From: Dawid Osuchowski <linux@osuchow.ski>
To: linux-fsdevel@vger.kernel.org
Cc: viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz,
Dawid Osuchowski <linux@osuchow.ski>
Subject: [PATCH v3] fs: Create anon_inode_getfile_fmode()
Date: Fri, 26 Apr 2024 09:58:54 +0200 [thread overview]
Message-ID: <20240426075854.4723-1-linux@osuchow.ski> (raw)
Creates an anon_inode_getfile_fmode() function that works similarly to
anon_inode_getfile() with the addition of being able to set the fmode
member.
Signed-off-by: Dawid Osuchowski <linux@osuchow.ski>
---
Changes since v1:
* removed __anon_inode_create_getfile_fmode()
* streamlined if statement and got rid of goto
Changes since v2:
* changed unsigned int for f_mode into fmode_t in anon_inodes.h
* added <linux/types.h> header to anon_inodes.h
---
fs/anon_inodes.c | 33 +++++++++++++++++++++++++++++++++
include/linux/anon_inodes.h | 5 +++++
2 files changed, 38 insertions(+)
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 0496cb5b6eab..42bd1cb7c9cd 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -148,6 +148,38 @@ struct file *anon_inode_getfile(const char *name,
}
EXPORT_SYMBOL_GPL(anon_inode_getfile);
+/**
+ * anon_inode_getfile_fmode - creates a new file instance by hooking it up to an
+ * anonymous inode, and a dentry that describe the "class"
+ * of the file
+ *
+ * @name: [in] name of the "class" of the new file
+ * @fops: [in] file operations for the new file
+ * @priv: [in] private data for the new file (will be file's private_data)
+ * @flags: [in] flags
+ * @f_mode: [in] fmode
+ *
+ * Creates a new file by hooking it on a single inode. This is useful for files
+ * that do not need to have a full-fledged inode in order to operate correctly.
+ * All the files created with anon_inode_getfile() will share a single inode,
+ * hence saving memory and avoiding code duplication for the file/inode/dentry
+ * setup. Allows setting the fmode. Returns the newly created file* or an error
+ * pointer.
+ */
+struct file *anon_inode_getfile_fmode(const char *name,
+ const struct file_operations *fops,
+ void *priv, int flags, fmode_t f_mode)
+{
+ struct file *file;
+
+ file = __anon_inode_getfile(name, fops, priv, flags, NULL, false);
+ if (!IS_ERR(file))
+ file->f_mode |= f_mode;
+
+ return file;
+}
+EXPORT_SYMBOL_GPL(anon_inode_getfile_fmode);
+
/**
* anon_inode_create_getfile - Like anon_inode_getfile(), but creates a new
* !S_PRIVATE anon inode rather than reuse the
@@ -271,6 +303,7 @@ int anon_inode_create_getfd(const char *name, const struct file_operations *fops
return __anon_inode_getfd(name, fops, priv, flags, context_inode, true);
}
+
static int __init anon_inode_init(void)
{
anon_inode_mnt = kern_mount(&anon_inode_fs_type);
diff --git a/include/linux/anon_inodes.h b/include/linux/anon_inodes.h
index 93a5f16d03f3..edef565c2a1a 100644
--- a/include/linux/anon_inodes.h
+++ b/include/linux/anon_inodes.h
@@ -9,12 +9,17 @@
#ifndef _LINUX_ANON_INODES_H
#define _LINUX_ANON_INODES_H
+#include <linux/types.h>
+
struct file_operations;
struct inode;
struct file *anon_inode_getfile(const char *name,
const struct file_operations *fops,
void *priv, int flags);
+struct file *anon_inode_getfile_fmode(const char *name,
+ const struct file_operations *fops,
+ void *priv, int flags, fmode_t f_mode);
struct file *anon_inode_create_getfile(const char *name,
const struct file_operations *fops,
void *priv, int flags,
--
2.44.0
next reply other threads:[~2024-04-26 7:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 7:58 Dawid Osuchowski [this message]
2024-04-26 16:05 ` [PATCH v3] fs: Create anon_inode_getfile_fmode() Christian Brauner
2024-05-08 0:41 ` Al Viro
2024-05-08 0:46 ` Al Viro
2024-05-08 11:37 ` Christian Brauner
2024-05-08 1:48 ` Al Viro
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