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From: Christoph Hellwig <hch@lst.de>
To: Andrew Morton <akpm@linux-foundation.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-rtc@vger.kernel.org,
	Alessandro Zummo <a.zummo@towertech.it>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
	linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	jfs-discussion@lists.sourceforge.net,
	linux-afs@lists.infradead.org, linux-acpi@vger.kernel.org,
	netdev@vger.kernel.org, netfilter-devel@vger.kernel.org,
	Jiri Slaby <jslaby@suse.com>,
	linux-ext4@vger.kernel.org, Alexey Dobriyan <adobriyan@gmail.com>,
	megaraidlinux.pdl@broadcom.com, drbd-dev@lists.linbit.com
Subject: [PATCH 02/40] proc: simplify proc_register calling conventions
Date: Wed, 25 Apr 2018 17:47:49 +0200	[thread overview]
Message-ID: <20180425154827.32251-3-hch@lst.de> (raw)
In-Reply-To: <20180425154827.32251-1-hch@lst.de>

Return registered entry on success, return NULL on failure and free the
passed in entry.  Also expose it in internal.h as we'll start using it
in proc_net.c soon.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/proc/generic.c  | 44 ++++++++++++++++++--------------------------
 fs/proc/internal.h |  2 ++
 2 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 2078e70e1595..bd8480ff0d35 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -346,13 +346,12 @@ static const struct inode_operations proc_dir_inode_operations = {
 	.setattr	= proc_notify_change,
 };
 
-static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
+/* returns the registered entry, or frees dp and returns NULL on failure */
+struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
+		struct proc_dir_entry *dp)
 {
-	int ret;
-
-	ret = proc_alloc_inum(&dp->low_ino);
-	if (ret)
-		return ret;
+	if (proc_alloc_inum(&dp->low_ino))
+		goto out_free_entry;
 
 	write_lock(&proc_subdir_lock);
 	dp->parent = dir;
@@ -360,12 +359,16 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp
 		WARN(1, "proc_dir_entry '%s/%s' already registered\n",
 		     dir->name, dp->name);
 		write_unlock(&proc_subdir_lock);
-		proc_free_inum(dp->low_ino);
-		return -EEXIST;
+		goto out_free_inum;
 	}
 	write_unlock(&proc_subdir_lock);
 
-	return 0;
+	return dp;
+out_free_inum:
+	proc_free_inum(dp->low_ino);
+out_free_entry:
+	pde_free(dp);
+	return NULL;
 }
 
 static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
@@ -443,10 +446,7 @@ struct proc_dir_entry *proc_symlink(const char *name,
 		if (ent->data) {
 			strcpy((char*)ent->data,dest);
 			ent->proc_iops = &proc_link_inode_operations;
-			if (proc_register(parent, ent) < 0) {
-				pde_free(ent);
-				ent = NULL;
-			}
+			ent = proc_register(parent, ent);
 		} else {
 			pde_free(ent);
 			ent = NULL;
@@ -470,11 +470,9 @@ struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
 		ent->proc_fops = &proc_dir_operations;
 		ent->proc_iops = &proc_dir_inode_operations;
 		parent->nlink++;
-		if (proc_register(parent, ent) < 0) {
-			pde_free(ent);
+		ent = proc_register(parent, ent);
+		if (!ent)
 			parent->nlink--;
-			ent = NULL;
-		}
 	}
 	return ent;
 }
@@ -505,11 +503,9 @@ struct proc_dir_entry *proc_create_mount_point(const char *name)
 		ent->proc_fops = NULL;
 		ent->proc_iops = NULL;
 		parent->nlink++;
-		if (proc_register(parent, ent) < 0) {
-			pde_free(ent);
+		ent = proc_register(parent, ent);
+		if (!ent)
 			parent->nlink--;
-			ent = NULL;
-		}
 	}
 	return ent;
 }
@@ -539,11 +535,7 @@ struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
 	pde->proc_fops = proc_fops;
 	pde->data = data;
 	pde->proc_iops = &proc_file_inode_operations;
-	if (proc_register(parent, pde) < 0)
-		goto out_free;
-	return pde;
-out_free:
-	pde_free(pde);
+	return proc_register(parent, pde);
 out:
 	return NULL;
 }
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 0f1692e63cb6..488e67490312 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -162,6 +162,8 @@ extern bool proc_fill_cache(struct file *, struct dir_context *, const char *, i
 /*
  * generic.c
  */
+struct proc_dir_entry *proc_register(struct proc_dir_entry *dir,
+		struct proc_dir_entry *dp);
 extern struct dentry *proc_lookup(struct inode *, struct dentry *, unsigned int);
 struct dentry *proc_lookup_de(struct inode *, struct dentry *, struct proc_dir_entry *);
 extern int proc_readdir(struct file *, struct dir_context *);
-- 
2.17.0

