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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-12 00:13:23 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-12 00:13:23 +0300
commit32fb378437a1d716e72a442237d7ead1f435ecf0 (patch)
tree411b25023d4df908fb8ca4517185d49c37c51e10 /fs/proc
parent19ccb28e296d5afa299db1003d37e5d37994d46e (diff)
parentfceef393a538134f03b778c5d2519e670269342f (diff)
downloadlinux-32fb378437a1d716e72a442237d7ead1f435ecf0.tar.xz
Merge branch 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs RCU symlink updates from Al Viro: "Replacement of ->follow_link/->put_link, allowing to stay in RCU mode even if the symlink is not an embedded one. No changes since the mailbomb on Jan 1" * 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: switch ->get_link() to delayed_call, kill ->put_link() kill free_page_put_link() teach nfs_get_link() to work in RCU mode teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode teach shmem_get_link() to work in RCU mode teach page_get_link() to work in RCU mode replace ->follow_link() with new method that could stay in RCU mode don't put symlink bodies in pagecache into highmem namei: page_getlink() and page_follow_link_light() are the same thing ufs: get rid of ->setattr() for symlinks udf: don't duplicate page_symlink_inode_operations logfs: don't duplicate page_symlink_inode_operations switch befs long symlinks to page_symlink_operations
Diffstat (limited to 'fs/proc')
-rw-r--r--fs/proc/base.c24
-rw-r--r--fs/proc/inode.c21
-rw-r--r--fs/proc/namespaces.c10
-rw-r--r--fs/proc/self.c18
-rw-r--r--fs/proc/thread_self.c19
5 files changed, 54 insertions, 38 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 4bd5d3118acd..55e01f88eac9 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1564,12 +1564,16 @@ static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
return -ENOENT;
}
-static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_pid_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
{
- struct inode *inode = d_inode(dentry);
struct path path;
int error = -EACCES;
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
/* Are we allowed to snoop on the tasks file descriptors? */
if (!proc_fd_access_allowed(inode))
goto out;
@@ -1630,7 +1634,7 @@ out:
const struct inode_operations proc_pid_link_inode_operations = {
.readlink = proc_pid_readlink,
- .follow_link = proc_pid_follow_link,
+ .get_link = proc_pid_get_link,
.setattr = proc_setattr,
};
@@ -1895,7 +1899,7 @@ static const struct dentry_operations tid_map_files_dentry_operations = {
.d_delete = pid_delete_dentry,
};
-static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
+static int map_files_get_link(struct dentry *dentry, struct path *path)
{
unsigned long vm_start, vm_end;
struct vm_area_struct *vma;
@@ -1945,20 +1949,22 @@ struct map_files_info {
* path to the file in question.
*/
static const char *
-proc_map_files_follow_link(struct dentry *dentry, void **cookie)
+proc_map_files_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
{
if (!capable(CAP_SYS_ADMIN))
return ERR_PTR(-EPERM);
- return proc_pid_follow_link(dentry, NULL);
+ return proc_pid_get_link(dentry, inode, done);
}
/*
- * Identical to proc_pid_link_inode_operations except for follow_link()
+ * Identical to proc_pid_link_inode_operations except for get_link()
*/
static const struct inode_operations proc_map_files_link_inode_operations = {
.readlink = proc_pid_readlink,
- .follow_link = proc_map_files_follow_link,
+ .get_link = proc_map_files_get_link,
.setattr = proc_setattr,
};
@@ -1975,7 +1981,7 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
return -ENOENT;
ei = PROC_I(inode);
- ei->op.proc_get_link = proc_map_files_get_link;
+ ei->op.proc_get_link = map_files_get_link;
inode->i_op = &proc_map_files_link_inode_operations;
inode->i_size = 64;
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index bd95b9fdebb0..d0e9b9b6223e 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -393,24 +393,25 @@ static const struct file_operations proc_reg_file_ops_no_compat = {
};
#endif
-static const char *proc_follow_link(struct dentry *dentry, void **cookie)
+static void proc_put_link(void *p)
