LU-8066 llite: use more private data in dump_pgcache

The dump_page_cache debugfs file allocates and frees an 'env' in each
call to vvp_pgcache_start,next,show.  This is likely to be fast, but
does introduce the need to check for errors.

It is reasonable to allocate a single 'env' when the file is opened,
and use that throughout.

So create 'seq_private' structure which stores the sbi, env, and
refcheck, and attach this to the seqfile.

Then use it throughout instead of allocating 'env' repeatedly.

Linux-commit: fc5f499af16c247c5bff68d2625a6d1ca48b3332

Test-Parameters: trivial envdefinitions="ONLY=63b" testlist=sanity
Test-Parameters: trivial envdefinitions="ONLY=118" testlist=sanity
Test-Parameters: trivial envdefinitions="ONLY=20" testlist=sanityn

Change-Id: Id7e7f5ec1729d1e5af041adcb247ca11299ed734
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/33009
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/llite/vvp_dev.c b/lustre/llite/vvp_dev.c
index 0ceee42..56b921a 100644 (file)
--- a/lustre/llite/vvp_dev.c
+++ b/lustre/llite/vvp_dev.c
@@ -384,6 +384,12 @@ struct vvp_pgcache_id {
         struct lu_object_header *vpi_obj;
 };
 
+struct vvp_seq_private {
+       struct ll_sb_info       *vsp_sbi;
+       struct lu_env           *vsp_env;
+       u16                     vsp_refcheck;
+};
+
 static void vvp_pgcache_id_unpack(loff_t pos, struct vvp_pgcache_id *id)
 {
        CLASSERT(sizeof(pos) == sizeof(__u64));
@@ -526,92 +532,76 @@ static void vvp_pgcache_page_show(const struct lu_env *env,
 
 static int vvp_pgcache_show(struct seq_file *f, void *v)
 {
-       loff_t                   pos;
-       struct ll_sb_info       *sbi;
-       struct cl_object        *clob;
-       struct lu_env           *env;
-       struct vvp_pgcache_id    id;
-       __u16                    refcheck;
-       int                      result;
-
-       env = cl_env_get(&refcheck);
-       if (!IS_ERR(env)) {
-               pos = *(loff_t *) v;
-               vvp_pgcache_id_unpack(pos, &id);
-               sbi = f->private;
-               clob = vvp_pgcache_obj(env, &sbi->ll_cl->cd_lu_dev, &id);
-               if (clob != NULL) {
-                       struct inode *inode = vvp_object_inode(clob);
-                       struct cl_page *page = NULL;
-                       struct page *vmpage;
-
-                       result = find_get_pages_contig(inode->i_mapping,
-                                                     id.vpi_index, 1, &vmpage);
-                       if (result > 0) {
-                               lock_page(vmpage);
-                               page = cl_vmpage_page(vmpage, clob);
-                               unlock_page(vmpage);
+       struct vvp_seq_private *priv = f->private;
+       loff_t pos;
+       struct cl_object *clob;
+       struct vvp_pgcache_id id;
 
-                               put_page(vmpage);
-                       }
+       pos = *(loff_t *) v;
+       vvp_pgcache_id_unpack(pos, &id);
+       clob = vvp_pgcache_obj(priv->vsp_env, &priv->vsp_sbi->ll_cl->cd_lu_dev,
+                              &id);
+       if (clob) {
+               struct inode *inode = vvp_object_inode(clob);
+               struct cl_page *page = NULL;
+               struct page *vmpage;
+               int result;
+
+               result = find_get_pages_contig(inode->i_mapping,
+                                             id.vpi_index, 1, &vmpage);
+               if (result > 0) {
+                       lock_page(vmpage);
+                       page = cl_vmpage_page(vmpage, clob);
+                       unlock_page(vmpage);
+
+                       put_page(vmpage);
+               }
 
-                       seq_printf(f, "%8x@"DFID": ", id.vpi_index,
-                                  PFID(lu_object_fid(&clob->co_lu)));
-                       if (page != NULL) {
-                               vvp_pgcache_page_show(env, f, page);
-                               cl_page_put(env, page);
-                       } else
-                               seq_puts(f, "missing\n");
-                       lu_object_ref_del(&clob->co_lu, "dump", current);
-                       cl_object_put(env, clob);
-               } else
-                       seq_printf(f, "%llx missing\n", pos);
-               cl_env_put(env, &refcheck);
-               result = 0;
-       } else
-               result = PTR_ERR(env);
-       return result;
+               seq_printf(f, "%8x@" DFID ": ", id.vpi_index,
+                          PFID(lu_object_fid(&clob->co_lu)));
+               if (page) {
+                       vvp_pgcache_page_show(priv->vsp_env, f, page);
+                       cl_page_put(priv->vsp_env, page);
+               } else {
+                       seq_puts(f, "missing\n");
+               }
+               lu_object_ref_del(&clob->co_lu, "dump", current);
+               cl_object_put(priv->vsp_env, clob);
+       } else {
+               seq_printf(f, "%llx missing\n", pos);
+       }
+       return 0;
 }
 
