSIZ);
 
-			xattr_iter_fixup(it);
+			err = xattr_iter_fixup(it);
+			if (unlikely(err))
+				goto out;
 			it->ofs = 0;
 		}
 

@@ -213,7 +238,10 @@ static int xattr_foreach(struct xattr_iter *it,
 	while (processed < value_sz) {
 		if (it->ofs >= EROFS_BLKSIZ) {
 			BUG_ON(it->ofs > EROFS_BLKSIZ);
-			xattr_iter_fixup(it);
+
+			err = xattr_iter_fixup(it);
+			if (unlikely(err))
+				goto out;
 			it->ofs = 0;
 		}
 

@@ -273,7 +301,7 @@ static void xattr_copyvalue(struct xattr_iter *_it,
 	memcpy(it->buffer + processed, buf, len);
 }
 
-static struct xattr_iter_handlers find_xattr_handlers = {
+static const struct xattr_iter_handlers find_xattr_handlers = {
 	.entry = xattr_entrymatch,
 	.name = xattr_namematch,
 	.alloc_buffer = xattr_checkbuffer,

drivers/staging/erofs/xattr.c +13 -6

+			break;
 	}
-	xattr_iter_end(&it->it, true);
+	xattr_iter_end_final(&it->it);
 
 	return ret < 0 ? ret : it->buffer_size;
 }

@@ -318,9 +349,10 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
 			if (i)
 				xattr_iter_end(&it->it, true);
 
-			it->it.page = erofs_get_meta_page_nofail(sb,
-				blkaddr, false);
-			BUG_ON(IS_ERR(it->it.page));
+			it->it.page = erofs_get_meta_page(sb, blkaddr, false);
+			if (IS_ERR(it->it.page))
+				return PTR_ERR(it->it.page);
+
 			it->it.kaddr = kmap_atomic(it->it.page);
 			it->it.blkaddr = blkaddr;
 		}

@@ -328,9 +360,12 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
 		ret = xattr_foreach(&it->it, &find_xattr_handlers, NULL);
 		if (ret >= 0)
 			break;
+
+		if (unlikely(ret != -ENOATTR))	/* -ENOMEM, -EIO, etc. */
+			break;
 	}
 	if (vi->xattr_shared_count)
-		xattr_iter_end(&it->it, true);
+		xattr_iter_end_final(&it->it);
 
 	return ret < 0 ? ret : it->buffer_size;
 }

@@ -355,7 +390,9 @@ int erofs_getxattr(struct inode *inode, int index,
 	if (unlikely(name == NULL))
 		return -EINVAL;
 
-	init_inode_xattrs(inode);
+	ret = init_inode_xattrs(inode);
+	if (unlikely(ret < 0))
+		return ret;
 
 	it.index = index;
 

Quoted 14 lines

drivers/staging/erofs/xattr.c +4 -7

-static void xattr_iter_fixup(struct xattr_iter *it)
+static inline int xattr_iter_fixup(struct xattr_iter *it)
 {
-	if (unlikely(it->ofs >= EROFS_BLKSIZ)) {
-		xattr_iter_end(it, true);
+	if (likely(it->ofs < EROFS_BLKSIZ))
+		return 0;
 
-		it->blkaddr += erofs_blknr(it->ofs);
-		it->page = erofs_get_meta_page_nofail(it->sb,
-			it->blkaddr, false);
-		BUG_ON(IS_ERR(it->page));
+	xattr_iter_end(it, true);

drivers/staging/erofs/xattr.c struct xattr_iter_handlers { · line 131

Quoted 8 lines

drivers/staging/erofs/xattr.c +6 -2

-		it->kaddr = kmap_atomic(it->page);
-		it->ofs = erofs_blkoff(it->ofs);
+	it->blkaddr += erofs_blknr(it->ofs);
+
+	it->page = erofs_get_meta_page(it->sb, it->blkaddr, false);
+	if (IS_ERR(it->page)) {
+		it->page = NULL;
+		return PTR_ERR(it->page);

This is returning PTR_ERR(NULL) which is success. There is a smatch test for this and maybe other static checkers as well so it would have been caught very quickly.

