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Merge branch 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Browse Source 
Pull dcache lookup cleanups from Al Viro:
 "Cleaning ->lookup() instances up - mostly d_splice_alias() conversions"

* 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (29 commits)
  switch the rest of procfs lookups to d_splice_alias()
  procfs: switch instantiate_t to d_splice_alias()
  don't bother with tid_fd_revalidate() in lookups
  proc_lookupfd_common(): don't bother with instantiate unless the file is open
  procfs: get rid of ancient BS in pid_revalidate() uses
  cifs_lookup(): switch to d_splice_alias()
  cifs_lookup(): cifs_get_inode_...() never returns 0 with *inode left NULL
  9p: unify paths in v9fs_vfs_lookup()
  ncp_lookup(): use d_splice_alias()
  hfsplus: switch to d_splice_alias()
  hfs: don't allow mounting over .../rsrc
  hfs: use d_splice_alias()
  omfs_lookup(): report IO errors, use d_splice_alias()
  orangefs_lookup: simplify
  openpromfs: switch to d_splice_alias()
  xfs_vn_lookup: simplify a bit
  adfs_lookup: do not fail with ENOENT on negatives, use d_splice_alias()
  adfs_lookup_byname: .. *is* taken care of in fs/namei.c
  romfs_lookup: switch to d_splice_alias()
  qnx6_lookup: switch to d_splice_alias()
  ...
This commit is contained in:
Linus Torvalds
2018-06-04 13:46:22 -07:00
parent 9214407d12 888e2b03ef
commit b058efc1ac
26 changed files with 293 additions and 451 deletions
Download Patch File Download Diff File Expand all files Collapse all files

