Changeset 77628 in vbox

Timestamp:

Mar 9, 2019 6:12:49 PM (6 years ago)

Author:

vboxsync

Message:

linux/vboxsf: Slash the right page0 offset in vbsf_iter_lock_pages(). Corrected IOVEC detection in vbsf_iter_max_span_of_pages(). More logging. bugref:9172 ticketref:17360

Location:

trunk/src/VBox/Additions/linux/sharedfolders

Files:

• regops.c (modified) (11 diffs)
• vfsmod.h (modified) (2 diffs)

trunk/src/VBox/Additions/linux/sharedfolders/regops.c

@@ -1131 +1131 @@
     int    rc       = 0;
 
-    Assert(iov_iter_count(iter) > 0);
+    Assert(iov_iter_count(iter) + pStash->cb > 0);
     if (!(iter->type & ITER_KVEC)) {
         /*
@@ -1149 +1149 @@
                 *pcbChunk  = cbChunk;
                 *pcPages   = cPages;
+                SFLOGFLOW(("vbsf_iter_lock_pages: returns %d - cPages=%#zx offPage0=%#zx cbChunk=%zx (stashed)\n",
+                           rc, cPages, offPage0, cbChunk));
                 return 0;
             }
             cMaxPages -= 1;
+            SFLOG3(("vbsf_iter_lock_pages: Picked up stashed page: %#zx LB %#zx\n", offPage0, cbChunk));
         } else {
 # if LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 0)
@@ -1178 +1181 @@
                     cPages     = RT_ALIGN_Z(offPage0 + cbSegRet, PAGE_SIZE) >> PAGE_SHIFT;
                     cMaxPages -= cPages;
+                    SFLOG3(("vbsf_iter_lock_pages: iov_iter_get_pages -> %#zx @ %#zx; %#zx pages [first]\n", cbSegRet, offPage0, cPages));
                     if (   cMaxPages == 0
                         || ((offPage0 + (size_t)cbSegRet) & PAGE_OFFSET_MASK))
@@ -1200 +1204 @@
                 if (cbSegRet > 0) {
                     iov_iter_advance(iter, cbSegRet); /** @todo maybe not do this if we stash the page? */
-                    Assert(cbSegRet <= PAGE_SIZE);
+                    Assert(offPgProbe + cbSegRet <= PAGE_SIZE);
                     if (offPgProbe == 0) {
                         cbChunk   += cbSegRet;
                         cPages    += 1;
                         cMaxPages -= 1;
+                        SFLOG3(("vbsf_iter_lock_pages: iov_iter_get_pages(1) -> %#zx @ %#zx\n", cbSegRet, offPgProbe));
                         if (   cMaxPages == 0
                             || cbSegRet != PAGE_SIZE)
@@ -1216 +1221 @@
                             cbSegRet = iov_iter_get_pages(iter, &papPages[cPages], iov_iter_count(iter), cMaxPages, &offPgProbe);
                             if (cbSegRet > 0) {
-                                size_t const cSegsRet = RT_ALIGN_Z((size_t)cbSegRet, PAGE_SIZE) >> PAGE_SHIFT;
+                                size_t const cPgRet = RT_ALIGN_Z((size_t)cbSegRet, PAGE_SIZE) >> PAGE_SHIFT;
                                 Assert(offPgProbe == 0);
                                 iov_iter_advance(iter, cbSegRet);
-                                cPages    += cSegsRet;
-                                cMaxPages -= cSegsRet;
+                                SFLOG3(("vbsf_iter_lock_pages: iov_iter_get_pages() -> %#zx; %#zx pages\n", cbSegRet, cPgRet));
+                                cPages    += cPgRet;
+                                cMaxPages -= cPgRet;
                                 cbChunk   += cbSegRet;
                                 if (   cMaxPages == 0
@@ -1234 +1240 @@
                         /* The segment didn't start at a page boundrary, so stash it for
                            the next round: */
+                        SFLOGFLOW(("vbsf_iter_lock_pages: iov_iter_get_pages(1) -> %#zx @ %#zx; stashed\n", cbSegRet, offPgProbe));
                         Assert(papPages[cPages]);
                         pStash->pPage = papPages[cPages];
-                        pStash->off   = offPage0;
+                        pStash->off   = offPgProbe;
                         pStash->cb    = cbSegRet;
                         break;
@@ -1316 +1323 @@
     *pcbChunk  = cbChunk;
     *pcPages   = cPages;
+    SFLOGFLOW(("vbsf_iter_lock_pages: returns %d - cPages=%#zx offPage0=%#zx cbChunk=%zx\n", rc, cPages, offPage0, cbChunk));
     return rc;
 }
@@ -1366 +1374 @@
 {
     size_t cPages;
-    if (iter->type & (ITER_IOVEC | ITER_KVEC)) {
+    if (iter_is_iovec(iter) || (iter->type & ITER_KVEC)) {
         const struct iovec *pCurIov    = iter->iov;
         size_t              cLeft      = iter->nr_segs;
         size_t              cPagesSpan = 0;
 
+        /* iovect and kvec are identical, except for the __user tagging of iov_base. */
         AssertCompileMembersSameSizeAndOffset(struct iovec, iov_base, struct kvec, iov_base);
         AssertCompileMembersSameSizeAndOffset(struct iovec, iov_len,  struct kvec, iov_len);
@@ -1387 +1396 @@
                     cPagesSpan = 0;
             }
+            SFLOGFLOW(("vbsf_iter: seg[0]= %p LB %#zx\n", pCurIov->iov_base, pCurIov->iov_len));
             pCurIov++;
             cLeft--;
@@ -1417 +1427 @@
                 }
             }
+            SFLOGFLOW(("vbsf_iter: seg[%u]= %p LB %#zx\n", iter->nr_segs - cLeft, pCurIov->iov_base, pCurIov->iov_len));
             pCurIov++;
         }
@@ -1427 +1438 @@
         cPages = (iov_iter_count(iter) + (PAGE_SIZE * 2 - 2) * cSegs) >> PAGE_SHIFT;
     }
+    SFLOGFLOW(("vbsf_iter_max_span_of_pages: returns %#zx\n", cPages));
     return cPages;
 }

trunk/src/VBox/Additions/linux/sharedfolders/vfsmod.h

@@ -396 +396 @@
 # define TRACE()          LogFunc(("tracepoint\n"))
 # define SFLOGFLOW(aArgs) Log(aArgs)
+# define SFLOG2(aArgs)    Log2(aArgs)
+# define SFLOG3(aArgs)    Log3(aArgs)
 # ifdef LOG_ENABLED
 #  define SFLOG_ENABLED   1
@@ -402 +404 @@
 # define TRACE()          RTLogBackdoorPrintf("%s: tracepoint\n", __FUNCTION__)
 # define SFLOGFLOW(aArgs) RTLogBackdoorPrintf aArgs
+# define SFLOG2(aArgs)    RTLogBackdoorPrintf aArgs
+# define SFLOG3(aArgs)    RTLogBackdoorPrintf aArgs
 # define SFLOG_ENABLED    1
 #endif