Quoted 72 lines

drivers/staging/erofs/xattr.c +20 -8

 	}
+
+	it->kaddr = kmap_atomic(it->page);
+	it->ofs = erofs_blkoff(it->ofs);
+	return 0;
 }
 
 static int inline_xattr_iter_begin(struct xattr_iter *it,

@@ -134,22 +154,25 @@ static int inline_xattr_iter_begin(struct xattr_iter *it,
 	it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs);
 	it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs);
 
-	it->page = erofs_get_inline_page_nofail(inode, it->blkaddr);
-	BUG_ON(IS_ERR(it->page));
-	it->kaddr = kmap_atomic(it->page);
+	it->page = erofs_get_inline_page(inode, it->blkaddr);
+	if (IS_ERR(it->page))
+		return PTR_ERR(it->page);
 
+	it->kaddr = kmap_atomic(it->page);
 	return vi->xattr_isize - xattr_header_sz;
 }
 
 static int xattr_foreach(struct xattr_iter *it,
-	struct xattr_iter_handlers *op, unsigned *tlimit)
+	const struct xattr_iter_handlers *op, unsigned *tlimit)
 {
 	struct erofs_xattr_entry entry;
 	unsigned value_sz, processed, slice;
 	int err;
 
 	/* 0. fixup blkaddr, ofs, ipage */
-	xattr_iter_fixup(it);
+	err = xattr_iter_fixup(it);
+	if (unlikely(err))
+		return err;
 
 	/*
 	 * 1. read xattr entry to the memory,

@@ -181,7 +204,9 @@ static int xattr_foreach(struct xattr_iter *it,
 		if (it->ofs >= EROFS_BLKSIZ) {
 			BUG_ON(it->ofs > EROFS_BLKSIZ);
 
-			xattr_iter_fixup(it);
+			err = xattr_iter_fixup(it);
+			if (unlikely(err))
+				goto out;
 			it->ofs = 0;
 		}
 

@@ -213,7 +238,10 @@ static int xattr_foreach(struct xattr_iter *it,
 	while (processed < value_sz) {
 		if (it->ofs >= EROFS_BLKSIZ) {
 			BUG_ON(it->ofs > EROFS_BLKSIZ);
-			xattr_iter_fixup(it);
+
+			err = xattr_iter_fixup(it);
+			if (unlikely(err))
+				goto out;
 			it->ofs = 0;
 		}
 

@@ -273,7 +301,7 @@ static void xattr_copyvalue(struct xattr_iter *_it,
 	memcpy(it->buffer + processed, buf, len);
 }
 
-static struct xattr_iter_handlers find_xattr_handlers = {
+static const struct xattr_iter_handlers find_xattr_handlers = {
 	.entry = xattr_entrymatch,
 	.name = xattr_namematch,
 	.alloc_buffer = xattr_checkbuffer,

drivers/staging/erofs/xattr.c static int inline_getxattr(struct inode *inode, struct getxattr_iter *it) · line 326

Quoted 5 lines

drivers/staging/erofs/xattr.c +2 -0

@@ -294,8 +322,11 @@ static int inline_getxattr(struct inode *inode, struct getxattr_iter *it)
 		ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining);
 		if (ret >= 0)
 			break;
+
+		if (unlikely(ret != -ENOATTR))	/* -ENOMEM, -EIO, etc. */

I have held off commenting on all the likely/unlikely annotations we are adding because I don't know what the fast paths are in this code. However, this is clearly an error path here, not on a fast path.

Generally the rule on likely/unlikely is that they hurt readability so we should only add them if it makes a difference in benchmarking.

Quoted 44 lines

drivers/staging/erofs/xattr.c +13 -6

+			break;
 	}
-	xattr_iter_end(&it->it, true);
+	xattr_iter_end_final(&it->it);
 
 	return ret < 0 ? ret : it->buffer_size;
 }

@@ -318,9 +349,10 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
 			if (i)
 				xattr_iter_end(&it->it, true);
 
-			it->it.page = erofs_get_meta_page_nofail(sb,
-				blkaddr, false);
-			BUG_ON(IS_ERR(it->it.page));
+			it->it.page = erofs_get_meta_page(sb, blkaddr, false);
+			if (IS_ERR(it->it.page))
+				return PTR_ERR(it->it.page);
+
 			it->it.kaddr = kmap_atomic(it->it.page);
 			it->it.blkaddr = blkaddr;
 		}

@@ -328,9 +360,12 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
 		ret = xattr_foreach(&it->it, &find_xattr_handlers, NULL);
 		if (ret >= 0)
 			break;
+
+		if (unlikely(ret != -ENOATTR))	/* -ENOMEM, -EIO, etc. */
+			break;
 	}
 	if (vi->xattr_shared_count)
-		xattr_iter_end(&it->it, true);
+		xattr_iter_end_final(&it->it);
 
 	return ret < 0 ? ret : it->buffer_size;
 }

@@ -355,7 +390,9 @@ int erofs_getxattr(struct inode *inode, int index,
 	if (unlikely(name == NULL))
 		return -EINVAL;
 