136
fs/proc/base.c
View File

@@ -1807,15 +1807,22 @@ int pid_getattr(const struct path *path, struct kstat *stat,
/* dentry stuff */
/*
* Exceptional case: normally we are not allowed to unhash a busy
* directory. In this case, however, we can do it - no aliasing problems
* due to the way we treat inodes.
*
* Set <pid>/... inode ownership (can change due to setuid(), etc.)
*/
void pid_update_inode(struct task_struct *task, struct inode *inode)
{
task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
inode->i_mode &= ~(S_ISUID | S_ISGID);
security_task_to_inode(task, inode);
}
/*
* Rewrite the inode's ownerships here because the owning task may have
* performed a setuid(), etc.
*
*/
int pid_revalidate(struct dentry *dentry, unsigned int flags)
static int pid_revalidate(struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
struct task_struct *task;
@@ -1827,10 +1834,7 @@ int pid_revalidate(struct dentry *dentry, unsigned int flags)
task = get_proc_task(inode);
if (task) {
task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
inode->i_mode &= ~(S_ISUID | S_ISGID);
security_task_to_inode(task, inode);
pid_update_inode(task, inode);
put_task_struct(task);
return 1;
}
@@ -1878,8 +1882,8 @@ bool proc_fill_cache(struct file *file, struct dir_context *ctx,
struct dentry *child, *dir = file->f_path.dentry;
struct qstr qname = QSTR_INIT(name, len);
struct inode *inode;
unsigned type;
ino_t ino;
unsigned type = DT_UNKNOWN;
ino_t ino = 1;
child = d_hash_and_lookup(dir, &qname);
if (!child) {
@@ -1888,22 +1892,23 @@ bool proc_fill_cache(struct file *file, struct dir_context *ctx,
if (IS_ERR(child))
goto end_instantiate;
if (d_in_lookup(child)) {
int err = instantiate(d_inode(dir), child, task, ptr);
struct dentry *res;
res = instantiate(child, task, ptr);
d_lookup_done(child);
if (err < 0) {
dput(child);
if (IS_ERR(res))
goto end_instantiate;
if (unlikely(res)) {
dput(child);
child = res;
}
}
}
inode = d_inode(child);
ino = inode->i_ino;
type = inode->i_mode >> 12;
end_instantiate:
dput(child);
return dir_emit(ctx, name, len, ino, type);
end_instantiate:
return dir_emit(ctx, name, len, 1, DT_UNKNOWN);
}
/*
@@ -2065,19 +2070,19 @@ static const struct inode_operations proc_map_files_link_inode_operations = {
.setattr = proc_setattr,
};
static int
proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
static struct dentry *
proc_map_files_instantiate(struct dentry *dentry,
struct task_struct *task, const void *ptr)
{
fmode_t mode = (fmode_t)(unsigned long)ptr;
struct proc_inode *ei;
struct inode *inode;
inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK |
inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
((mode & FMODE_READ ) ? S_IRUSR : 0) |
((mode & FMODE_WRITE) ? S_IWUSR : 0));
if (!inode)
return -ENOENT;
return ERR_PTR(-ENOENT);
ei = PROC_I(inode);
ei->op.proc_get_link = map_files_get_link;
@@ -2086,9 +2091,7 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
inode->i_size = 64;
d_set_d_op(dentry, &tid_map_files_dentry_operations);
d_add(dentry, inode);
return 0;
return d_splice_alias(inode, dentry);
}
static struct dentry *proc_map_files_lookup(struct inode *dir,
@@ -2097,19 +2100,19 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
unsigned long vm_start, vm_end;
struct vm_area_struct *vma;
struct task_struct *task;
int result;
struct dentry *result;
struct mm_struct *mm;
result = -ENOENT;
result = ERR_PTR(-ENOENT);
task = get_proc_task(dir);
if (!task)
goto out;
result = -EACCES;
result = ERR_PTR(-EACCES);
if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
goto out_put_task;
result = -ENOENT;
result = ERR_PTR(-ENOENT);
if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
goto out_put_task;
@@ -2123,7 +2126,7 @@ static struct dentry *proc_map_files_lookup(struct inode *dir,
goto out_no_vma;
if (vma->vm_file)
result = proc_map_files_instantiate(dir, dentry, task,
result = proc_map_files_instantiate(dentry, task,
(void *)(unsigned long)vma->vm_file->f_mode);
out_no_vma:
@@ -2132,7 +2135,7 @@ out_no_vma:
out_put_task:
put_task_struct(task);
out:
return ERR_PTR(result);
return result;
}
static const struct inode_operations proc_map_files_inode_operations = {
@@ -2433,16 +2436,16 @@ static const struct file_operations proc_pid_set_timerslack_ns_operations = {
