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authorRoland Dreier <rdreier@cisco.com>2009-12-18 09:41:24 -0800
committerAl Viro <viro@zeniv.linux.org.uk>2009-12-22 12:27:34 -0500
commit628ff7c1d8d8466a5ad8078bd0206a130f8b8a51 (patch)
treecc7ab0c90849be38e200fc6ff6a3a09e3caf0405 /fs/anon_inodes.c
parented2617585f39dd12fae38c657bba68b9779ea10d (diff)
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anonfd: Allow making anon files read-only
It seems a couple places such as arch/ia64/kernel/perfmon.c and drivers/infiniband/core/uverbs_main.c could use anon_inode_getfile() instead of a private pseudo-fs + alloc_file(), if only there were a way to get a read-only file. So provide this by having anon_inode_getfile() create a read-only file if we pass O_RDONLY in flags. Signed-off-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/anon_inodes.c')
-rw-r--r--fs/anon_inodes.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 2c994591f4d..598237e9722 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -89,11 +89,19 @@ struct file *anon_inode_getfile(const char *name,
struct qstr this;
struct path path;
struct file *file;
+ fmode_t mode;
int error;
if (IS_ERR(anon_inode_inode))
return ERR_PTR(-ENODEV);
+ switch (flags & O_ACCMODE) {
+ case O_RDONLY: mode = FMODE_READ; break;
+ case O_WRONLY: mode = FMODE_WRITE; break;
+ case O_RDWR: mode = FMODE_READ | FMODE_WRITE; break;
+ default: return ERR_PTR(-EINVAL);
+ }
+
if (fops->owner && !try_module_get(fops->owner))
return ERR_PTR(-ENOENT);
@@ -121,13 +129,13 @@ struct file *anon_inode_getfile(const char *name,
d_instantiate(path.dentry, anon_inode_inode);
error = -ENFILE;
- file = alloc_file(&path, FMODE_READ | FMODE_WRITE, fops);
+ file = alloc_file(&path, mode, fops);
if (!file)
goto err_dput;
file->f_mapping = anon_inode_inode->i_mapping;
file->f_pos = 0;
- file->f_flags = O_RDWR | (flags & O_NONBLOCK);
+ file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
file->f_version = 0;
file->private_data = priv;