diff options
| -rw-r--r-- | fs/Kconfig | 7 | ||||
| -rw-r--r-- | fs/internal.h | 6 | ||||
| -rw-r--r-- | fs/libfs.c | 33 | ||||
| -rw-r--r-- | fs/nsfs.c | 11 | ||||
| -rw-r--r-- | fs/pidfs.c | 101 | ||||
| -rw-r--r-- | include/linux/pid.h | 6 | ||||
| -rw-r--r-- | include/linux/pidfs.h | 1 | ||||
| -rw-r--r-- | kernel/pid.c | 6 |
8 files changed, 78 insertions, 93 deletions
diff --git a/fs/Kconfig b/fs/Kconfig index 4bc7dd420874..ea2f77446080 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -173,13 +173,6 @@ source "fs/proc/Kconfig" source "fs/kernfs/Kconfig" source "fs/sysfs/Kconfig" -config FS_PID - bool "Pseudo filesystem for process file descriptors" - depends on 64BIT - default y - help - Pidfs implements advanced features for process file descriptors. - config TMPFS bool "Tmpfs virtual memory file system support (former shm fs)" depends on SHMEM diff --git a/fs/internal.h b/fs/internal.h index 49c1fcfee4b3..7ca738904e34 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -313,8 +313,8 @@ struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap); void mnt_idmap_put(struct mnt_idmap *idmap); struct stashed_operations { void (*put_data)(void *data); - void (*init_inode)(struct inode *inode, void *data); + int (*init_inode)(struct inode *inode, void *data); }; -int path_from_stashed(struct dentry **stashed, unsigned long ino, - struct vfsmount *mnt, void *data, struct path *path); +int path_from_stashed(struct dentry **stashed, struct vfsmount *mnt, void *data, + struct path *path); void stashed_dentry_prune(struct dentry *dentry); diff --git a/fs/libfs.c b/fs/libfs.c index 0d14ae808fcf..3a6f2cb364f8 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -2001,34 +2001,40 @@ static inline struct dentry *get_stashed_dentry(struct dentry *stashed) } static struct dentry *prepare_anon_dentry(struct dentry **stashed, - unsigned long ino, struct super_block *sb, void *data) { struct dentry *dentry; struct inode *inode; const struct stashed_operations *sops = sb->s_fs_info; - - dentry = d_alloc_anon(sb); - if (!dentry) - return ERR_PTR(-ENOMEM); + int ret; inode = new_inode_pseudo(sb); if (!inode) { - dput(dentry); + sops->put_data(data); return ERR_PTR(-ENOMEM); } - inode->i_ino = ino; inode->i_flags |= S_IMMUTABLE; inode->i_mode = S_IFREG; simple_inode_init_ts(inode); - sops->init_inode(inode, data); + + ret = sops->init_inode(inode, data); + if (ret < 0) { + iput(inode); + return ERR_PTR(ret); + } /* Notice when this is changed. */ WARN_ON_ONCE(!S_ISREG(inode->i_mode)); WARN_ON_ONCE(!IS_IMMUTABLE(inode)); + dentry = d_alloc_anon(sb); + if (!dentry) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + /* Store address of location where dentry's supposed to be stashed. */ dentry->d_fsdata = stashed; @@ -2062,7 +2068,6 @@ static struct dentry *stash_dentry(struct dentry **stashed, /** * path_from_stashed - create path from stashed or new dentry * @stashed: where to retrieve or stash dentry - * @ino: inode number to use * @mnt: mnt of the filesystems to use * @data: data to store in inode->i_private * @path: path to create @@ -2077,8 +2082,8 @@ static struct dentry *stash_dentry(struct dentry **stashed, * * Return: On success zero and on failure a negative error is returned. */ -int path_from_stashed(struct dentry **stashed, unsigned long ino, - struct vfsmount *mnt, void *data, struct path *path) +int path_from_stashed(struct dentry **stashed, struct vfsmount *mnt, void *data, + struct path *path) { struct dentry *dentry; const struct stashed_operations *sops = mnt->mnt_sb->s_fs_info; @@ -2091,11 +2096,9 @@ int path_from_stashed(struct dentry **stashed, unsigned long ino, } /* Allocate a new dentry. */ - dentry = prepare_anon_dentry(stashed, ino, mnt->mnt_sb, data); - if (IS_ERR(dentry)) { - sops->put_data(data); + dentry = prepare_anon_dentry(stashed, mnt->mnt_sb, data); + if (IS_ERR(dentry)) return PTR_ERR(dentry); - } /* Added a new dentry. @data is now owned by the filesystem. */ path->dentry = stash_dentry(stashed, dentry); diff --git a/fs/nsfs.c b/fs/nsfs.c index 7aaafb5cb9fc..07e22a15ef02 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -56,7 +56,7 @@ int ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb, if (!ns) return -ENOENT; - return path_from_stashed(&ns->stashed, ns->inum, nsfs_mnt, ns, path); + return path_from_stashed(&ns->stashed, nsfs_mnt, ns, path); } struct ns_get_path_task_args { @@ -101,8 +101,7 @@ int open_related_ns(struct ns_common *ns, return PTR_ERR(relative); } - err = path_from_stashed(&relative->stashed, relative->inum, nsfs_mnt, - relative, &path); + err = path_from_stashed(&relative->stashed, nsfs_mnt, relative, &path); if (err < 0) { put_unused_fd(fd); return err; @@ -199,11 +198,15 @@ static const struct super_operations nsfs_ops = { .show_path = nsfs_show_path, }; -static void nsfs_init_inode(struct inode *inode, void *data) +static int nsfs_init_inode(struct inode *inode, void *data) { + struct ns_common *ns = data; + inode->i_private = data; inode->i_mode |= S_IRUGO; inode->i_fop = &ns_file_operations; + inode->i_ino = ns->inum; + return 0; } static void nsfs_put_data(void *data) diff --git a/fs/pidfs.c b/fs/pidfs.c index 8fd71a00be9c..a63d5d24aa02 100644 --- a/fs/pidfs.c +++ b/fs/pidfs.c @@ -16,17 +16,6 @@ #include "internal.h" -static int pidfd_release(struct inode *inode, struct file *file) -{ -#ifndef CONFIG_FS_PID - struct pid *pid = file->private_data; - - file->private_data = NULL; - put_pid(pid); -#endif - return 0; -} - #ifdef CONFIG_PROC_FS /** * pidfd_show_fdinfo - print information about a pidfd @@ -120,7 +109,6 @@ static __poll_t pidfd_poll(struct file *file, struct poll_table_struct *pts) } static const struct file_operations pidfs_file_operations = { - .release = pidfd_release, .poll = pidfd_poll, #ifdef CONFIG_PROC_FS .show_fdinfo = pidfd_show_fdinfo, @@ -131,16 +119,45 @@ struct pid *pidfd_pid(const struct file *file) { if (file->f_op != &pidfs_file_operations) return ERR_PTR(-EBADF); -#ifdef CONFIG_FS_PID return file_inode(file)->i_private; -#else - return file->private_data; -#endif } -#ifdef CONFIG_FS_PID static struct vfsmount *pidfs_mnt __ro_after_init; +#if BITS_PER_LONG == 32 +/* + * Provide a fallback mechanism for 32-bit systems so processes remain + * reliably comparable by inode number even on those systems. + */ +static DEFINE_IDA(pidfd_inum_ida); + +static int pidfs_inum(struct pid *pid, unsigned long *ino) +{ + int ret; + + ret = ida_alloc_range(&pidfd_inum_ida, RESERVED_PIDS + 1, + UINT_MAX, GFP_ATOMIC); + if (ret < 0) + return -ENOSPC; + + *ino = ret; + return 0; +} + +static inline void pidfs_free_inum(unsigned long ino) +{ + if (ino > 0) + ida_free(&pidfd_inum_ida, ino); +} +#else +static inline int pidfs_inum(struct pid *pid, unsigned long *ino) +{ + *ino = pid->ino; + return 0; +} +#define pidfs_free_inum(ino) ((void)(ino)) +#endif + /* * The vfs falls back to simple_setattr() if i_op->setattr() isn't * implemented. Let's reject it completely until we have a clean @@ -173,6 +190,7 @@ static void pidfs_evict_inode(struct inode *inode) clear_inode(inode); put_pid(pid); + pidfs_free_inum(inode->i_ino); } static const struct super_operations pidfs_sops = { @@ -183,8 +201,10 @@ static const struct super_operations pidfs_sops = { static char *pidfs_dname(struct dentry *dentry, char *buffer, int buflen) { - return dynamic_dname(buffer, buflen, "pidfd:[%lu]", - d_inode(dentry)->i_ino); + struct inode *inode = d_inode(dentry); + struct pid *pid = inode->i_private; + + return dynamic_dname(buffer, buflen, "pidfd:[%llu]", pid->ino); } static const struct dentry_operations pidfs_dentry_operations = { @@ -193,13 +213,19 @@ static const struct dentry_operations pidfs_dentry_operations = { .d_prune = stashed_dentry_prune, }; -static void pidfs_init_inode(struct inode *inode, void *data) +static int pidfs_init_inode(struct inode *inode, void *data) { inode->i_private = data; inode->i_flags |= S_PRIVATE; inode->i_mode |= S_IRWXU; inode->i_op = &pidfs_inode_operations; inode->i_fop = &pidfs_file_operations; + /* + * Inode numbering for pidfs start at RESERVED_PIDS + 1. This + * avoids collisions with the root inode which is 1 for pseudo + * filesystems. + */ + return pidfs_inum(data, &inode->i_ino); } static void pidfs_put_data(void *data) @@ -240,13 +266,7 @@ struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags) struct path path; int ret; - /* - * Inode numbering for pidfs start at RESERVED_PIDS + 1. - * This avoids collisions with the root inode which is 1 - * for pseudo filesystems. - */ - ret = path_from_stashed(&pid->stashed, pid->ino, pidfs_mnt, - get_pid(pid), &path); + ret = path_from_stashed(&pid->stashed, pidfs_mnt, get_pid(pid), &path); if (ret < 0) return ERR_PTR(ret); @@ -261,30 +281,3 @@ void __init pidfs_init(void) if (IS_ERR(pidfs_mnt)) panic("Failed to mount pidfs pseudo filesystem"); } - -bool is_pidfs_sb(const struct super_block *sb) -{ - return sb == pidfs_mnt->mnt_sb; -} - -#else /* !CONFIG_FS_PID */ - -struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags) -{ - struct file *pidfd_file; - - pidfd_file = anon_inode_getfile("[pidfd]", &pidfs_file_operations, pid, - flags | O_RDWR); - if (IS_ERR(pidfd_file)) - return pidfd_file; - - get_pid(pid); - return pidfd_file; -} - -void __init pidfs_init(void) { } -bool is_pidfs_sb(const struct super_block *sb) -{ - return false; -} -#endif diff --git a/include/linux/pid.h b/include/linux/pid.h index c79a0efd0258..a3aad9b4074c 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -45,6 +45,8 @@ * find_pid_ns() using the int nr and struct pid_namespace *ns. */ +#define RESERVED_PIDS 300 + struct upid { int nr; struct pid_namespace *ns; @@ -55,10 +57,8 @@ struct pid refcount_t count; unsigned int level; spinlock_t lock; -#ifdef CONFIG_FS_PID struct dentry *stashed; - unsigned long ino; -#endif + u64 ino; /* lists of tasks that use this pid */ struct hlist_head tasks[PIDTYPE_MAX]; struct hlist_head inodes; diff --git a/include/linux/pidfs.h b/include/linux/pidfs.h index 40dd325a32a6..75bdf9807802 100644 --- a/include/linux/pidfs.h +++ b/include/linux/pidfs.h @@ -4,6 +4,5 @@ struct file *pidfs_alloc_file(struct pid *pid, unsigned int flags); void __init pidfs_init(void); -bool is_pidfs_sb(const struct super_block *sb); #endif /* _LINUX_PID_FS_H */ diff --git a/kernel/pid.c b/kernel/pid.c index 99a0c5eb24b8..da76ed1873f7 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -62,17 +62,13 @@ struct pid init_struct_pid = { int pid_max = PID_MAX_DEFAULT; -#define RESERVED_PIDS 300 - int pid_max_min = RESERVED_PIDS + 1; int pid_max_max = PID_MAX_LIMIT; -#ifdef CONFIG_FS_PID /* * Pseudo filesystems start inode numbering after one. We use Reserved * PIDs as a natural offset. */ static u64 pidfs_ino = RESERVED_PIDS; -#endif /* * PID-map pages start out as NULL, they get allocated upon @@ -280,10 +276,8 @@ struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid, spin_lock_irq(&pidmap_lock); if (!(ns->pid_allocated & PIDNS_ADDING)) goto out_unlock; -#ifdef CONFIG_FS_PID pid->stashed = NULL; pid->ino = ++pidfs_ino; -#endif for ( ; upid >= pid->numbers; --upid) { /* Make the PID visible to find_pid_ns. */ idr_replace(&upid->ns->idr, pid, upid->nr); |