handle partial reads/writes

dump_inode.c

@@ -25,6 +25,7 @@
 #include <ufs/ufs/dir.h>
 
 #include <err.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <inttypes.h>
 #include <stdio.h>
@@ -430,31 +431,45 @@ void *xmalloc(size_t size) {
 }
 
 void xpread(int fd, void *buf, size_t nbytes, off_t offset) {
-  ssize_t n = pread(fd, buf, nbytes, offset);
-  if (n == -1) {
-    err(1, "pread() failed");
-  }
-  if (n != nbytes) {
-    errx(1, "Incomplete read");
+  while (nbytes) {
+    ssize_t n = pread(fd, buf, nbytes, offset);
+    if (n == -1) {
+      if (errno == EINTR) {
+        continue;
+      }
+      err(1, "pread() failed");
+    }
+    buf = (char *)buf + n;
+    nbytes -= n;
+    offset += n;
   }
 }
 
 void xwrite(int fd, void *buf, size_t nbytes) {
-  ssize_t n = write(fd, buf, nbytes);
-  if (n == -1) {
-    err(1, "write() failed");
-  }
-  if (n != nbytes) {
-    errx(1, "Incomplete write");
+  while (nbytes) {
+    ssize_t n = write(fd, buf, nbytes);
+    if (n == -1) {
+      if (errno == EINTR || errno == EAGAIN) {
+        continue;
+      }
+      err(1, "write() failed");
+    }
+    buf = (char *)buf + n;
+    nbytes -= n;
   }
 }
 
 void xpwrite(int fd, void *buf, size_t nbytes, off_t offset) {
-  ssize_t n = pwrite(fd, buf, nbytes, offset);
-  if (n == -1) {
-    err(1, "pwrite() failed");
-  }
-  if (n != nbytes) {
-    errx(1, "Incomplete write");
+  while (nbytes) {
+    ssize_t n = pwrite(fd, buf, nbytes, offset);
+    if (n == -1) {
+      if (errno == EINTR) {
+        continue;
+      }
+      err(1, "pwrite() failed");
+    }
+    buf = (char *)buf + n;
+    nbytes -= n;
+    offset += n;
   }
 }