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mount: use per-namespace mntinfo_tree (v2)

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This patch removes the global mntinfo_tree and collect_mount_info where
it was constructed. The mntinfo list is filled from dump_mnt_ns,
rst_collect_local_mntns, collect_mnt_namespaces and read_mnt_ns_img.

A mountinfo entry contains a reference on a proper ns_id entry, so
we cau use mnt_id to look up a proper mount namespace.

v2: remove trash after rebasing.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This commit is contained in:
Andrey Vagin 2014-04-21 18:23:45 +04:00 committed by Pavel Emelyanov
parent 03c69251ab
commit 2f4be997b6
7 changed files with 106 additions and 92 deletions
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5
cr-check.c
View File

@ -554,11 +554,6 @@ int cr_check(void)
if (mntinfo == NULL)
return -1;
if (collect_mount_info(getpid())) {
pr_err("Can't collect mount infos\n");
return -1;
}
ret |= check_map_files();
ret |= check_sock_diag();
ret |= check_ns_last_pid();

12
cr-dump.c
View File

@ -1656,12 +1656,6 @@ int cr_pre_dump_tasks(pid_t pid)
if (gen_predump_ns_mask())
goto err;
if (collect_mount_info(pid))
goto err;
if (mntns_collect_root(root_item->pid.real) < 0)
goto err;
if (collect_mnt_namespaces() < 0)
goto err;
@ -1769,12 +1763,6 @@ int cr_dump_tasks(pid_t pid)
if (collect_file_locks())
goto err;
if (collect_mount_info(pid))
goto err;
if (mntns_collect_root(root_item->pid.real) < 0)
goto err;
if (dump_mnt_namespaces() < 0)
goto err;

3
cr-restore.c
View File

@ -1237,9 +1237,6 @@ static int restore_task_with_children(void *_arg)
if (restore_finish_stage(CR_STATE_RESTORE_NS) < 0)
exit(1);
if (collect_mount_info(getpid()))
exit(1);
if (prepare_namespace(current, ca->clone_flags))
exit(1);

