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yaml
---
r: 135953
b: refs/heads/master
c: 482984f
h: refs/heads/master
i:
  135951: 5051326
v: v3
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Sukadev Bhattiprolu authored and Al Viro committed Mar 27, 2009
1 parent 95014b3 commit 3b8b2b8
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Showing 2 changed files with 23 additions and 79 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: fdbf5348661ac9d519164d1489f30cc0384fda58
refs/heads/master: 482984f06df54d886995a4383d2f5bb85e3de945
100 changes: 22 additions & 78 deletions trunk/fs/devpts/inode.c
Original file line number Diff line number Diff line change
Expand Up @@ -321,61 +321,22 @@ static int compare_init_pts_sb(struct super_block *s, void *p)
return 0;
}

/*
* Safely parse the mount options in @data and update @opts.
*
* devpts ends up parsing options two times during mount, due to the
* two modes of operation it supports. The first parse occurs in
* devpts_get_sb() when determining the mode (single-instance or
* multi-instance mode). The second parse happens in devpts_remount()
* or new_pts_mount() depending on the mode.
*
* Parsing of options modifies the @data making subsequent parsing
* incorrect. So make a local copy of @data and parse it.
*
* Return: 0 On success, -errno on error
*/
static int safe_parse_mount_options(void *data, struct pts_mount_opts *opts)
{
int rc;
void *datacp;

if (!data)
return 0;

/* Use kstrdup() ? */
datacp = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!datacp)
return -ENOMEM;

memcpy(datacp, data, PAGE_SIZE);
rc = parse_mount_options((char *)datacp, PARSE_MOUNT, opts);
kfree(datacp);

return rc;
}

/*
* Mount a new (private) instance of devpts. PTYs created in this
* instance are independent of the PTYs in other devpts instances.
*/
static int new_pts_mount(struct file_system_type *fs_type, int flags,
void *data, struct vfsmount *mnt)
void *data, struct pts_mount_opts *opts, struct vfsmount *mnt)
{
int err;
struct pts_fs_info *fsi;
struct pts_mount_opts *opts;

err = get_sb_nodev(fs_type, flags, data, devpts_fill_super, mnt);
if (err)
return err;

fsi = DEVPTS_SB(mnt->mnt_sb);
opts = &fsi->mount_opts;

err = parse_mount_options(data, PARSE_MOUNT, opts);
if (err)
goto fail;
memcpy(&fsi->mount_opts, opts, sizeof(opts));

err = mknod_ptmx(mnt->mnt_sb);
if (err)
Expand All @@ -390,28 +351,6 @@ static int new_pts_mount(struct file_system_type *fs_type, int flags,
return err;
}

/*
* Check if 'newinstance' mount option was specified in @data.
*
* Return: -errno on error (eg: invalid mount options specified)
* : 1 if 'newinstance' mount option was specified
* : 0 if 'newinstance' mount option was NOT specified
*/
static int is_new_instance_mount(void *data)
{
int rc;
struct pts_mount_opts opts;

if (!data)
return 0;

rc = safe_parse_mount_options(data, &opts);
if (!rc)
rc = opts.newinstance;

return rc;
}

/*
* get_init_pts_sb()
*
Expand All @@ -434,10 +373,9 @@ static int is_new_instance_mount(void *data)
* presence of the private namespace (i.e 'newinstance') super-blocks.
*/
static int get_init_pts_sb(struct file_system_type *fs_type, int flags,
void *data, struct vfsmount *mnt)
void *data, struct pts_mount_opts *opts, struct vfsmount *mnt)
{
struct super_block *s;
struct pts_mount_opts *opts;
struct pts_fs_info *fsi;
int error;

Expand All @@ -455,11 +393,12 @@ static int get_init_pts_sb(struct file_system_type *fs_type, int flags,
}
s->s_flags |= MS_ACTIVE;
}
fsi = DEVPTS_SB(s);
opts = &fsi->mount_opts;
parse_mount_options(data, PARSE_REMOUNT, opts);

simple_set_mnt(mnt, s);

fsi = DEVPTS_SB(mnt->mnt_sb);
memcpy(&fsi->mount_opts, opts, sizeof(opts));

return 0;
}

Expand All @@ -469,11 +408,11 @@ static int get_init_pts_sb(struct file_system_type *fs_type, int flags,
* kernel still allows multiple-instances.
*/
static int init_pts_mount(struct file_system_type *fs_type, int flags,
void *data, struct vfsmount *mnt)
void *data, struct pts_mount_opts *opts, struct vfsmount *mnt)
{
int err;

err = get_init_pts_sb(fs_type, flags, data, mnt);
err = get_init_pts_sb(fs_type, flags, data, opts, mnt);
if (err)
return err;

Expand All @@ -490,17 +429,22 @@ static int init_pts_mount(struct file_system_type *fs_type, int flags,
static int devpts_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
int new;

new = is_new_instance_mount(data);
if (new < 0)
return new;
int error;
struct pts_mount_opts opts;

if (new)
return new_pts_mount(fs_type, flags, data, mnt);
memset(&opts, 0, sizeof(opts));
if (data) {
error = parse_mount_options(data, PARSE_MOUNT, &opts);
if (error)
return error;
}

return init_pts_mount(fs_type, flags, data, mnt);
if (opts.newinstance)
return new_pts_mount(fs_type, flags, data, &opts, mnt);
else
return init_pts_mount(fs_type, flags, data, &opts, mnt);
}

#else
/*
* This supports only the legacy single-instance semantics (no
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