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[PATCH] proc: Factor out an instantiate method from every lookup method
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To remove the hard coded proc inode numbers it is necessary to be able to
create the proc inodes during readdir.  The instantiate methods are the subset
of lookup that is needed to accomplish that.

This first step just splits the lookup methods into 2 functions.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Eric W. Biederman authored and Linus Torvalds committed Oct 2, 2006
1 parent 801199c commit 444ceed
Showing 1 changed file with 158 additions and 111 deletions.
269 changes: 158 additions & 111 deletions fs/proc/base.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1254,21 +1254,15 @@ static struct dentry_operations tid_fd_dentry_operations =
.d_delete = pid_delete_dentry,
};

/* SMP-safe */
static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
static struct dentry *proc_fd_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, void *ptr)
{
struct task_struct *task = get_proc_task(dir);
unsigned fd = name_to_int(dentry);
struct dentry *result = ERR_PTR(-ENOENT);
struct file * file;
struct files_struct * files;
struct inode *inode;
struct proc_inode *ei;

if (!task)
goto out_no_task;
if (fd == ~0U)
goto out;
unsigned fd = *(unsigned *)ptr;
struct file *file;
struct files_struct *files;
struct inode *inode;
struct proc_inode *ei;
struct dentry *error = ERR_PTR(-ENOENT);

inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_FD_DIR+fd);
if (!inode)
Expand All @@ -1277,7 +1271,7 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
ei->fd = fd;
files = get_files_struct(task);
if (!files)
goto out_unlock;
goto out_iput;
inode->i_mode = S_IFLNK;

/*
Expand All @@ -1287,34 +1281,52 @@ static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry,
spin_lock(&files->file_lock);
file = fcheck_files(files, fd);
if (!file)
goto out_unlock2;
goto out_unlock;
if (file->f_mode & 1)
inode->i_mode |= S_IRUSR | S_IXUSR;
if (file->f_mode & 2)
inode->i_mode |= S_IWUSR | S_IXUSR;
spin_unlock(&files->file_lock);
put_files_struct(files);

inode->i_op = &proc_pid_link_inode_operations;
inode->i_size = 64;
ei->op.proc_get_link = proc_fd_link;
dentry->d_op = &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, NULL))
result = NULL;
out:
put_task_struct(task);
out_no_task:
return result;
error = NULL;

out_unlock2:
out:
return error;
out_unlock:
spin_unlock(&files->file_lock);
put_files_struct(files);
out_unlock:
out_iput:
iput(inode);
goto out;
}

/* SMP-safe */
static struct dentry *proc_lookupfd(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
{
struct task_struct *task = get_proc_task(dir);
unsigned fd = name_to_int(dentry);
struct dentry *result = ERR_PTR(-ENOENT);

if (!task)
goto out_no_task;
if (fd == ~0U)
goto out;

result = proc_fd_instantiate(dir, dentry, task, &fd);
out:
put_task_struct(task);
out_no_task:
return result;
}

static int proc_readfd(struct file * filp, void * dirent, filldir_t filldir)
{
struct dentry *dentry = filp->f_dentry;
Expand Down Expand Up @@ -1395,6 +1407,36 @@ static struct inode_operations proc_fd_inode_operations = {
.setattr = proc_setattr,
};

static struct dentry *proc_pident_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, void *ptr)
{
struct pid_entry *p = ptr;
struct inode *inode;
struct proc_inode *ei;
struct dentry *error = ERR_PTR(-EINVAL);

inode = proc_pid_make_inode(dir->i_sb, task, p->type);
if (!inode)
goto out;

ei = PROC_I(inode);
inode->i_mode = p->mode;
if (S_ISDIR(inode->i_mode))
inode->i_nlink = 2; /* Use getattr to fix if necessary */
if (p->iop)
inode->i_op = p->iop;
if (p->fop)
inode->i_fop = p->fop;
ei->op = p->op;
dentry->d_op = &pid_dentry_operations;
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
error = NULL;
out:
return error;
}

/* SMP-safe */
static struct dentry *proc_pident_lookup(struct inode *dir,
struct dentry *dentry,
Expand All @@ -1404,7 +1446,6 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
struct pid_entry *p;
struct proc_inode *ei;

error = ERR_PTR(-ENOENT);
inode = NULL;
Expand All @@ -1425,25 +1466,7 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
if (!p->name)
goto out;

error = ERR_PTR(-EINVAL);
inode = proc_pid_make_inode(dir->i_sb, task, p->type);
if (!inode)
goto out;

ei = PROC_I(inode);
inode->i_mode = p->mode;
if (S_ISDIR(inode->i_mode))
inode->i_nlink = 2; /* Use getattr to fix if necessary */
if (p->iop)
inode->i_op = p->iop;
if (p->fop)
inode->i_fop = p->fop;
ei->op = p->op;
dentry->d_op = &pid_dentry_operations;
d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
error = NULL;
error = proc_pident_instantiate(dir, dentry, task, p);
out:
put_task_struct(task);
out_no_task:
Expand Down Expand Up @@ -1709,29 +1732,13 @@ static struct dentry_operations proc_base_dentry_operations =
.d_delete = pid_delete_dentry,
};

static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
static struct dentry *proc_base_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, void *ptr)
{
struct pid_entry *p = ptr;
struct inode *inode;
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
struct pid_entry *p;
struct proc_inode *ei;

error = ERR_PTR(-ENOENT);
inode = NULL;

if (!task)
goto out_no_task;

