[CRIU] [PATCH 2/2] page-read: rewrite some code to use it in deduplication

[Tikhomirov Pavel]

Signed-off-by: Tikhomirov Pavel <snorcht at gmail.com>
---
 include/page-read.h |    2 ++
 page-read.c         |   12 +++++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/include/page-read.h b/include/page-read.h
index b19ea69..cbae2a0 100644
--- a/include/page-read.h
+++ b/include/page-read.h
@@ -66,4 +66,6 @@ struct page_read {
 };
 
 int open_page_read(int pid, struct page_read *);
+inline void pagemap2iovec(PagemapEntry *pe, struct iovec *iov);
+int seek_pagemap_page(struct page_read *pr, unsigned long vaddr);
 #endif
diff --git a/page-read.c b/page-read.c
index a3ea7ac..6f3541c 100644
--- a/page-read.c
+++ b/page-read.c
@@ -36,7 +36,7 @@ static int read_page(struct page_read *pr, unsigned long vaddr, void *buf)
 	return 1;
 }
 
-static inline void pagemap2iovec(PagemapEntry *pe, struct iovec *iov)
+inline void pagemap2iovec(PagemapEntry *pe, struct iovec *iov)
 {
 	iov->iov_base = decode_pointer(pe->vaddr);
 	iov->iov_len = pe->nr_pages * PAGE_SIZE;
@@ -82,7 +82,7 @@ static void skip_pagemap_pages(struct page_read *pr, unsigned long len)
 	pr->cvaddr += len;
 }
 
-static int seek_pagemap_page(struct page_read *pr, unsigned long vaddr)
+int seek_pagemap_page(struct page_read *pr, unsigned long vaddr)
 {
 	int ret;
 	struct iovec iov;
@@ -95,7 +95,11 @@ static int seek_pagemap_page(struct page_read *pr, unsigned long vaddr)
 	while (1) {
 		unsigned long iov_end;
 
-		BUG_ON(vaddr < pr->cvaddr);
+		if (vaddr < pr->cvaddr) {
+			pr_err("Missing %lu in parent pagemap, iov: base=%lu,len=%lu",
+			       vaddr, (unsigned long)iov.iov_base, iov.iov_len);
+			return -1;
+		}
 		iov_end = (unsigned long)iov.iov_base + iov.iov_len;
 
 		if (iov_end <= vaddr) {
@@ -124,6 +128,8 @@ static int read_pagemap_page(struct page_read *pr, unsigned long vaddr, void *bu
 		if (ret == -1)
 			return ret;
 		ret = read_pagemap_page(pr->parent, vaddr, buf);
+		if (ret < 0)
+			return ret;
 	} else {
 		pr_debug("\tpr%u Read page %lx from self %lx/%"PRIx64"\n", pr->id,
 				vaddr, pr->cvaddr, lseek(pr->fd_pg, 0, SEEK_CUR));
-- 
1.7.9.5