LU-4795 obd: Remove server_{get,put}_mount_2() functions

This patch fixes server_put_mount() to call server_deregister_mount()
only if the caller is never going to need the mount again. The only
caller of server_get_mount_2(), lustre_find_lwp_by_index(), is
changed to now call server_get_mount() and server_put_mount()
without calling server_deregister_mount().

Signed-off-by: Swapnil Pimpale <spimpale@ddn.com>
Change-Id: I37fd00bd477f946ac1bd8375da4899c2a1fe9e22
Reviewed-on: http://review.whamcloud.com/9749
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>

diff --git a/lustre/include/lustre_disk.h b/lustre/include/lustre_disk.h
index a61f7be..567e194 100644 (file)
--- a/lustre/include/lustre_disk.h
+++ b/lustre/include/lustre_disk.h
@@ -548,9 +548,7 @@ int lustre_common_put_super(struct super_block *sb);
 /* obd_mount_server.c */
 int server_fill_super(struct super_block *sb);
 struct lustre_mount_info *server_get_mount(const char *name);
-struct lustre_mount_info *server_get_mount_2(const char *name);
-int server_put_mount(const char *name);
-int server_put_mount_2(const char *name, struct vfsmount *mnt);
+int server_put_mount(const char *name, bool dereg_mnt);
 struct mgs_target_info;
 int server_mti_print(const char *title, struct mgs_target_info *mti);
 void server_calc_timeout(struct lustre_sb_info *lsi, struct obd_device *obd);

diff --git a/lustre/mdt/mdt_handler.c b/lustre/mdt/mdt_handler.c
index a0b8b55..9f84d08 100644 (file)
--- a/lustre/mdt/mdt_handler.c
+++ b/lustre/mdt/mdt_handler.c
@@ -4389,7 +4389,7 @@ static void mdt_fini(const struct lu_env *env, struct mdt_device *m)
 
        LASSERT(atomic_read(&d->ld_ref) == 0);
 
-       server_put_mount(mdt_obd_name(m));
+       server_put_mount(mdt_obd_name(m), true);
 
        EXIT;
 }
@@ -4645,7 +4645,7 @@ err_fini_stack:
        mdt_stack_fini(env, m, md2lu_dev(m->mdt_child));
 err_lmi:
        if (lmi)
-               server_put_mount(dev);
+               server_put_mount(dev, true);
        return(rc);
 }
 

diff --git a/lustre/mgs/mgs_handler.c b/lustre/mgs/mgs_handler.c
index 48209ac..b0c5be7 100644 (file)
--- a/lustre/mgs/mgs_handler.c
+++ b/lustre/mgs/mgs_handler.c
@@ -1232,7 +1232,7 @@ err_ops:
        obd_disconnect(mgs->mgs_bottom_exp);
 err_lmi:
        if (lmi)
-               server_put_mount(lustre_cfg_string(lcfg, 0));
+               server_put_mount(lustre_cfg_string(lcfg, 0), true);
        RETURN(rc);
 }
 
@@ -1404,7 +1404,7 @@ static struct lu_device *mgs_device_fini(const struct lu_env *env,
        LASSERT(mgs->mgs_bottom_exp);
        obd_disconnect(mgs->mgs_bottom_exp);
 
-       server_put_mount(obd->obd_name);
+       server_put_mount(obd->obd_name, true);
 
        RETURN(NULL);
 }

diff --git a/lustre/obdclass/obd_mount.c b/lustre/obdclass/obd_mount.c
index f6e4690..2289b8d 100644 (file)
--- a/lustre/obdclass/obd_mount.c
+++ b/lustre/obdclass/obd_mount.c
@@ -645,10 +645,10 @@ static int lustre_free_lsi(struct super_block *sb)
    e.g. MDT, MGS, and potentially MGC */
 int lustre_put_lsi(struct super_block *sb)
 {
-        struct lustre_sb_info *lsi = s2lsi(sb);
-        ENTRY;
+       struct lustre_sb_info *lsi = s2lsi(sb);
+       ENTRY;
 
-        LASSERT(lsi != NULL);
+       LASSERT(lsi != NULL);
 
        CDEBUG(D_MOUNT, "put %p %d\n", sb, atomic_read(&lsi->lsi_mounts));
        if (atomic_dec_and_test(&lsi->lsi_mounts)) {
@@ -660,10 +660,10 @@ int lustre_put_lsi(struct super_block *sb)
                        /* wait till OSD is gone */
                        obd_zombie_barrier();
                }
-                lustre_free_lsi(sb);
-                RETURN(1);
-        }
-        RETURN(0);
+               lustre_free_lsi(sb);
+               RETURN(1);
+       }
+       RETURN(0);
 }
 