70
files-reg.c
View File

@ -23,6 +23,7 @@
#include "fs-magic.h"
#include "asm/atomic.h"
#include "namespaces.h"
#include "proc_parse.h"
#include "protobuf.h"
#include "protobuf/regfile.pb-c.h"
@ -56,6 +57,7 @@ static mutex_t *ghost_file_mutex;
*/
struct link_remap_rlb {
struct list_head list;
pid_t pid;
char *path;
};
static LIST_HEAD(link_remaps);
@ -72,6 +74,7 @@ static int open_remap_ghost(struct reg_file_info *rfi,
struct ghost_file *gf;
GhostFileEntry *gfe = NULL;
int gfd, ifd, ghost_flags;
char *root, path[PATH_MAX];
rfe->remap_id &= ~REMAP_GHOST;
list_for_each_entry(gf, &ghost_files, list)
@ -86,6 +89,12 @@ static int open_remap_ghost(struct reg_file_info *rfi,
pr_info("Opening ghost file %#x for %s\n", rfe->remap_id, rfi->path);
root = rst_get_mnt_root(rfi->rfe->mnt_id);
if (root == NULL) {
pr_err("The %d mount is not found\n", rfi->rfe->mnt_id);
return -1;
}
gf = shmalloc(sizeof(*gf));
if (!gf)
return -1;
@ -119,9 +128,10 @@ static int open_remap_ghost(struct reg_file_info *rfi,
} else
ghost_flags = O_WRONLY | O_CREAT | O_EXCL;
gfd = open(gf->remap.path, ghost_flags, gfe->mode);
snprintf(path, sizeof(path), "%s/%s", root, gf->remap.path);
gfd = open(path, ghost_flags, gfe->mode);
if (gfd < 0) {
pr_perror("Can't open ghost file %s", gf->remap.path);
pr_perror("Can't open ghost file %s", path);
goto close_ifd;
}
@ -290,7 +300,8 @@ struct file_remap *lookup_ghost_remap(u32 dev, u32 ino)
return NULL;
}
static int dump_ghost_remap(char *path, const struct stat *st, int lfd, u32 id)
static int dump_ghost_remap(char *path, const struct stat *st,
int lfd, u32 id, struct ns_id *nsid)
{
struct ghost_file *gf;
RemapFilePathEntry rpe = REMAP_FILE_PATH_ENTRY__INIT;
@ -304,7 +315,7 @@ static int dump_ghost_remap(char *path, const struct stat *st, int lfd, u32 id)
return -1;
}
phys_dev = phys_stat_resolve_dev(st->st_dev, path);
phys_dev = phys_stat_resolve_dev(nsid->mnt.mntinfo_tree, st->st_dev, path);
list_for_each_entry(gf, &ghost_files, list)
if ((gf->dev == phys_dev) && (gf->ino == st->st_ino))
goto dump_entry;
@ -339,9 +350,10 @@ static void __rollback_link_remaps(bool do_unlink)
if (!opts.link_remap_ok)
return;
mntns_root = get_service_fd(ROOT_FD_OFF);
list_for_each_entry_safe(rlb, tmp, &link_remaps, list) {
mntns_root = mntns_collect_root(rlb->pid);
if (mntns_root < 0)
return;
list_del(&rlb->list);
if (do_unlink)
unlinkat(mntns_root, rlb->path, 0);
@ -353,7 +365,8 @@ static void __rollback_link_remaps(bool do_unlink)
void delete_link_remaps(void) { __rollback_link_remaps(true); }
void free_link_remaps(void) { __rollback_link_remaps(false); }
static int create_link_remap(char *path, int len, int lfd, u32 *idp)
static int create_link_remap(char *path, int len, int lfd,
u32 *idp, struct ns_id *nsid)
{
char link_name[PATH_MAX], *tmp;
RegFileEntry rfe = REG_FILE_ENTRY__INIT;
@ -394,7 +407,7 @@ static int create_link_remap(char *path, int len, int lfd, u32 *idp)
/* Any 'unique' name works here actually. Remap works by reg-file ids. */
snprintf(tmp + 1, sizeof(link_name) - (size_t)(tmp - link_name - 1), "link_remap.%d", rfe.id);
mntns_root = get_service_fd(ROOT_FD_OFF);
mntns_root = mntns_collect_root(nsid->pid);
if (linkat(lfd, "", mntns_root, link_name, AT_EMPTY_PATH) < 0) {
pr_perror("Can't link remap to %s", path);
@ -411,6 +424,8 @@ static int create_link_remap(char *path, int len, int lfd, u32 *idp)
if (rlb)
rlb->path = strdup(link_name);
rlb->pid = nsid->pid;
if (!rlb || !rlb->path) {
pr_perror("Can't register rollback for %s", path);
xfree(rlb ? rlb->path : NULL);
@ -422,12 +437,13 @@ static int create_link_remap(char *path, int len, int lfd, u32 *idp)
return pb_write_one(fdset_fd(glob_fdset, CR_FD_REG_FILES), &rfe, PB_REG_FILE);
}
static int dump_linked_remap(char *path, int len, const struct stat *ost, int lfd, u32 id)
static int dump_linked_remap(char *path, int len, const struct stat *ost,
int lfd, u32 id, struct ns_id *nsid)
{
u32 lid;
RemapFilePathEntry rpe = REMAP_FILE_PATH_ENTRY__INIT;
if (create_link_remap(path, len, lfd, &lid))
if (create_link_remap(path, len, lfd, &lid, nsid))
return -1;
rpe.orig_id = id;
@ -471,7 +487,8 @@ static inline bool nfs_silly_rename(char *rpath, const struct fd_parms *parms)
return (parms->fs_type == NFS_SUPER_MAGIC) && is_sillyrename_name(rpath);
}
static int check_path_remap(char *rpath, int plen, const struct fd_parms *parms, int lfd, u32 id)
static int check_path_remap(char *rpath, int plen, const struct fd_parms *parms,
int lfd, u32 id, struct ns_id *nsid)
{
int ret, mntns_root;
struct stat pst;
@ -484,7 +501,7 @@ static int check_path_remap(char *rpath, int plen, const struct fd_parms *parms,
* be careful whether anybody still has any of its hardlinks
* also open.
*/
return dump_ghost_remap(rpath + 1, ost, lfd, id);
return dump_ghost_remap(rpath + 1, ost, lfd, id, nsid);
if (nfs_silly_rename(rpath, parms)) {
/*
@ -495,10 +512,12 @@ static int check_path_remap(char *rpath, int plen, const struct fd_parms *parms,
* links on it) to have some persistent name at hands.
*/
pr_debug("Dump silly-rename linked remap for %x\n", id);
return dump_linked_remap(rpath + 1, plen - 1, ost, lfd, id);
return dump_linked_remap(rpath + 1, plen - 1, ost, lfd, id, nsid);
}
mntns_root = get_service_fd(ROOT_FD_OFF);
mntns_root = mntns_collect_root(nsid->pid);
if (mntns_root < 0)
return -1;
ret = fstatat(mntns_root, rpath, &pst, 0);
if (ret < 0) {
@ -510,7 +529,8 @@ static int check_path_remap(char *rpath, int plen, const struct fd_parms *parms,
*/
if (errno == ENOENT)
return dump_linked_remap(rpath + 1, plen - 1, ost, lfd, id);
return dump_linked_remap(rpath + 1, plen - 1,
ost, lfd, id, nsid);
pr_perror("Can't stat path");
return -1;
@ -547,6 +567,7 @@ static int check_path_remap(char *rpath, int plen, const struct fd_parms *parms,
int dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p)
{
struct fd_link _link, *link;
struct ns_id *nsid;
int rfd;
RegFileEntry rfe = REG_FILE_ENTRY__INIT;
@ -568,6 +589,12 @@ int dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p)
rfe.has_mnt_id = true;
}
nsid = lookup_nsid_by_mnt_id(p->mnt_id);
if (nsid == NULL) {
pr_err("Unable to look up the %d mount\n", p->mnt_id);
return -1;
}
pr_info("Dumping path for %d fd via self %d [%s]\n",
p->fd, lfd, &link->name[1]);
@ -579,7 +606,7 @@ int dump_one_reg_file(int lfd, u32 id, const struct fd_parms *p)
return -1;
}
if (check_path_remap(link->name, link->len, p, lfd, id))
if (check_path_remap(link->name, link->len, p, lfd, id, nsid))
return -1;
rfe.id = id;
@ -679,9 +706,16 @@ int open_path(struct file_desc *d,
static int do_open_reg_noseek_flags(struct reg_file_info *rfi, void *arg)
{
u32 flags = *(u32 *)arg;
int fd;
int fd, mntns_root;
struct ns_id *nsid;
fd = open(rfi->path, flags);
nsid = lookup_nsid_by_mnt_id(rfi->rfe->mnt_id);
if (nsid == NULL)
return -1;
mntns_root = mntns_collect_root(nsid->pid);
fd = openat(mntns_root, rfi->path, flags);
if (fd < 0) {
pr_perror("Can't open file %s on restore", rfi->path);
return fd;

