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author | Gu Zheng <guz.fnst@cn.fujitsu.com> | 2013-07-16 17:56:12 +0800 |
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committer | Benjamin LaHaise <bcrl@kvack.org> | 2013-07-16 09:32:17 -0400 |
commit | 55708698c5f153f4e390175cdfc395333b2eafbd (patch) | |
tree | b1d915cae064e83af09b9e2001c25429e289ad6b | |
parent | 47188d39b5deeebf41f87a02af1b3935866364cf (diff) | |
download | op-kernel-dev-55708698c5f153f4e390175cdfc395333b2eafbd.zip op-kernel-dev-55708698c5f153f4e390175cdfc395333b2eafbd.tar.gz |
fs/anon_inode: Introduce a new lib function anon_inode_getfile_private()
Introduce a new lib function anon_inode_getfile_private(), it creates a new file
instance by hooking it up to an anonymous inode, and a dentry that describe the
"class" of the file, similar to anon_inode_getfile(), but each file holds a
single inode. Furthermore, anyone who wants to create a private anon file will
benefit from this change.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
-rw-r--r-- | fs/anon_inodes.c | 66 | ||||
-rw-r--r-- | include/linux/anon_inodes.h | 3 |
2 files changed, 69 insertions, 0 deletions
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 47a65df..85c9618 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -109,6 +109,72 @@ static struct file_system_type anon_inode_fs_type = { }; /** + * anon_inode_getfile_private - 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 + * + * + * Similar to anon_inode_getfile, but each file holds a single inode. + * + */ +struct file *anon_inode_getfile_private(const char *name, + const struct file_operations *fops, + void *priv, int flags) +{ + struct qstr this; + struct path path; + struct file *file; + struct inode *inode; + + if (fops->owner && !try_module_get(fops->owner)) + return ERR_PTR(-ENOENT); + + inode = anon_inode_mkinode(anon_inode_mnt->mnt_sb); + if (IS_ERR(inode)) { + file = ERR_PTR(-ENOMEM); + goto err_module; + } + + /* + * Link the inode to a directory entry by creating a unique name + * using the inode sequence number. + */ + file = ERR_PTR(-ENOMEM); + this.name = name; + this.len = strlen(name); + this.hash = 0; + path.dentry = d_alloc_pseudo(anon_inode_mnt->mnt_sb, &this); + if (!path.dentry) + goto err_module; + + path.mnt = mntget(anon_inode_mnt); + + d_instantiate(path.dentry, inode); + + file = alloc_file(&path, OPEN_FMODE(flags), fops); + if (IS_ERR(file)) + goto err_dput; + + file->f_mapping = inode->i_mapping; + file->f_flags = flags & (O_ACCMODE | O_NONBLOCK); + file->private_data = priv; + + return file; + +err_dput: + path_put(&path); +err_module: + module_put(fops->owner); + return file; +} +EXPORT_SYMBOL_GPL(anon_inode_getfile_private); + +/** * anon_inode_getfile - creates a new file instance by hooking it up to an * anonymous inode, and a dentry that describe the "class" * of the file diff --git a/include/linux/anon_inodes.h b/include/linux/anon_inodes.h index 8013a45..cf573c2 100644 --- a/include/linux/anon_inodes.h +++ b/include/linux/anon_inodes.h @@ -13,6 +13,9 @@ struct file_operations; struct file *anon_inode_getfile(const char *name, const struct file_operations *fops, void *priv, int flags); +struct file *anon_inode_getfile_private(const char *name, + const struct file_operations *fops, + void *priv, int flags); int anon_inode_getfd(const char *name, const struct file_operations *fops, void *priv, int flags); |