-	init_inode_xattrs(inode);
+	ret = init_inode_xattrs(inode);
+	if (unlikely(ret < 0))
+		return ret;
 

drivers/staging/erofs/xattr.c static int xattr_skipvalue(struct xattr_iter *_it, · line 535

Quoted 4 lines

drivers/staging/erofs/xattr.c +0 -0

 	it.index = index;
 

@@ -498,7 +535,7 @@ static int xattr_skipvalue(struct xattr_iter *_it,
 	return 1;

Not related to your patch but what does "return 1;" mean here? It's weird to me that xattr_skipvalue() doesn't use value_sz at all. I can't decide if the function always succeeds or always fails.

The xattr_skipvalue/alloc_buffer function is called like this:

	err = op->alloc_buffer(it, value_sz);
	if (err) {
		it->ofs += value_sz;
		goto out;
	}

It looks like if we hit an error, we increase it->ofs. All the other error paths in this function take a negative error and increase it->ofs so this looks like an error path. The goto out look like this:

	/* we assume that ofs is aligned with 4 bytes */
	it->ofs = EROFS_XATTR_ALIGN(it->ofs);
	return err;

So we return 1 here and the callers all treat it at success... There needs to be some documentation for what positive returns mean.

regards,
dan carpenter

Quoted 4 lines

	/* we assume that ofs is aligned with 4 bytes */
	it->ofs = EROFS_XATTR_ALIGN(it->ofs);
	return err;

Quoted 4 lines · Gao Xiang

Quoted 4 lines

	/* we assume that ofs is aligned with 4 bytes */
	it->ofs = EROFS_XATTR_ALIGN(it->ofs);
	return err;

This might be cleaner if we wrote:

	return (err < 0) ? error : 0;

The callers all treate zero and one the same so there isn't any reason to propogate the 1 back.

regards,
dan carpenter

But it is better to fix them in an independent patch. :)

Quoted 11 lines

drivers/staging/erofs/xattr.c static int inline_getxattr(struct inode *inode, struct getxattr_iter *it) · line 326

Quoted 6 lines

drivers/staging/erofs/xattr.c +2 -0

@@ -294,8 +322,11 @@ static int inline_getxattr(struct inode *inode, struct getxattr_iter *it)
 		ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining);
 		if (ret >= 0)
 			break;
+
+		if (unlikely(ret != -ENOATTR))	/* -ENOMEM, -EIO, etc. */

I have held off commenting on all the likely/unlikely annotations we are adding because I don't know what the fast paths are in this code. However, this is clearly an error path here, not on a fast path.

Quoted 3 lines

Generally the rule on likely/unlikely is that they hurt readability so we should only add them if it makes a difference in benchmarking.

In my opinion, return values other than 0 and ENOATTR(ENODATA) rarely happens, it should be in the slow path...

Quoted 13 lines · Gao Xiang

Quoted 13 lines

drivers/staging/erofs/xattr.c static int inline_getxattr(struct inode *inode, struct getxattr_iter *it) · line 326

Quoted 6 lines

drivers/staging/erofs/xattr.c +2 -0

@@ -294,8 +322,11 @@ static int inline_getxattr(struct inode *inode, struct getxattr_iter *it)
 		ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining);
 		if (ret >= 0)
 			break;
+
+		if (unlikely(ret != -ENOATTR))	/* -ENOMEM, -EIO, etc. */

I have held off commenting on all the likely/unlikely annotations we are adding because I don't know what the fast paths are in this code. However, this is clearly an error path here, not on a fast path.

Generally the rule on likely/unlikely is that they hurt readability so we should only add them if it makes a difference in benchmarking.

Quoted 3 lines

In my opinion, return values other than 0 and ENOATTR(ENODATA) rarely happens, it should be in the slow path...

What I'm trying to say is please stop adding so many likely/unlikely annotations. You should only add them if you have the benchmark data to show the it really is required.

regards,
dan carpenter

Quoted 3 lines

Generally the rule on likely/unlikely is that they hurt readability so we should only add them if it makes a difference in benchmarking.

In my opinion, return values other than 0 and ENOATTR(ENODATA) rarely happens, it should be in the slow path...

From: Gao Xiang <gaoxiang25 at huawei.com>

This patch introduces 'struct z_erofs_vle_work_finder' to clean up arguments of z_erofs_vle_work_lookup and z_erofs_vle_work_register.