 /*** SERVER NAME ***

diff --git a/lustre/obdclass/obd_mount_server.c b/lustre/obdclass/obd_mount_server.c
index d67963b..02d2cb0 100644 (file)
--- a/lustre/obdclass/obd_mount_server.c
+++ b/lustre/obdclass/obd_mount_server.c
@@ -173,28 +173,19 @@ struct lustre_mount_info *server_get_mount(const char *name)
 }
 EXPORT_SYMBOL(server_get_mount);
 
-/*
- * Used by mdt to get mount_info from obdname.
- * There are no blocking when using the mount_info.
- * Do not use server_get_mount for this purpose.
+/**
+ * server_put_mount: to be called from obd_cleanup methods
+ * @name:      obd name
+ * @dereg_mnt: 0 or 1 depending on whether the mount is to be deregistered or
+ * not
+ *
+ * The caller decides whether server_deregister_mount() needs to be called or
+ * not. Calling of server_deregister_mount() does not depend on refcounting on
+ * lsi because we could have say the mgs and mds on the same node and we
+ * unmount the mds, then the ref on the lsi would still be non-zero but we
+ * would still want to deregister the mds mount.
  */
-struct lustre_mount_info *server_get_mount_2(const char *name)
-{
-       struct lustre_mount_info *lmi;
-       ENTRY;
-
-       mutex_lock(&lustre_mount_info_lock);
-       lmi = server_find_mount(name);
-       mutex_unlock(&lustre_mount_info_lock);
-       if (!lmi)
-               CERROR("Can't find mount for %s\n", name);
-
-       RETURN(lmi);
-}
-EXPORT_SYMBOL(server_get_mount_2);
-
-/* to be called from obd_cleanup methods */
-int server_put_mount(const char *name)
+int server_put_mount(const char *name, bool dereg_mnt)
 {
        struct lustre_mount_info *lmi;
        struct lustre_sb_info *lsi;
@@ -216,21 +207,14 @@ int server_put_mount(const char *name)
                CDEBUG(D_MOUNT, "Last put of mount %p from %s\n",
                       lmi->lmi_sb, name);
 
-       /* this obd should never need the mount again */
-       server_deregister_mount(name);
+       if (dereg_mnt)
+               /* this obd should never need the mount again */
+               server_deregister_mount(name);
 
        RETURN(0);
 }
 EXPORT_SYMBOL(server_put_mount);
 
-/* Corresponding to server_get_mount_2 */
-int server_put_mount_2(const char *name, struct vfsmount *mnt)
-{
-       ENTRY;
-       RETURN(0);
-}
-EXPORT_SYMBOL(server_put_mount_2);
-
 /* Set up a MGS to serve startup logs */
 static int server_start_mgs(struct super_block *sb)
 {
@@ -468,7 +452,7 @@ struct obd_export *lustre_find_lwp_by_index(const char *dev, __u32 idx)
        char                      lwp_name[24];
        int                       rc;
 
-       lmi = server_get_mount_2(dev);
+       lmi = server_get_mount(dev);
        if (lmi == NULL)
                return NULL;
 
@@ -477,7 +461,7 @@ struct obd_export *lustre_find_lwp_by_index(const char *dev, __u32 idx)
        if (rc != 0) {
                CERROR("%s: failed to get fsname: rc = %d\n",
                       lsi->lsi_svname, rc);
-               return NULL;
+               goto err_lmi;
        }
 
        snprintf(lwp_name, sizeof(lwp_name), "%s-MDT%04x", fsname, idx);
@@ -492,6 +476,9 @@ struct obd_export *lustre_find_lwp_by_index(const char *dev, __u32 idx)
        }
        spin_unlock(&lsi->lsi_lwp_lock);
 
+err_lmi:
+       server_put_mount(dev, false);
+
        return exp;
 }
 EXPORT_SYMBOL(lustre_find_lwp_by_index);

diff --git a/lustre/ofd/ofd_dev.c b/lustre/ofd/ofd_dev.c
index 4e4fd1c..7f24f32 100644 (file)
--- a/lustre/ofd/ofd_dev.c
+++ b/lustre/ofd/ofd_dev.c
@@ -2293,7 +2293,7 @@ static void ofd_fini(const struct lu_env *env, struct ofd_device *m)
        ofd_stack_fini(env, m, &m->ofd_dt_dev.dd_lu_dev);
        ofd_procfs_fini(m);
        LASSERT(atomic_read(&d->ld_ref) == 0);
-       server_put_mount(obd->obd_name);
+       server_put_mount(obd->obd_name, true);
        EXIT;
 }