mount must return EACCES, not EROFS, when one attempts to mount a read-only filesystem in read-write mode, but the file-system layer only transmits the error given by the block layer, and many block drivers return EROFS in that case, so let's fix it in do_mount. Actually it is only a small problem for a user using the mount(1) command, because EROFS is actually a more explicit answer than EACCES, but init/do_mounts.c checks only for EACCES, not EROFS, to decide to retry to mount the root file-system in read-only mode, and so we are left with an unbootable kernel, and with a cryptic error message (*) if the root partition happens to be read-only (*): VFS: Cannot open root device "mmcblk0p2" or unknown-block(179,2): error -30 Signed-off-by: Philippe De Muyter <phdm@xxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: linux-fsdevel@xxxxxxxxxxxxxxx --- fs/namespace.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 182bc41..6291a3f 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2411,6 +2411,8 @@ long do_mount(const char *dev_name, const char *dir_name, retval = security_sb_mount(dev_name, &path, type_page, flags, data_page); + if (retval == -EROFS) + retval = -EACCES; if (!retval && !may_mount()) retval = -EPERM; if (retval) -- 1.7.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