{
- struct proc_dir_entry *pde = PDE(d_inode(dentry));
- if (unlikely(!use_pde(pde)))
- return ERR_PTR(-EINVAL);
- *cookie = pde;
- return pde->data;
+ unuse_pde(p);
}
-static void proc_put_link(struct inode *unused, void *p)
+static const char *proc_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
{
- unuse_pde(p);
+ struct proc_dir_entry *pde = PDE(inode);
+ if (unlikely(!use_pde(pde)))
+ return ERR_PTR(-EINVAL);
+ set_delayed_call(done, proc_put_link, pde);
+ return pde->data;
}
const struct inode_operations proc_link_inode_operations = {
.readlink = generic_readlink,
- .follow_link = proc_follow_link,
- .put_link = proc_put_link,
+ .get_link = proc_get_link,
};
struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index f6e8354b8cea..1dece8781f91 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -30,14 +30,18 @@ static const struct proc_ns_operations *ns_entries[] = {
&mntns_operations,
};
-static const char *proc_ns_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_ns_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
{
- struct inode *inode = d_inode(dentry);
const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
struct task_struct *task;
struct path ns_path;
void *error = ERR_PTR(-EACCES);
+ if (!dentry)
+ return ERR_PTR(-ECHILD);
+
task = get_proc_task(inode);
if (!task)
return error;
@@ -74,7 +78,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
static const struct inode_operations proc_ns_link_inode_operations = {
.readlink = proc_ns_readlink,
- .follow_link = proc_ns_follow_link,
+ .get_link = proc_ns_get_link,
.setattr = proc_setattr,
};
diff --git a/fs/proc/self.c b/fs/proc/self.c
index 113b8d061fc0..67e8db442cf0 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -18,26 +18,28 @@ static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
return readlink_copy(buffer, buflen, tmp);
}
-static const char *proc_self_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_self_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
{
- struct pid_namespace *ns = dentry->d_sb->s_fs_info;
+ struct pid_namespace *ns = inode->i_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
char *name;
if (!tgid)
return ERR_PTR(-ENOENT);
/* 11 for max length of signed int in decimal + NULL term */
- name = kmalloc(12, GFP_KERNEL);
- if (!name)
- return ERR_PTR(-ENOMEM);
+ name = kmalloc(12, dentry ? GFP_KERNEL : GFP_ATOMIC);
+ if (unlikely(!name))
+ return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
sprintf(name, "%d", tgid);
- return *cookie = name;
+ set_delayed_call(done, kfree_link, name);
+ return name;
}
static const struct inode_operations proc_self_inode_operations = {
.readlink = proc_self_readlink,
- .follow_link = proc_self_follow_link,
- .put_link = kfree_put_link,
+ .get_link = proc_self_get_link,
};
static unsigned self_inum;
diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index 947b0f4fd0a1..9eacd59e0360 100644
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -19,26 +19,29 @@ static int proc_thread_self_readlink(struct dentry *dentry, char __user *buffer,
return readlink_copy(buffer, buflen, tmp);
}
-static const char *proc_thread_self_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_thread_self_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
{
- struct pid_namespace *ns = dentry->d_sb->s_fs_info;
+ struct pid_namespace *ns = inode->i_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
pid_t pid = task_pid_nr_ns(current, ns);
char *name;
if (!pid)
return ERR_PTR(-ENOENT);
- name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
- if (!name)
- return ERR_PTR(-ENOMEM);
+ name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF,
+ dentry ? GFP_KERNEL : GFP_ATOMIC);
+ if (unlikely(!name))
+ return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD);
sprintf(name, "%d/task/%d", tgid, pid);
- return *cookie = name;
+ set_delayed_call(done, kfree_link, name);
+ return name;
}
static const struct inode_operations proc_thread_self_inode_operations = {
.readlink = proc_thread_self_readlink,
- .follow_link = proc_thread_self_follow_link,
- .put_link = kfree_put_link,
+ .get_link = proc_thread_self_get_link,
};
static unsigned thread_self_inum;