Merge trivial changes from branch to head.

[fs/lustre-release.git] / lustre / lib / simple.c

diff --git a/lustre/lib/simple.c b/lustre/lib/simple.c
index dee3013..3a34247 100644 (file)
--- a/lustre/lib/simple.c
+++ b/lustre/lib/simple.c
@@ -24,10 +24,26 @@
 #include <linux/lustre_lib.h>
 #include <linux/lustre_net.h>
 
+#ifdef OBD_CTXT_DEBUG
+/* Debugging check only needed during development */
+#define ASSERT_CTXT_MAGIC(magic) do { if ((magic) != OBD_RUN_CTXT_MAGIC) { \
+                                CERROR("bad ctxt magic\n"); LBUG(); } } while(0)
+#define ASSERT_NOT_KERNEL_CTXT(msg) do { if (segment_eq(get_fs(), get_ds())) { \
+                                        CERROR(msg); LBUG(); } } while(0)
+#define ASSERT_KERNEL_CTXT(msg) do { if (!segment_eq(get_fs(), get_ds())) { \
+                                        CERROR(msg); LBUG(); } } while(0)
+#else
+#define ASSERT_CTXT_MAGIC(magic) do {} while(0)
+#define ASSERT_NOT_KERNEL_CTXT(msg) do {} while(0)
+#define ASSERT_KERNEL_CTXT(msg) do {} while(0)
+#endif
 
 /* push / pop to root of obd store */
 void push_ctxt(struct obd_run_ctxt *save, struct obd_run_ctxt *new)
 {
+        //ASSERT_NOT_KERNEL_CTXT("already in kernel context!\n");
+        ASSERT_CTXT_MAGIC(new->magic);
+        OBD_SET_CTXT_MAGIC(save);
         save->fs = get_fs();
         save->pwd = dget(current->fs->pwd);
         save->pwdmnt = mntget(current->fs->pwdmnt);
@@ -38,6 +54,8 @@ void push_ctxt(struct obd_run_ctxt *save, struct obd_run_ctxt *new)
 
 void pop_ctxt(struct obd_run_ctxt *saved)
 {
+        ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
+        ASSERT_CTXT_MAGIC(saved->magic);
         set_fs(saved->fs);
         set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 
@@ -52,17 +70,18 @@ struct dentry *simple_mkdir(struct dentry *dir, char *name, int mode)
         int err;
         ENTRY;
 
-       CDEBUG(D_INODE, "creating directory %*s\n", strlen(name), name);
+        ASSERT_KERNEL_CTXT("kernel doing mkdir outside kernel context\n");
+        CDEBUG(D_INODE, "creating directory %*s\n", strlen(name), name);
         dchild = lookup_one_len(name, dir, strlen(name));
         if (IS_ERR(dchild))
                 RETURN(dchild);
 
         if (dchild->d_inode) {
-               if (!S_ISDIR(dchild->d_inode->i_mode))
-                       GOTO(out, err = -ENOTDIR);
+                if (!S_ISDIR(dchild->d_inode->i_mode))
+                        GOTO(out, err = -ENOTDIR);
 
                 RETURN(dchild);
-       }
+        }
 
         err = vfs_mkdir(dir->d_inode, dchild, mode);
         EXIT;
@@ -75,29 +94,44 @@ out:
         RETURN(dchild);
 }
 
+/*
+ * Read a file from within kernel context.  Prior to calling this
+ * function we should already have done a push_ctxt().
+ */
 int lustre_fread(struct file *file, char *str, int len, loff_t *off)
 {
-       if (!file || !file->f_op || !file->f_op->read || !off)
-               RETURN(-ENOSYS);
+        ASSERT_KERNEL_CTXT("kernel doing read outside kernel context\n");
+        if (!file || !file->f_op || !file->f_op->read || !off)
+                RETURN(-ENOSYS);
 
-       return file->f_op->read(file, str, len, off);
+        return file->f_op->read(file, str, len, off);
 }
 
+/*
+ * Write a file from within kernel context.  Prior to calling this
+ * function we should already have done a push_ctxt().
+ */
 int lustre_fwrite(struct file *file, const char *str, int len, loff_t *off)
 {
-       if (!file || !file->f_op || !off)
-               RETURN(-ENOSYS);
+        ASSERT_KERNEL_CTXT("kernel doing write outside kernel context\n");
+        if (!file || !file->f_op || !off)
+                RETURN(-ENOSYS);
 
-       if (!file->f_op->write)
-               RETURN(-EROFS);
+        if (!file->f_op->write)
+                RETURN(-EROFS);
 
-       return file->f_op->write(file, str, len, off);
+        return file->f_op->write(file, str, len, off);
 }
 
+/*
+ * Sync a file from within kernel context.  Prior to calling this
+ * function we should already have done a push_ctxt().
+ */
 int lustre_fsync(struct file *file)
 {
-       if (!file || !file->f_op || !file->f_op->fsync)
-               RETURN(-ENOSYS);
+        ASSERT_KERNEL_CTXT("kernel doing sync outside kernel context\n");
+        if (!file || !file->f_op || !file->f_op->fsync)
+                RETURN(-ENOSYS);
 
-       return file->f_op->fsync(file, file->f_dentry, 0);
+        return file->f_op->fsync(file, file->f_dentry, 0);
 }