Signed-off-by Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by Chao Yu <yuchao0 at huawei.com>

Signed-off-by Chao Yu <yuchao0 at huawei.com>

---
 drivers/staging/erofs/unzip_vle.c | 89 ++++++++++++++++---------------
 1 file changed, 47 insertions(+), 42 deletions(-)

drivers/staging/erofs/unzip_vle.c +12 -6

index b2e05e2b4116..5032b3b05de1 100644
@@ -271,36 +271,42 @@ static inline bool try_to_claim_workgroup(
 	return true;	/* lucky, I am the followee :) */
 }
 
+struct z_erofs_vle_work_finder {
+	struct super_block *sb;
+	pgoff_t idx;
+	unsigned pageofs;
+
+	struct z_erofs_vle_workgroup **grp_ret;
+	enum z_erofs_vle_work_role *role;
+	z_erofs_vle_owned_workgrp_t *owned_head;
+	bool *hosted;
+};
+
 static struct z_erofs_vle_work *
-z_erofs_vle_work_lookup(struct super_block *sb,
-			pgoff_t idx, unsigned pageofs,
-			struct z_erofs_vle_workgroup **grp_ret,
-			enum z_erofs_vle_work_role *role,
-			z_erofs_vle_owned_workgrp_t *owned_head,
-			bool *hosted)
+z_erofs_vle_work_lookup(const struct z_erofs_vle_work_finder *f)
 {

Quoted 40 lines · Chao Yu

From: Gao Xiang <gaoxiang25 at huawei.com>

This patch introduces 'struct z_erofs_vle_work_finder' to clean up arguments of z_erofs_vle_work_lookup and z_erofs_vle_work_register.

Signed-off-by Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by Chao Yu <yuchao0 at huawei.com>

Signed-off-by Chao Yu <yuchao0 at huawei.com>

---
 drivers/staging/erofs/unzip_vle.c | 89 ++++++++++++++++---------------
 1 file changed, 47 insertions(+), 42 deletions(-)

drivers/staging/erofs/unzip_vle.c +12 -6

index b2e05e2b4116..5032b3b05de1 100644
@@ -271,36 +271,42 @@ static inline bool try_to_claim_workgroup(
 	return true;	/* lucky, I am the followee :) */
 }
 
+struct z_erofs_vle_work_finder {
+	struct super_block *sb;
+	pgoff_t idx;
+	unsigned pageofs;
+
+	struct z_erofs_vle_workgroup **grp_ret;
+	enum z_erofs_vle_work_role *role;
+	z_erofs_vle_owned_workgrp_t *owned_head;
+	bool *hosted;
+};
+
 static struct z_erofs_vle_work *
-z_erofs_vle_work_lookup(struct super_block *sb,
-			pgoff_t idx, unsigned pageofs,
-			struct z_erofs_vle_workgroup **grp_ret,
-			enum z_erofs_vle_work_role *role,
-			z_erofs_vle_owned_workgrp_t *owned_head,
-			bool *hosted)
+z_erofs_vle_work_lookup(const struct z_erofs_vle_work_finder *f)
 {

drivers/staging/erofs/unzip_vle.c static inline bool try_to_claim_workgroup( · line 295

Quoted 10 lines

drivers/staging/erofs/unzip_vle.c +2 -2

 	bool tag, primary;
 	struct erofs_workgroup *egrp;
 	struct z_erofs_vle_workgroup *grp;
 	struct z_erofs_vle_work *work;
 
-	egrp = erofs_find_workgroup(sb, idx, &tag);
+	egrp = erofs_find_workgroup(f->sb, f->idx, &tag);
 	if (egrp == NULL) {
-		*grp_ret = NULL;
+		*f->grp_ret = NULL;

All these pointers to pointer seem a bit messy. Just do this:

	struct z_erofs_vle_workgroup *grp;

Then replace "grp" in z_erofs_vle_work_iter_begin() with finder.grp;

regards,
dan carpenter

Yeah. You'd have to remove the const.

Anyway, on looking at it more, I guess this patch is fine for now. We will probably end up changing z_erofs_vle_work_lookup() and z_erofs_vle_work_register() some more in the future.

regards,
dan carpenter

drivers/staging/erofs/unzip_vle.c const struct address_space_operations z_erofs_vle_normalaccess_aops = { · line 1423

Quoted 5 lines

drivers/staging/erofs/unzip_vle.c +2 -3

-static inline unsigned
-vle_compressed_index_clusterofs(unsigned clustersize,
-	struct z_erofs_vle_decompressed_index *di)
+static inline int
+vle_decompressed_index_clusterofs(unsigned int *clusterofs,

Not related to your patch, but don't make functions inline. Leave it to the compiler to decide.

regards,
dan carpenter