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  parent reply	other threads:[~2018-04-25 15:47 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-25 15:47 simplify procfs code for seq_file instances V2 Christoph Hellwig
2018-04-25 15:47 ` [PATCH 01/40] net/can: single_open_net needs to be paired with single_release_net Christoph Hellwig
2018-04-25 15:47 ` Christoph Hellwig [this message]
2018-04-25 15:47 ` [PATCH 03/40] proc: add a proc_create_reg helper Christoph Hellwig
2018-04-25 15:47 ` [PATCH 04/40] proc: introduce proc_create_seq{,_data} Christoph Hellwig
2018-04-25 15:47 ` [PATCH 05/40] proc: introduce proc_create_seq_private Christoph Hellwig
2018-04-25 15:47 ` [PATCH 06/40] proc: introduce proc_create_single{,_data} Christoph Hellwig
2018-04-26  1:45   ` Finn Thain
2018-05-15 13:58     ` Christoph Hellwig
2018-04-25 15:47 ` [PATCH 07/40] ipv{4,6}/udp{,lite}: simplify proc registration Christoph Hellwig
2018-04-25 15:47 ` [PATCH 08/40] ipv{4,6}/tcp: simplify procfs registration Christoph Hellwig
2018-04-25 15:47 ` [PATCH 09/40] ipv{4,6}/ping: simplify proc file creation Christoph Hellwig
2018-04-25 15:47 ` [PATCH 10/40] ipv{4, 6}/raw: simplify ѕeq_file code Christoph Hellwig
2018-04-25 15:47 ` [PATCH 11/40] ipv6/flowlabel: simplify pid namespace lookup Christoph Hellwig
2018-05-05 12:37   ` Eric W. Biederman
2018-05-15 14:56     ` Christoph Hellwig
2018-05-17  5:28       ` Eric W. Biederman
2018-05-17  6:42         ` Christoph Hellwig
2018-05-17 19:14           ` Eric W. Biederman
2018-04-25 15:47 ` [PATCH 12/40] net/kcm: simplify proc registration Christoph Hellwig
2018-04-25 15:48 ` [PATCH 13/40] netfilter/x_tables: simplify ѕeq_file code Christoph Hellwig
2018-04-25 15:48 ` [PATCH 14/40] net: move seq_file_single_net to <linux/seq_file_net.h> Christoph Hellwig
2018-04-25 15:48 ` [PATCH 15/40] proc: introduce proc_create_net{,_data} Christoph Hellwig
2018-04-25 15:48 ` [PATCH 16/40] proc: introduce proc_create_net_single Christoph Hellwig
2018-04-25 15:48 ` [PATCH 17/40] acpi/battery: simplify procfs code Christoph Hellwig
2018-04-25 15:48 ` [PATCH 18/40] sgi-gru: " Christoph Hellwig
2018-04-25 15:48 ` [PATCH 19/40] megaraid: " Christoph Hellwig
2018-04-25 15:48 ` [PATCH 20/40] sg: " Christoph Hellwig
2018-04-25 15:48 ` [PATCH 21/40] afs: " Christoph Hellwig
2018-04-30 23:20   ` [PATCH 0/3] afs: Network-namespacing and proc David Howells
2018-04-30 23:20     ` [PATCH 1/3] afs: Rearrange fs/afs/proc.c David Howells
2018-05-15 13:43       ` Christoph Hellwig
2018-04-30 23:20     ` [PATCH 2/3] proc: Add a way to make network proc files writable David Howells
