ext4: simplify ext4 error translation

We convert errno's to ext4 on-disk format error codes in
save_error_info(). Add a function and a bit of macro magic to make this
simpler.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201127113405.26867-7-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 88d19f3..0e6d9a4 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -551,76 +551,61 @@ static bool system_going_down(void)
                || system_state == SYSTEM_RESTART;
 }
 
+struct ext4_err_translation {
+       int code;
+       int errno;
+};
+
+#define EXT4_ERR_TRANSLATE(err) { .code = EXT4_ERR_##err, .errno = err }
+
+static struct ext4_err_translation err_translation[] = {
+       EXT4_ERR_TRANSLATE(EIO),
+       EXT4_ERR_TRANSLATE(ENOMEM),
+       EXT4_ERR_TRANSLATE(EFSBADCRC),
+       EXT4_ERR_TRANSLATE(EFSCORRUPTED),
+       EXT4_ERR_TRANSLATE(ENOSPC),
+       EXT4_ERR_TRANSLATE(ENOKEY),
+       EXT4_ERR_TRANSLATE(EROFS),
+       EXT4_ERR_TRANSLATE(EFBIG),
+       EXT4_ERR_TRANSLATE(EEXIST),
+       EXT4_ERR_TRANSLATE(ERANGE),
+       EXT4_ERR_TRANSLATE(EOVERFLOW),
+       EXT4_ERR_TRANSLATE(EBUSY),
+       EXT4_ERR_TRANSLATE(ENOTDIR),
+       EXT4_ERR_TRANSLATE(ENOTEMPTY),
+       EXT4_ERR_TRANSLATE(ESHUTDOWN),
+       EXT4_ERR_TRANSLATE(EFAULT),
+};
+
+static int ext4_errno_to_code(int errno)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(err_translation); i++)
+               if (err_translation[i].errno == errno)
+                       return err_translation[i].code;
+       return EXT4_ERR_UNKNOWN;
+}
+
 static void __save_error_info(struct super_block *sb, int error,
                              __u32 ino, __u64 block,
                              const char *func, unsigned int line)
 {
        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
-       int err;
 
        EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
        if (bdev_read_only(sb->s_bdev))
                return;
+       /* We default to EFSCORRUPTED error... */
+       if (error == 0)
+               error = EFSCORRUPTED;
        es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
        ext4_update_tstamp(es, s_last_error_time);
        strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
        es->s_last_error_line = cpu_to_le32(line);
        es->s_last_error_ino = cpu_to_le32(ino);
        es->s_last_error_block = cpu_to_le64(block);
-       switch (error) {
-       case EIO:
-               err = EXT4_ERR_EIO;
-               break;
-       case ENOMEM:
-               err = EXT4_ERR_ENOMEM;
-               break;
-       case EFSBADCRC:
-               err = EXT4_ERR_EFSBADCRC;
-               break;
-       case 0:
-       case EFSCORRUPTED:
-               err = EXT4_ERR_EFSCORRUPTED;
-               break;
-       case ENOSPC:
-               err = EXT4_ERR_ENOSPC;
-               break;
-       case ENOKEY:
-               err = EXT4_ERR_ENOKEY;
-               break;
-       case EROFS:
-               err = EXT4_ERR_EROFS;
-               break;
-       case EFBIG:
-               err = EXT4_ERR_EFBIG;
-               break;
-       case EEXIST:
-               err = EXT4_ERR_EEXIST;
-               break;
-       case ERANGE:
-               err = EXT4_ERR_ERANGE;
-               break;
-       case EOVERFLOW:
-               err = EXT4_ERR_EOVERFLOW;
-               break;
-       case EBUSY:
-               err = EXT4_ERR_EBUSY;
-               break;
-       case ENOTDIR:
-               err = EXT4_ERR_ENOTDIR;
-               break;
-       case ENOTEMPTY:
-               err = EXT4_ERR_ENOTEMPTY;
-               break;
-       case ESHUTDOWN:
-               err = EXT4_ERR_ESHUTDOWN;
-               break;
-       case EFAULT:
-               err = EXT4_ERR_EFAULT;
-               break;
-       default:
-               err = EXT4_ERR_UNKNOWN;
-       }
-       es->s_last_error_errcode = err;
+       es->s_last_error_errcode = ext4_errno_to_code(error);
        if (!es->s_first_error_time) {
                es->s_first_error_time = es->s_last_error_time;
                es->s_first_error_time_hi = es->s_last_error_time_hi;