diff options
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 91 |
1 files changed, 23 insertions, 68 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 0a42e0e9602..134d494158d 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -27,6 +27,7 @@ #include <linux/ramfs.h> #include <linux/log2.h> #include <linux/idr.h> +#include <linux/fs_struct.h> #include <asm/uaccess.h> #include <asm/unistd.h> #include "pnode.h" @@ -694,12 +695,16 @@ static inline void mangle(struct seq_file *m, const char *s) */ int generic_show_options(struct seq_file *m, struct vfsmount *mnt) { - const char *options = mnt->mnt_sb->s_options; + const char *options; + + rcu_read_lock(); + options = rcu_dereference(mnt->mnt_sb->s_options); if (options != NULL && options[0]) { seq_putc(m, ','); mangle(m, options); } + rcu_read_unlock(); return 0; } @@ -720,11 +725,22 @@ EXPORT_SYMBOL(generic_show_options); */ void save_mount_options(struct super_block *sb, char *options) { - kfree(sb->s_options); - sb->s_options = kstrdup(options, GFP_KERNEL); + BUG_ON(sb->s_options); + rcu_assign_pointer(sb->s_options, kstrdup(options, GFP_KERNEL)); } EXPORT_SYMBOL(save_mount_options); +void replace_mount_options(struct super_block *sb, char *options) +{ + char *old = sb->s_options; + rcu_assign_pointer(sb->s_options, options); + if (old) { + synchronize_rcu(); + kfree(old); + } +} +EXPORT_SYMBOL(replace_mount_options); + #ifdef CONFIG_PROC_FS /* iterator */ static void *m_start(struct seq_file *m, loff_t *pos) @@ -1072,9 +1088,7 @@ static int do_umount(struct vfsmount *mnt, int flags) */ if (flags & MNT_FORCE && sb->s_op->umount_begin) { - lock_kernel(); sb->s_op->umount_begin(sb); - unlock_kernel(); } /* @@ -1376,7 +1390,7 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt, if (parent_path) { detach_mnt(source_mnt, parent_path); attach_mnt(source_mnt, path); - touch_mnt_namespace(current->nsproxy->mnt_ns); + touch_mnt_namespace(parent_path->mnt->mnt_ns); } else { mnt_set_mountpoint(dest_mnt, dest_dentry, source_mnt); commit_tree(source_mnt); @@ -1919,8 +1933,9 @@ long do_mount(char *dev_name, char *dir_name, char *type_page, if (data_page) ((char *)data_page)[PAGE_SIZE - 1] = 0; - /* Default to relatime */ - mnt_flags |= MNT_RELATIME; + /* Default to relatime unless overriden */ + if (!(flags & MS_NOATIME)) + mnt_flags |= MNT_RELATIME; /* Separate the per-mountpoint flags */ if (flags & MS_NOSUID) @@ -2093,66 +2108,6 @@ out1: } /* - * Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values. - * It can block. Requires the big lock held. - */ -void set_fs_root(struct fs_struct *fs, struct path *path) -{ - struct path old_root; - - write_lock(&fs->lock); - old_root = fs->root; - fs->root = *path; - path_get(path); - write_unlock(&fs->lock); - if (old_root.dentry) - path_put(&old_root); -} - -/* - * Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values. - * It can block. Requires the big lock held. - */ -void set_fs_pwd(struct fs_struct *fs, struct path *path) -{ - struct path old_pwd; - - write_lock(&fs->lock); - old_pwd = fs->pwd; - fs->pwd = *path; - path_get(path); - write_unlock(&fs->lock); - - if (old_pwd.dentry) - path_put(&old_pwd); -} - -static void chroot_fs_refs(struct path *old_root, struct path *new_root) -{ - struct task_struct *g, *p; - struct fs_struct *fs; - - read_lock(&tasklist_lock); - do_each_thread(g, p) { - task_lock(p); - fs = p->fs; - if (fs) { - atomic_inc(&fs->count); - task_unlock(p); - if (fs->root.dentry == old_root->dentry - && fs->root.mnt == old_root->mnt) - set_fs_root(fs, new_root); - if (fs->pwd.dentry == old_root->dentry - && fs->pwd.mnt == old_root->mnt) - set_fs_pwd(fs, new_root); - put_fs_struct(fs); - } else - task_unlock(p); - } while_each_thread(g, p); - read_unlock(&tasklist_lock); -} - -/* * pivot_root Semantics: * Moves the root file system of the current process to the directory put_old, * makes new_root as the new root file system of the current process, and sets |