 static void *vvp_pgcache_start(struct seq_file *f, loff_t *pos)
 {
-        struct ll_sb_info *sbi;
-        struct lu_env     *env;
-       __u16              refcheck;
-
-        sbi = f->private;
+       struct vvp_seq_private *priv = f->private;
+
+       if (priv->vsp_sbi->ll_site->ls_obj_hash->hs_cur_bits >
+           64 - PGC_OBJ_SHIFT) {
+               pos = ERR_PTR(-EFBIG);
+       } else {
+               *pos = vvp_pgcache_find(priv->vsp_env,
+                                       &priv->vsp_sbi->ll_cl->cd_lu_dev,
+                                       *pos);
+               if (*pos == ~0ULL)
+                       pos = NULL;
+       }
 
-        env = cl_env_get(&refcheck);
-        if (!IS_ERR(env)) {
-                sbi = f->private;
-                if (sbi->ll_site->ls_obj_hash->hs_cur_bits > 64 - PGC_OBJ_SHIFT)
-                        pos = ERR_PTR(-EFBIG);
-                else {
-                        *pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev,
-                                                *pos);
-                        if (*pos == ~0ULL)
-                                pos = NULL;
-                }
-                cl_env_put(env, &refcheck);
-        }
-        return pos;
+       return pos;
 }
 
 static void *vvp_pgcache_next(struct seq_file *f, void *v, loff_t *pos)
 {
-        struct ll_sb_info *sbi;
-        struct lu_env     *env;
-       __u16              refcheck;
+       struct vvp_seq_private *priv = f->private;
 
-        env = cl_env_get(&refcheck);
-        if (!IS_ERR(env)) {
-                sbi = f->private;
-                *pos = vvp_pgcache_find(env, &sbi->ll_cl->cd_lu_dev, *pos + 1);
-                if (*pos == ~0ULL)
-                        pos = NULL;
-                cl_env_put(env, &refcheck);
-        }
-        return pos;
+       *pos = vvp_pgcache_find(priv->vsp_env,
+                               &priv->vsp_sbi->ll_cl->cd_lu_dev,
+                               *pos + 1);
+       if (*pos == ~0ULL)
+               pos = NULL;
+
+       return pos;
 }
 
 static void vvp_pgcache_stop(struct seq_file *f, void *v)
@@ -628,22 +618,36 @@ static struct seq_operations vvp_pgcache_ops = {
 
 static int vvp_dump_pgcache_seq_open(struct inode *inode, struct file *filp)
 {
-       struct ll_sb_info       *sbi = PDE_DATA(inode);
-       struct seq_file         *seq;
-       int                     result;
-
-       result = seq_open(filp, &vvp_pgcache_ops);
-       if (result == 0) {
-               seq = filp->private_data;
-               seq->private = sbi;
+       struct vvp_seq_private *priv;
+
+       priv = __seq_open_private(filp, &vvp_pgcache_ops, sizeof(*priv));
+       if (!priv)
+               return -ENOMEM;
+
+       priv->vsp_sbi = PDE_DATA(inode);
+       priv->vsp_env = cl_env_get(&priv->vsp_refcheck);
+       if (IS_ERR(priv->vsp_env)) {
+               int err = PTR_ERR(priv->vsp_env);
+
+               seq_release_private(inode, filp);
+               return err;
        }
-       return result;
+       return 0;
+}
+
+static int vvp_dump_pgcache_seq_release(struct inode *inode, struct file *file)
+{
+       struct seq_file *seq = file->private_data;
+       struct vvp_seq_private *priv = seq->private;
+
+       cl_env_put(priv->vsp_env, &priv->vsp_refcheck);
+       return seq_release_private(inode, file);
 }
 
 const struct file_operations vvp_dump_pgcache_file_ops = {
-        .owner   = THIS_MODULE,
-        .open    = vvp_dump_pgcache_seq_open,
-        .read    = seq_read,
-        .llseek         = seq_lseek,
-        .release = seq_release,
+       .owner   = THIS_MODULE,
+       .open    = vvp_dump_pgcache_seq_open,
+       .read    = seq_read,
+       .llseek  = seq_lseek,
+       .release = vvp_dump_pgcache_seq_release,
 };