linux file interface fixes

[palacios.git] / linux_module / iface-file.c

diff --git a/linux_module/iface-file.c b/linux_module/iface-file.c
index 965023a..5489764 100644 (file)
--- a/linux_module/iface-file.c
+++ b/linux_module/iface-file.c
@@ -4,6 +4,8 @@
 
 
 #include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/version.h>
 #include <linux/file.h>
 #include <linux/spinlock.h>
 #include <linux/uaccess.h>
@@ -16,6 +18,7 @@
 
 static struct list_head global_files;
 
+#define isprint(a) ((a >= ' ') && (a <= '~'))
 
 struct palacios_file {
     struct file * filp;
@@ -39,6 +42,138 @@ struct vm_file_state {
 
 
 
+static int palacios_file_mkdir(const char * pathname, unsigned short perms, int recurse);
+
+static int mkdir_recursive(const char * path, unsigned short perms) {
+    char * tmp_str = NULL;
+    char * dirname_ptr;
+    char * tmp_iter;
+
+    tmp_str = kmalloc(strlen(path) + 1, GFP_KERNEL);
+    memset(tmp_str, 0, strlen(path) + 1);
+    strncpy(tmp_str, path, strlen(path));
+
+    dirname_ptr = tmp_str;
+    tmp_iter = tmp_str;
+
+    // parse path string, call palacios_file_mkdir recursively.
+
+
+    while (dirname_ptr != NULL) {
+       int done = 0;
+
+       while ((*tmp_iter != '/') && 
+              (*tmp_iter != '\0')) {
+
+           if ( (!isprint(*tmp_iter))) {
+               printk("Invalid character in path name (%d)\n", *tmp_iter);
+               return -1;
+           } else {
+               tmp_iter++;
+           }
+       }
+
+       if (*tmp_iter == '/') {
+           *tmp_iter = '\0';
+       } else {
+           done = 1;
+       }
+
+       // Ignore empty directories
+       if ((tmp_iter - dirname_ptr) > 1) {
+           if (palacios_file_mkdir(tmp_str, perms, 0) != 0) {
+               printk("Could not create directory (%s)\n", tmp_str);
+               return -1;
+           }
+       }
+
+       if (done) {
+           break;
+       } else {
+           *tmp_iter = '/';
+       }
+       
+       tmp_iter++;
+
+       dirname_ptr = tmp_iter;
+    }
+    
+    kfree(tmp_str);
+
+    return 0;
+}
+
+static int palacios_file_mkdir(const char * pathname, unsigned short perms, int recurse) {
+    /* Welcome to the jungle... */
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,1,0)
+    /* DO NOT REFERENCE THIS VARIABLE */
+    /* It only exists to provide version compatibility */
+    struct path tmp_path; 
+#endif
+
+    struct path * path_ptr = NULL;
+    struct dentry * dentry;
+    int ret = 0;
+
+
+
+    if (recurse != 0) {
+       return mkdir_recursive(pathname, perms);
+    } 
+
+    /* Before Linux 3.1 this was somewhat more difficult */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,1,0)
+    {
+       struct nameidata nd;
+
+       // I'm not 100% sure about the version here, but it was around this time that the API changed
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,35) 
+       ret = kern_path_parent(pathname, &nd);
+#else 
+
+       if (path_lookup(pathname, LOOKUP_DIRECTORY | LOOKUP_FOLLOW, &nd) == 0) {
+           return 0;
+       }
+
+       if (path_lookup(pathname, LOOKUP_PARENT | LOOKUP_FOLLOW, &nd) != 0) {
+           return -1;
+       }
+#endif
+
+       if (ret != 0) {
+           printk("%s:%d - Error: kern_path_parent() returned error for (%s)\n", __FILE__, __LINE__, 
+                  pathname);
+           return -1;
+       }
+       
+       dentry = lookup_create(&nd, 1);
+       path_ptr = &(nd.path);
+    }
+#else 
+    {
+       dentry = kern_path_create(AT_FDCWD, pathname, &tmp_path, 1);
+       
+       if (IS_ERR(dentry)) {
+           return 0;
+       }
+       
+       path_ptr = &tmp_path;
+    }
+#endif    
+
+
+    if (!IS_ERR(dentry)) {
+       ret = vfs_mkdir(path_ptr->dentry->d_inode, dentry, perms);
+    }
+
+    mutex_unlock(&(path_ptr->dentry->d_inode->i_mutex));
+    path_put(path_ptr);
+
+    return ret;
+}
+
+
 static void * palacios_file_open(const char * path, int mode, void * private_data) {
     struct v3_guest * guest = (struct v3_guest *)private_data;
     struct palacios_file * pfile = NULL;       
@@ -69,9 +204,12 @@ static void * palacios_file_open(const char * path, int mode, void * private_dat
     }
 
 
+    pfile->mode |= O_LARGEFILE;
+
+
     pfile->filp = filp_open(path, pfile->mode, 0);
     
-    if (pfile->filp == NULL) {
+    if (IS_ERR(pfile->filp)) {
        printk("Cannot open file: %s\n", path);
        return NULL;
     }
@@ -170,6 +308,7 @@ static struct v3_file_hooks palacios_file_hooks = {
        .read           = palacios_file_read,
        .write          = palacios_file_write,
        .size           = palacios_file_size,
+       .mkdir          = palacios_file_mkdir,
 };
 
 
@@ -198,6 +337,7 @@ static int guest_file_init(struct v3_guest * guest, void ** vm_data) {
 
     *vm_data = state;
 
+
     return 0;
 }