sysfs: crash debugging

[linux-2.6-omap-h63xx.git] / fs / sysfs / file.c

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index c9e4e5091da14c24b185b67419f3207188150f96..ce8339c70a4b21c7b3f958e19bb0c876eda50fcf 100644 (file)
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -19,10 +19,18 @@
 #include <linux/poll.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
+#include <linux/limits.h>
 #include <asm/uaccess.h>
 
 #include "sysfs.h"
 
+/* used in crash dumps to help with debugging */
+static char last_sysfs_file[PATH_MAX];
+void sysfs_printk_last_file(void)
+{
+       printk(KERN_EMERG "last sysfs file: %s\n", last_sysfs_file);
+}
+
 /*
  * There's one sysfs_buffer for each open file and one
  * sysfs_open_dirent for each sysfs_dirent with one or more open
@@ -328,6 +336,11 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
        struct sysfs_buffer *buffer;
        struct sysfs_ops *ops;
        int error = -EACCES;
+       char *p;
+
+       p = d_path(&file->f_path, last_sysfs_file, sizeof(last_sysfs_file));
+       if (p)
+               memmove(last_sysfs_file, p, strlen(p) + 1);
 
        /* need attr_sd for attr and ops, its parent for kobj */
        if (!sysfs_get_active_two(attr_sd))