.release = single_release,
};
static int proc_pident_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, const void *ptr)
static struct dentry *proc_pident_instantiate(struct dentry *dentry,
struct task_struct *task, const void *ptr)
{
const struct pid_entry *p = ptr;
struct inode *inode;
struct proc_inode *ei;
inode = proc_pid_make_inode(dir->i_sb, task, p->mode);
inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
if (!inode)
goto out;
return ERR_PTR(-ENOENT);
ei = PROC_I(inode);
if (S_ISDIR(inode->i_mode))
@@ -2452,13 +2455,9 @@ static int proc_pident_instantiate(struct inode *dir,
if (p->fop)
inode->i_fop = p->fop;
ei->op = p->op;
pid_update_inode(task, inode);
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, 0))
return 0;
out:
return -ENOENT;
return d_splice_alias(inode, dentry);
}
static struct dentry *proc_pident_lookup(struct inode *dir,
@@ -2466,11 +2465,9 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
const struct pid_entry *ents,
unsigned int nents)
{
int error;
struct task_struct *task = get_proc_task(dir);
const struct pid_entry *p, *last;
error = -ENOENT;
struct dentry *res = ERR_PTR(-ENOENT);
if (!task)
goto out_no_task;
@@ -2489,11 +2486,11 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
if (p >= last)
goto out;
error = proc_pident_instantiate(dir, dentry, task, p);
res = proc_pident_instantiate(dentry, task, p);
out:
put_task_struct(task);
out_no_task:
return ERR_PTR(error);
return res;
}
static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
@@ -3136,38 +3133,32 @@ void proc_flush_task(struct task_struct *task)
}
}
static int proc_pid_instantiate(struct inode *dir,
struct dentry * dentry,
static struct dentry *proc_pid_instantiate(struct dentry * dentry,
struct task_struct *task, const void *ptr)
{
struct inode *inode;
inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
if (!inode)
goto out;
return ERR_PTR(-ENOENT);
inode->i_op = &proc_tgid_base_inode_operations;
inode->i_fop = &proc_tgid_base_operations;
inode->i_flags|=S_IMMUTABLE;
set_nlink(inode, nlink_tgid);
pid_update_inode(task, inode);
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, 0))
return 0;
out:
return -ENOENT;
return d_splice_alias(inode, dentry);
}
struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
{
int result = -ENOENT;
struct task_struct *task;
unsigned tgid;
struct pid_namespace *ns;
struct dentry *result = ERR_PTR(-ENOENT);
tgid = name_to_int(&dentry->d_name);
if (tgid == ~0U)
@@ -3182,10 +3173,10 @@ struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsign
if (!task)
goto out;
result = proc_pid_instantiate(dir, dentry, task, NULL);
result = proc_pid_instantiate(dentry, task, NULL);
put_task_struct(task);
out:
return ERR_PTR(result);
return result;
}
/*
@@ -3433,37 +3424,32 @@ static const struct inode_operations proc_tid_base_inode_operations = {
.setattr = proc_setattr,
};
static int proc_task_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, const void *ptr)
static struct dentry *proc_task_instantiate(struct dentry *dentry,
struct task_struct *task, const void *ptr)
{
struct inode *inode;
inode = proc_pid_make_inode(dir->i_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
if (!inode)
goto out;
return ERR_PTR(-ENOENT);
inode->i_op = &proc_tid_base_inode_operations;
inode->i_fop = &proc_tid_base_operations;
inode->i_flags|=S_IMMUTABLE;
inode->i_flags |= S_IMMUTABLE;
set_nlink(inode, nlink_tid);
pid_update_inode(task, inode);
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, 0))
return 0;
out:
return -ENOENT;
return d_splice_alias(inode, dentry);
}
static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
{
int result = -ENOENT;
struct task_struct *task;
struct task_struct *leader = get_proc_task(dir);
unsigned tid;
struct pid_namespace *ns;
struct dentry *result = ERR_PTR(-ENOENT);
if (!leader)
goto out_no_task;
@@ -3483,13 +3469,13 @@ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry
if (!same_thread_group(leader, task))
goto out_drop_task;
result = proc_task_instantiate(dir, dentry, task, NULL);
result = proc_task_instantiate(dentry, task, NULL);
out_drop_task:
put_task_struct(task);
out:
put_task_struct(leader);
out_no_task:
return ERR_PTR(result);
return result;
}
/*