/* Lookup the directory entry */
for (p = proc_base_stuff; p->name; p++) {
if (p->len != dentry->d_name.len)
continue;
if (!memcmp(dentry->d_name.name, p->name, p->len))
break;
}
if (!p->name)
goto out;
struct dentry *error = ERR_PTR(-EINVAL);

/* Allocate the inode */
error = ERR_PTR(-ENOMEM);
Expand Down Expand Up @@ -1767,14 +1774,41 @@ static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
d_add(dentry, inode);
error = NULL;
out:
put_task_struct(task);
out_no_task:
return error;
out_iput:
iput(inode);
goto out;
}

static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
{
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
struct pid_entry *p;

error = ERR_PTR(-ENOENT);

if (!task)
goto out_no_task;

/* Lookup the directory entry */
for (p = proc_base_stuff; p->name; p++) {
if (p->len != dentry->d_name.len)
continue;
if (!memcmp(dentry->d_name.name, p->name, p->len))
break;
}
if (!p->name)
goto out;

error = proc_base_instantiate(dir, dentry, task, p);

out:
put_task_struct(task);
out_no_task:
return error;
}

/*
* Thread groups
*/
Expand Down Expand Up @@ -1915,12 +1949,40 @@ void proc_flush_task(struct task_struct *task)
return;
}

struct dentry *proc_pid_instantiate(struct inode *dir,
struct dentry * dentry, struct task_struct *task, void *ptr)
{
struct dentry *error = ERR_PTR(-ENOENT);
struct inode *inode;

inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);
if (!inode)
goto out;

inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
inode->i_op = &proc_tgid_base_inode_operations;
inode->i_fop = &proc_tgid_base_operations;
inode->i_flags|=S_IMMUTABLE;
inode->i_nlink = 4;
#ifdef CONFIG_SECURITY
inode->i_nlink += 1;
#endif

dentry->d_op = &pid_dentry_operations;

d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
error = NULL;
out:
return error;
}

/* SMP-safe */
struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
{
struct dentry *result = ERR_PTR(-ENOENT);
struct task_struct *task;
struct inode *inode;
unsigned tgid;

result = proc_base_lookup(dir, dentry);
Expand All @@ -1939,28 +2001,7 @@ struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct
if (!task)
goto out;

inode = proc_pid_make_inode(dir->i_sb, task, PROC_TGID_INO);
if (!inode)
goto out_put_task;

inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
inode->i_op = &proc_tgid_base_inode_operations;
inode->i_fop = &proc_tgid_base_operations;
inode->i_flags|=S_IMMUTABLE;
#ifdef CONFIG_SECURITY
inode->i_nlink = 5;
#else
inode->i_nlink = 4;
#endif

dentry->d_op = &pid_dentry_operations;

d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
result = NULL;

out_put_task:
result = proc_pid_instantiate(dir, dentry, task, NULL);
put_task_struct(task);
out:
return result;
Expand Down Expand Up @@ -2107,13 +2148,40 @@ static struct inode_operations proc_tid_base_inode_operations = {
.setattr = proc_setattr,
};

static struct dentry *proc_task_instantiate(struct inode *dir,
struct dentry *dentry, struct task_struct *task, void *ptr)
{
struct dentry *error = ERR_PTR(-ENOENT);
struct inode *inode;
inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO);

if (!inode)
goto out;
inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
inode->i_op = &proc_tid_base_inode_operations;
inode->i_fop = &proc_tid_base_operations;
inode->i_flags|=S_IMMUTABLE;
inode->i_nlink = 3;
#ifdef CONFIG_SECURITY
inode->i_nlink += 1;
#endif

dentry->d_op = &pid_dentry_operations;

d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
error = NULL;
out:
return error;
}

/* SMP-safe */
static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
{
struct dentry *result = ERR_PTR(-ENOENT);
struct task_struct *task;
struct task_struct *leader = get_proc_task(dir);
struct inode *inode;
unsigned tid;

if (!leader)
Expand All @@ -2133,28 +2201,7 @@ static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry
if (leader->tgid != task->tgid)
goto out_drop_task;

inode = proc_pid_make_inode(dir->i_sb, task, PROC_TID_INO);


if (!inode)
goto out_drop_task;
inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
inode->i_op = &proc_tid_base_inode_operations;
inode->i_fop = &proc_tid_base_operations;
inode->i_flags|=S_IMMUTABLE;
#ifdef CONFIG_SECURITY
inode->i_nlink = 4;
#else
inode->i_nlink = 3;
#endif

dentry->d_op = &pid_dentry_operations;

d_add(dentry, inode);
/* Close the race of the process dying before we return the dentry */
if (pid_revalidate(dentry, NULL))
result = NULL;

result = proc_task_instantiate(dir, dentry, task, NULL);
out_drop_task:
put_task_struct(task);
out:
Expand Down

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