2018-05-15 13:48       ` Christoph Hellwig
2018-05-15 14:16       ` David Howells
2018-04-30 23:20     ` [PATCH 3/3] afs: Implement namespacing David Howells
2018-05-15 13:53       ` Christoph Hellwig
2018-05-15 14:28       ` 'Adding' a writable proc file under /proc/net/afs/ [was [PATCH 3/3] afs: Implement namespacing] David Howells
2018-04-25 15:48 ` [PATCH 22/40] ext4: simplify procfs code Christoph Hellwig
2018-04-25 15:48 ` [PATCH 23/40] jfs: " Christoph Hellwig
2018-04-25 15:48 ` [PATCH 24/40] staging/rtl8192u: " Christoph Hellwig
2018-04-25 15:48 ` [PATCH 25/40] resource: switch to proc_create_seq_data Christoph Hellwig
2018-04-25 15:48 ` [PATCH 26/40] drbd: switch to proc_create_single Christoph Hellwig
2018-04-25 15:48 ` [PATCH 27/40] rtc/proc: switch to proc_create_single_data Christoph Hellwig
2018-04-25 18:25   ` Alexandre Belloni
2018-04-25 15:48 ` [PATCH 28/40] bonding: switch to proc_create_seq_data Christoph Hellwig
2018-04-25 15:48 ` [PATCH 29/40] hostap: switch to proc_create_{seq,single}_data Christoph Hellwig
2018-04-25 15:48 ` [PATCH 30/40] neigh: switch to proc_create_seq_data Christoph Hellwig
2018-04-25 15:48 ` [PATCH 31/40] netfilter/xt_hashlimit: switch to proc_create_{seq, single}_data Christoph Hellwig
2018-04-25 15:48 ` [PATCH 32/40] netfilter/x_tables: switch to proc_create_seq_private Christoph Hellwig
2018-04-25 15:48 ` [PATCH 33/40] bluetooth: switch to proc_create_seq_data Christoph Hellwig
2018-04-25 15:48 ` [PATCH 34/40] atm: simplify procfs code Christoph Hellwig
2018-05-05 12:51   ` Eric W. Biederman
2018-05-15 14:12     ` Christoph Hellwig
2018-05-17  1:15       ` Eric W. Biederman
2018-04-25 15:48 ` [PATCH 35/40] atm: switch to proc_create_seq_private Christoph Hellwig
2018-04-25 15:48 ` [PATCH 36/40] isdn: replace ->proc_fops with ->proc_show Christoph Hellwig
2018-04-25 15:48 ` [PATCH 37/40] proc: don't detour through seq->private to get the inode Christoph Hellwig
2018-04-25 15:48 ` [PATCH 38/40] ide: remove ide_driver_proc_write Christoph Hellwig
2018-05-05 13:09   ` Eric W. Biederman
2018-04-25 15:48 ` [PATCH 39/40] ide: replace ->proc_fops with ->proc_show Christoph Hellwig
2018-04-25 15:48 ` [PATCH 40/40] tty: " Christoph Hellwig
2018-04-30 13:19 ` [PATCH 04/40] proc: introduce proc_create_seq{,_data} David Howells
2018-05-15 14:42   ` Christoph Hellwig
2018-04-30 15:38 ` simplify procfs code for seq_file instances V2 David Howells
2018-05-06 17:19 ` Alexey Dobriyan
2018-05-06 17:45   ` Al Viro
2018-05-09 16:53     ` Alexey Dobriyan
2018-05-15 14:03   ` Christoph Hellwig

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