138
fs/proc/fd.c
View File

@@ -81,9 +81,41 @@ static const struct file_operations proc_fdinfo_file_operations = {
.release = single_release,
};
static bool tid_fd_mode(struct task_struct *task, unsigned fd, fmode_t *mode)
{
struct files_struct *files = get_files_struct(task);
struct file *file;
if (!files)
return false;
rcu_read_lock();
file = fcheck_files(files, fd);
if (file)
*mode = file->f_mode;
rcu_read_unlock();
put_files_struct(files);
return !!file;
}
static void tid_fd_update_inode(struct task_struct *task, struct inode *inode,
fmode_t f_mode)
{
task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
if (S_ISLNK(inode->i_mode)) {
unsigned i_mode = S_IFLNK;
if (f_mode & FMODE_READ)
i_mode |= S_IRUSR | S_IXUSR;
if (f_mode & FMODE_WRITE)
i_mode |= S_IWUSR | S_IXUSR;
inode->i_mode = i_mode;
}
security_task_to_inode(task, inode);
}
static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
{
struct files_struct *files;
struct task_struct *task;
struct inode *inode;
unsigned int fd;
@@ -96,35 +128,11 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
fd = proc_fd(inode);
if (task) {
files = get_files_struct(task);
if (files) {
struct file *file;
rcu_read_lock();
file = fcheck_files(files, fd);
if (file) {
unsigned f_mode = file->f_mode;
rcu_read_unlock();
put_files_struct(files);
task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
if (S_ISLNK(inode->i_mode)) {
unsigned i_mode = S_IFLNK;
if (f_mode & FMODE_READ)
i_mode |= S_IRUSR | S_IXUSR;
if (f_mode & FMODE_WRITE)
i_mode |= S_IWUSR | S_IXUSR;
inode->i_mode = i_mode;
}
security_task_to_inode(task, inode);
put_task_struct(task);
return 1;
}
rcu_read_unlock();
put_files_struct(files);
fmode_t f_mode;
if (tid_fd_mode(task, fd, &f_mode)) {
tid_fd_update_inode(task, inode, f_mode);
put_task_struct(task);
return 1;
}
put_task_struct(task);
}
@@ -166,34 +174,33 @@ static int proc_fd_link(struct dentry *dentry, struct path *path)
return ret;
}
static int
proc_fd_instantiate(struct inode *dir, struct dentry *dentry,
struct task_struct *task, const void *ptr)
struct fd_data {
fmode_t mode;
unsigned fd;
};
static struct dentry *proc_fd_instantiate(struct dentry *dentry,
struct task_struct *task, const void *ptr)
{
unsigned fd = (unsigned long)ptr;
const struct fd_data *data = ptr;
struct proc_inode *ei;
struct inode *inode;
inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK);
inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK);
if (!inode)
goto out;
return ERR_PTR(-ENOENT);
ei = PROC_I(inode);
ei->fd = fd;
ei->fd = data->fd;
inode->i_op = &proc_pid_link_inode_operations;
inode->i_size = 64;
ei->op.proc_get_link = proc_fd_link;
tid_fd_update_inode(task, inode, data->mode);
d_set_d_op(dentry, &tid_fd_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (tid_fd_revalidate(dentry, 0))
return 0;
out:
return -ENOENT;
return d_splice_alias(inode, dentry);
}
static struct dentry *proc_lookupfd_common(struct inode *dir,
@@ -201,19 +208,21 @@ static struct dentry *proc_lookupfd_common(struct inode *dir,
instantiate_t instantiate)
{
struct task_struct *task = get_proc_task(dir);
int result = -ENOENT;
unsigned fd = name_to_int(&dentry->d_name);
struct fd_data data = {.fd = name_to_int(&dentry->d_name)};
struct dentry *result = ERR_PTR(-ENOENT);
if (!task)
goto out_no_task;
if (fd == ~0U)
if (data.fd == ~0U)
goto out;
if (!tid_fd_mode(task, data.fd, &data.mode))
goto out;
result = instantiate(dir, dentry, task, (void *)(unsigned long)fd);
result = instantiate(dentry, task, &data);
out:
put_task_struct(task);
out_no_task:
return ERR_PTR(result);
return result;
}
static int proc_readfd_common(struct file *file, struct dir_context *ctx,
@@ -236,17 +245,22 @@ static int proc_readfd_common(struct file *file, struct dir_context *ctx,
for (fd = ctx->pos - 2;
fd < files_fdtable(files)->max_fds;
fd++, ctx->pos++) {
struct file *f;
struct fd_data data;
char name[10 + 1];
int len;
if (!fcheck_files(files, fd))
f = fcheck_files(files, fd);
if (!f)
continue;
data.mode = f->f_mode;
rcu_read_unlock();
data.fd = fd;
len = snprintf(name, sizeof(name), "%u", fd);
if (!proc_fill_cache(file, ctx,
name, len, instantiate, p,
(void *)(unsigned long)fd))
&data))
goto out_fd_loop;
cond_resched();
rcu_read_lock();
@@ -304,31 +318,25 @@ const struct inode_operations proc_fd_inode_operations = {
.setattr = proc_setattr,
};
static int
proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry,
struct task_struct *task, const void *ptr)
static struct dentry *proc_fdinfo_instantiate(struct dentry *dentry,
struct task_struct *task, const void *ptr)
{
unsigned fd = (unsigned long)ptr;
const struct fd_data *data = ptr;
struct proc_inode *ei;
struct inode *inode;
inode = proc_pid_make_inode(dir->i_sb, task, S_IFREG | S_IRUSR);
inode = proc_pid_make_inode(dentry->d_sb, task, S_IFREG | S_IRUSR);
if (!inode)
goto out;
return ERR_PTR(-ENOENT);
ei = PROC_I(inode);
ei->fd = fd;
ei->fd = data->fd;
inode->i_fop = &proc_fdinfo_file_operations;
tid_fd_update_inode(task, inode, 0);
d_set_d_op(dentry, &tid_fd_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (tid_fd_revalidate(dentry, 0))
return 0;
out:
return -ENOENT;
return d_splice_alias(inode, dentry);
}
static struct dentry *

