Implement read parts of tmpfs

mehfooz09 · Feb 17, 2020 · 823647b · 823647b
1 parent 580b3b9
commit 823647b
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Showing 8 changed files with 499 additions and 14 deletions.
diff --git a/fs/fd.h b/fs/fd.h
@@ -72,7 +72,7 @@ struct fd {
             // length of actual data stored in the buffer
             size_t buffer_len;
         } clipboard;
-        
+
         // can fit anything in here
         void *data;
     };
@@ -86,6 +86,11 @@ struct fd {
         struct {
             int num;
         } devpts;
+        struct {
+            struct tmp_dirent *dirent;
+            struct tmp_dirent *dir_pos;
+        } tmpfs;
+        void *fs_data;
     };
 
     // fs/inode data

diff --git a/fs/mount.c b/fs/mount.c
@@ -8,6 +8,7 @@ const struct fs_ops *filesystems[] = {
     &realfs,
     &procfs,
     &devptsfs,
+    &tmpfs,
 };
 
 struct mount *mount_find(char *path) {

diff --git a/fs/path.c b/fs/path.c
@@ -154,3 +154,23 @@ bool path_is_normalized(const char *path) {
     }
     return true;
 }
+
+bool path_next_component(const char **path, char *component, int *err) {
+    const char *p = *path;
+    if (*p == '\0')
+        return false;
+
+    assert(*p == '/');
+    p++;
+    char *c = component;
+    while (*p != '/' && *p != '\0') {
+        *c++ = *p++;
+        if (c - component >= MAX_NAME) {
+            *err = _ENAMETOOLONG;
+            return false;
+        }
+    }
+    *c = '\0';
+    *path = p;
+    return true;
+}
diff --git a/fs/path.h b/fs/path.h
@@ -26,4 +26,15 @@
 int path_normalize(struct fd *at, const char *path, char *out, int flags);
 bool path_is_normalized(const char *path);
 
+// Helper function for iterating through a normalized path.
+//
+// The *path pointer is advanced to point to the next /, and the next path
+// component is copied to component. component must point to a buffer large
+// enough to hold a string of MAX_NAME characters.
+//
+// If the next path component was successfully copied, returns true; otherwise
+// returns false. If an error occurred, *err is set to the error code.
+// Otherwise, the end of the path has been reached.
+bool path_next_component(const char **path, char *component, int *err);
+
 #endif
diff --git a/fs/proc.c b/fs/proc.c
@@ -3,24 +3,16 @@
 #include "kernel/calls.h"
 #include "kernel/fs.h"
 #include "fs/proc.h"
+#include "fs/path.h"
 
 static int proc_lookup(const char *path, struct proc_entry *entry) {
     entry->meta = &proc_root;
-    char component[MAX_NAME + 1] = {};
-    while (*path != '\0') {
+    char component[MAX_NAME + 1];
+    int err = 0;
+    while (path_next_component(&path, component, &err)) {
         if (!S_ISDIR(proc_entry_mode(entry)))
             return _ENOTDIR;
 
-        assert(*path == '/');
-        path++;
-        char *c = component;
-        while (*path != '/' && *path != '\0') {
-            *c++ = *path++;
-            if (c - component >= MAX_NAME)
-                return _ENAMETOOLONG;
-        }
-        *c = '\0';
-
         unsigned long index = 0;
         struct proc_entry next_entry;
         char entry_name[MAX_NAME];
@@ -42,7 +34,7 @@ static int proc_lookup(const char *path, struct proc_entry *entry) {
 found:
         *entry = next_entry;
     }
-    return 0;
+    return err;
 }
 
 extern const struct fd_ops procfs_fdops;