I resurect and refreshed this old patch from https://lists.linux-foundation.org/pipermail/containers/2007-February/003726.html This patch makes automount to work within a container. Make autofs4 container-friendly by caching struct pid reference rather than pid_t and using pid_nr() to retreive a task's pid_t. ChangeLog: V1: - fixed pgrp option in parse_options - used get_task_pid(current, PIDTYPE_PGID) instead of task_pgrp - fixed how is passed the 'pgrp' argument autofs4_fill_super - fixed bad pid conversion, was pid_vnr not pid_nr in autofs4_wait V0: - Refreshed against linux-next (added dev-ioctl.c) - Fix Eric Biederman's comments - Use find_get_pid() to hold a reference to oz_pgrp and release while unmounting; separate out changes to autofs and autofs4. - Also rollback my earlier change to autofs_wait_queue (pid and tgid in the wait queue are just used to write to a userspace daemon's pipe). - Fix Cedric's comments: retain old prototype of parse_options() and move necessary change to its caller. Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxx> Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxx> Cc: Ian Kent <raven@xxxxxxxxxx> Cc: Cedric Le Goater <clg@xxxxxxxxxx> Cc: Dave Hansen <haveblue@xxxxxxxxxx> Cc: Serge E. Hallyn <serge.hallyn@xxxxxxxxxxxxx> Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx> Cc: Helmut Lichtenberg <heli@xxxxxxxxxx> --- fs/autofs4/autofs_i.h | 31 +++++++++++++++++-------------- fs/autofs4/dev-ioctl.c | 32 +++++++++++++++++++------------- fs/autofs4/inode.c | 35 +++++++++++++++++++++++++---------- fs/autofs4/root.c | 3 ++- fs/autofs4/waitq.c | 4 ++-- 5 files changed, 65 insertions(+), 40 deletions(-) diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index 3d283ab..bf2f9b1 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -39,25 +39,25 @@ /* #define DEBUG */ #ifdef DEBUG -#define DPRINTK(fmt, args...) \ -do { \ - printk(KERN_DEBUG "pid %d: %s: " fmt "\n", \ - current->pid, __func__, ##args); \ +#define DPRINTK(fmt, args...) \ +do { \ + printk(KERN_DEBUG "pid %d: %s: " fmt "\n", \ + pid_nr(task_pid(current)), __func__, ##args); \ } while (0) #else #define DPRINTK(fmt, args...) do {} while (0) #endif -#define AUTOFS_WARN(fmt, args...) \ -do { \ - printk(KERN_WARNING "pid %d: %s: " fmt "\n", \ - current->pid, __func__, ##args); \ +#define AUTOFS_WARN(fmt, args...) \ +do { \ + printk(KERN_WARNING "pid %d: %s: " fmt "\n", \ + pid_nr(task_pid(current)), __func__, ##args); \ } while (0) -#define AUTOFS_ERROR(fmt, args...) \ -do { \ - printk(KERN_ERR "pid %d: %s: " fmt "\n", \ - current->pid, __func__, ##args); \ +#define AUTOFS_ERROR(fmt, args...) \ +do { \ + printk(KERN_ERR "pid %d: %s: " fmt "\n", \ + pid_nr(task_pid(current)), __func__, ##args); \ } while (0) /* Unified info structure. This is pointed to by both the dentry and @@ -122,7 +122,7 @@ struct autofs_sb_info { u32 magic; int pipefd; struct file *pipe; - pid_t oz_pgrp; + struct pid *oz_pgrp; int catatonic; int version; int sub_version; @@ -156,7 +156,10 @@ static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry) filesystem without "magic".) */ static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) { - return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp; + struct pid *pgrp = get_task_pid(current, PIDTYPE_PGID); + bool oz_mode = sbi->catatonic || sbi->oz_pgrp == pgrp; + put_pid(pgrp); + return oz_mode; } /* Does a dentry have some pending activity? */ diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index eff9a41..7db3b73 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -360,6 +360,7 @@ static int autofs_dev_ioctl_setpipefd(struct file *fp, { int pipefd; int err = 0; + struct file *pipe; if (param->setpipefd.pipefd == -1) return -EINVAL; @@ -368,22 +369,27 @@ static int autofs_dev_ioctl_setpipefd(struct file *fp, mutex_lock(&sbi->wq_mutex); if (!sbi->catatonic) { - mutex_unlock(&sbi->wq_mutex); - return -EBUSY; - } else { - struct file *pipe = fget(pipefd); - if (!pipe->f_op || !pipe->f_op->write) { - err = -EPIPE; - fput(pipe); - goto out; - } - sbi->oz_pgrp = task_pgrp_nr(current); - sbi->pipefd = pipefd; - sbi->pipe = pipe; - sbi->catatonic = 0; + err = -EBUSY; + goto out; + } + + pipe = fget(pipefd); + if (!pipe->f_op || !pipe->f_op->write) { + err = -EPIPE; + fput(pipe); + goto out; } + + sbi->pipefd = pipefd; + sbi->pipe = pipe; + sbi->catatonic = 0; out: mutex_unlock(&sbi->wq_mutex); + if (!err) { + put_pid(sbi->oz_pgrp); + sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID); + } + return err; } diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c index 821b2b9..01d1515 100644 --- a/fs/autofs4/inode.c +++ b/fs/autofs4/inode.c @@ -112,6 +112,7 @@ void autofs4_kill_sb(struct super_block *sb) /* Free wait queues, close pipe */ autofs4_catatonic_mode(sbi); + put_pid(sbi->oz_pgrp); sb->s_fs_info = NULL; kfree(sbi); @@ -133,7 +134,7 @@ static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt) seq_printf(m, ",uid=%u", root_inode->i_uid); if (root_inode->i_gid != 0) seq_printf(m, ",gid=%u", root_inode->i_gid); - seq_printf(m, ",pgrp=%d", sbi->oz_pgrp); + seq_printf(m, ",pgrp=%d", pid_vnr(sbi->oz_pgrp)); seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ); seq_printf(m, ",minproto=%d", sbi->min_proto); seq_printf(m, ",maxproto=%d", sbi->max_proto); @@ -170,15 +171,16 @@ static const match_table_t tokens = { }; static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, - pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto) + struct pid **oz_pgrp, unsigned int *type, + int *minproto, int *maxproto) { char *p; substring_t args[MAX_OPT_ARGS]; + struct pid *pgrp; int option; *uid = current_uid(); *gid = current_gid(); - *pgrp = task_pgrp_nr(current); *minproto = AUTOFS_MIN_PROTO_VERSION; *maxproto = AUTOFS_MAX_PROTO_VERSION; @@ -212,7 +214,17 @@ static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid, case Opt_pgrp: if (match_int(args, &option)) return 1; - *pgrp = option; + + rcu_read_lock(); + pgrp = find_vpid(option); + if (pgrp) { + put_pid(*oz_pgrp); + *oz_pgrp = get_pid(pgrp); + } + rcu_read_unlock(); + + if (!pgrp) + return 1; break; case Opt_minproto: if (match_int(args, &option)) @@ -275,7 +287,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) sbi->pipe = NULL; sbi->catatonic = 1; sbi->exp_timeout = 0; - sbi->oz_pgrp = task_pgrp_nr(current); + sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID); sbi->sb = s; sbi->version = 0; sbi->sub_version = 0; @@ -299,7 +311,8 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) */ ino = autofs4_mkroot(sbi); if (!ino) - goto fail_free; + goto fail_put_pid; + root_inode = autofs4_get_inode(s, ino); if (!root_inode) goto fail_ino; @@ -342,9 +355,9 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) sbi->version = sbi->max_proto; sbi->sub_version = AUTOFS_PROTO_SUBVERSION; - DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp); + DPRINTK("pipe fd = %d, pgrp = %u", pipefd, pid_nr(sbi->oz_pgrp)); + pipe = fget(pipefd); - if (!pipe) { printk("autofs: could not open pipe file descriptor\n"); goto fail_dput; @@ -370,13 +383,15 @@ fail_fput: /* fall through */ fail_dput: dput(root); - goto fail_free; + goto fail_put_pid; fail_iput: printk("autofs: get root dentry failed\n"); iput(root_inode); fail_ino: kfree(ino); -fail_free: +fail_put_pid: + put_pid(sbi->oz_pgrp); + kfree(sbi); s->s_fs_info = NULL; fail_unlock: diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index d5c1401..45c6bc2 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -541,7 +541,8 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s oz_mode = autofs4_oz_mode(sbi); DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d", - current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode); + pid_nr(task_pid(current)), task_pgrp_nr(current), + sbi->catatonic, oz_mode); active = autofs4_lookup_active(dentry); if (active) { diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index 2341375..e3ce7fe 100644 --- a/fs/autofs4/waitq.c +++ b/fs/autofs4/waitq.c @@ -387,8 +387,8 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry, wq->ino = autofs4_get_ino(sbi); wq->uid = current_uid(); wq->gid = current_gid(); - wq->pid = current->pid; - wq->tgid = current->tgid; + wq->pid = pid_vnr(task_pid(current)); + wq->tgid = pid_vnr(task_tgid(current)); wq->status = -EINTR; /* Status return if interrupted */ wq->wait_ctr = 2; mutex_unlock(&sbi->wq_mutex); -- 1.7.0.4 _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