3
fs/proc/generic.c
View File

@@ -257,8 +257,7 @@ struct dentry *proc_lookup_de(struct inode *dir, struct dentry *dentry,
if (!inode)
return ERR_PTR(-ENOMEM);
d_set_d_op(dentry, &proc_misc_dentry_ops);
d_add(dentry, inode);
return NULL;
return d_splice_alias(inode, dentry);
}
read_unlock(&proc_subdir_lock);
return ERR_PTR(-ENOENT);

4
fs/proc/internal.h
View File

@@ -152,14 +152,14 @@ extern const struct dentry_operations pid_dentry_operations;
extern int pid_getattr(const struct path *, struct kstat *, u32, unsigned int);
extern int proc_setattr(struct dentry *, struct iattr *);
extern struct inode *proc_pid_make_inode(struct super_block *, struct task_struct *, umode_t);
extern int pid_revalidate(struct dentry *, unsigned int);
extern void pid_update_inode(struct task_struct *, struct inode *);
extern int pid_delete_dentry(const struct dentry *);
extern int proc_pid_readdir(struct file *, struct dir_context *);
extern struct dentry *proc_pid_lookup(struct inode *, struct dentry *, unsigned int);
extern loff_t mem_lseek(struct file *, loff_t, int);
/* Lookups */
typedef int instantiate_t(struct inode *, struct dentry *,
typedef struct dentry *instantiate_t(struct dentry *,
struct task_struct *, const void *);
extern bool proc_fill_cache(struct file *, struct dir_context *, const char *, int,
instantiate_t, struct task_struct *, const void *);

24
fs/proc/namespaces.c
View File

@@ -87,28 +87,24 @@ static const struct inode_operations proc_ns_link_inode_operations = {
.setattr = proc_setattr,
};
static int proc_ns_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, const void *ptr)
static struct dentry *proc_ns_instantiate(struct dentry *dentry,
struct task_struct *task, const void *ptr)
{
const struct proc_ns_operations *ns_ops = ptr;
struct inode *inode;
struct proc_inode *ei;
inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK | S_IRWXUGO);
inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | S_IRWXUGO);
if (!inode)
goto out;
return ERR_PTR(-ENOENT);
ei = PROC_I(inode);
inode->i_op = &proc_ns_link_inode_operations;
ei->ns_ops = ns_ops;
pid_update_inode(task, inode);
d_set_d_op(dentry, &pid_dentry_operations);
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, 0))
return 0;
out:
return -ENOENT;
return d_splice_alias(inode, dentry);
}
static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
@@ -147,12 +143,10 @@ const struct file_operations proc_ns_dir_operations = {
static struct dentry *proc_ns_dir_lookup(struct inode *dir,
struct dentry *dentry, unsigned int flags)
{
int error;
struct task_struct *task = get_proc_task(dir);
const struct proc_ns_operations **entry, **last;
unsigned int len = dentry->d_name.len;
error = -ENOENT;
struct dentry *res = ERR_PTR(-ENOENT);
if (!task)
goto out_no_task;
@@ -167,11 +161,11 @@ static struct dentry *proc_ns_dir_lookup(struct inode *dir,
if (entry == last)
goto out;
error = proc_ns_instantiate(dir, dentry, task, *entry);
res = proc_ns_instantiate(dentry, task, *entry);
out:
put_task_struct(task);
out_no_task:
return ERR_PTR(error);
return res;
}
const struct inode_operations proc_ns_dir_inode_operations = {

15
fs/proc/proc_sysctl.c
View File

@@ -554,9 +554,8 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
if (!inode)
goto out;
err = NULL;
d_set_d_op(dentry, &proc_sys_dentry_operations);
d_add(dentry, inode);
err = d_splice_alias(inode, dentry);
out:
if (h)
@@ -684,6 +683,7 @@ static bool proc_sys_fill_cache(struct file *file,
if (IS_ERR(child))
return false;
if (d_in_lookup(child)) {
struct dentry *res;
inode = proc_sys_make_inode(dir->d_sb, head, table);
if (!inode) {
d_lookup_done(child);
@@ -691,7 +691,16 @@ static bool proc_sys_fill_cache(struct file *file,
return false;
}
d_set_d_op(child, &proc_sys_dentry_operations);
d_add(child, inode);
res = d_splice_alias(inode, child);
d_lookup_done(child);
if (unlikely(res)) {
if (IS_ERR(res)) {
dput(child);
return false;
}
dput(child);
child = res;
}
}
}
inode = d_inode(child);