Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[deliverable/linux.git] / fs / cifs / connect.c

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 78db68a5cf44c83ddc8f60cfa89e4796d8fa0ffc..94b7788c3189281e043ecf82b9bf4fb1e9d0e0f7 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1653,24 +1653,26 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
                         * If yes, we have encountered a double deliminator
                         * reset the NULL character to the deliminator
                         */
-                       if (tmp_end < end && tmp_end[1] == delim)
+                       if (tmp_end < end && tmp_end[1] == delim) {
                                tmp_end[0] = delim;
 
-                       /* Keep iterating until we get to a single deliminator
-                        * OR the end
-                        */
-                       while ((tmp_end = strchr(tmp_end, delim)) != NULL &&
-                              (tmp_end[1] == delim)) {
-                               tmp_end = (char *) &tmp_end[2];
-                       }
+                               /* Keep iterating until we get to a single
+                                * deliminator OR the end
+                                */
+                               while ((tmp_end = strchr(tmp_end, delim))
+                                       != NULL && (tmp_end[1] == delim)) {
+                                               tmp_end = (char *) &tmp_end[2];
+                               }
 
-                       /* Reset var options to point to next element */
-                       if (tmp_end) {
-                               tmp_end[0] = '\0';
-                               options = (char *) &tmp_end[1];
-                       } else
-                               /* Reached the end of the mount option string */
-                               options = end;
+                               /* Reset var options to point to next element */
+                               if (tmp_end) {
+                                       tmp_end[0] = '\0';
+                                       options = (char *) &tmp_end[1];
+                               } else
+                                       /* Reached the end of the mount option
+                                        * string */
+                                       options = end;
+                       }
 
                        /* Now build new password string */
                        temp_len = strlen(value);
@@ -3443,6 +3445,18 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
 #define CIFS_DEFAULT_NON_POSIX_RSIZE (60 * 1024)
 #define CIFS_DEFAULT_NON_POSIX_WSIZE (65536)
 
+/*
+ * On hosts with high memory, we can't currently support wsize/rsize that are
+ * larger than we can kmap at once. Cap the rsize/wsize at
+ * LAST_PKMAP * PAGE_SIZE. We'll never be able to fill a read or write request
+ * larger than that anyway.
+ */
+#ifdef CONFIG_HIGHMEM
+#define CIFS_KMAP_SIZE_LIMIT   (LAST_PKMAP * PAGE_CACHE_SIZE)
+#else /* CONFIG_HIGHMEM */
+#define CIFS_KMAP_SIZE_LIMIT   (1<<24)
+#endif /* CONFIG_HIGHMEM */
+
 static unsigned int
 cifs_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
 {
@@ -3473,6 +3487,9 @@ cifs_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
                wsize = min_t(unsigned int, wsize,
                                server->maxBuf - sizeof(WRITE_REQ) + 4);
 
+       /* limit to the amount that we can kmap at once */
+       wsize = min_t(unsigned int, wsize, CIFS_KMAP_SIZE_LIMIT);
+
        /* hard limit of CIFS_MAX_WSIZE */
        wsize = min_t(unsigned int, wsize, CIFS_MAX_WSIZE);
 
@@ -3493,18 +3510,15 @@ cifs_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
         * MS-CIFS indicates that servers are only limited by the client's
         * bufsize for reads, testing against win98se shows that it throws
         * INVALID_PARAMETER errors if you try to request too large a read.
+        * OS/2 just sends back short reads.
         *
-        * If the server advertises a MaxBufferSize of less than one page,
-        * assume that it also can't satisfy reads larger than that either.
-        *
-        * FIXME: Is there a better heuristic for this?
+        * If the server doesn't advertise CAP_LARGE_READ_X, then assume that
+        * it can't handle a read request larger than its MaxBufferSize either.
         */
        if (tcon->unix_ext && (unix_cap & CIFS_UNIX_LARGE_READ_CAP))
                defsize = CIFS_DEFAULT_IOSIZE;
        else if (server->capabilities & CAP_LARGE_READ_X)
                defsize = CIFS_DEFAULT_NON_POSIX_RSIZE;
-       else if (server->maxBuf >= PAGE_CACHE_SIZE)
-               defsize = CIFSMaxBufSize;
        else
                defsize = server->maxBuf - sizeof(READ_RSP);
 
@@ -3517,6 +3531,9 @@ cifs_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *pvolume_info)
        if (!(server->capabilities & CAP_LARGE_READ_X))
                rsize = min_t(unsigned int, CIFSMaxBufSize, rsize);
 
+       /* limit to the amount that we can kmap at once */
+       rsize = min_t(unsigned int, rsize, CIFS_KMAP_SIZE_LIMIT);
+
        /* hard limit of CIFS_MAX_RSIZE */
        rsize = min_t(unsigned int, rsize, CIFS_MAX_RSIZE);