From: Lenny Szubowicz Date: Fri, 28 Jun 2013 21:11:33 +0000 (-0400) Subject: pstore: Return unique error if backend registration excluded by kernel param X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8e48b1a8ed58595c40f2748c0f2da55b04da2dd6;p=linux-beck.git pstore: Return unique error if backend registration excluded by kernel param This is patch 1/3 of a patch set that avoids what misleadingly appears to be a error during boot: ERST: Could not register with persistent store This message is displayed if the system has a valid ACPI ERST table and the pstore.backend kernel parameter has been used to disable use of ERST by pstore. But this same message is used for errors that preclude registration. As part of fixing this, return a unique error status from pstore_register if the pstore.backend kernel parameter selects a specific facility other than the requesting facility and check for this condition before any others. This allows the caller to distinquish this benign case from the other failure cases. Also, print an informational console message about which facility successfully registered as the pstore backend. Since there are various kernel parameters, config build options, and boot-time errors that can influence which facility registers with pstore, it's useful to have a positive indication. Signed-off-by: Lenny Szubowicz Reported-by: Naotaka Hamaguchi Signed-off-by: Tony Luck --- diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 86d1038b5a12..b7ffe2bcd9c4 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -239,17 +239,15 @@ int pstore_register(struct pstore_info *psi) { struct module *owner = psi->owner; + if (backend && strcmp(backend, psi->name)) + return -EPERM; + spin_lock(&pstore_lock); if (psinfo) { spin_unlock(&pstore_lock); return -EBUSY; } - if (backend && strcmp(backend, psi->name)) { - spin_unlock(&pstore_lock); - return -EINVAL; - } - if (!psi->write) psi->write = pstore_write_compat; psinfo = psi; @@ -274,6 +272,9 @@ int pstore_register(struct pstore_info *psi) add_timer(&pstore_timer); } + pr_info("pstore: Registered %s as persistent store backend\n", + psi->name); + return 0; } EXPORT_SYMBOL_GPL(pstore_register);