7
include/mount.h
View File

@ -9,7 +9,6 @@ extern struct ns_id *lookup_nsid_by_mnt_id(int mnt_id);
struct proc_mountinfo;
extern int open_mount(unsigned int s_dev);
extern int collect_mount_info(pid_t pid);
extern struct fstype *find_fstype_by_name(char *fst);
struct cr_fdset;
@ -26,8 +25,10 @@ extern struct mount_info *lookup_mnt_sdev(unsigned int s_dev);
extern struct ns_desc mnt_ns_desc;
extern dev_t phys_stat_resolve_dev(dev_t st_dev, const char *path);
extern bool phys_stat_dev_match(dev_t st_dev, dev_t phys_dev, const char *path);
extern dev_t phys_stat_resolve_dev(struct mount_info *tree,
dev_t st_dev, const char *path);
extern bool phys_stat_dev_match(struct mount_info *tree, dev_t st_dev,
dev_t phys_dev, const char *path);
extern int restore_task_mnt_ns(struct ns_id *nsid, pid_t pid);
extern int fini_mnt_ns(void);

88
mount.c
View File

@ -33,13 +33,6 @@
* Single linked list of mount points get from proc/images
*/
struct mount_info *mntinfo;
/*
* Tree of mount points. When required is generated from
* the mntinfo list. Tree elements are sorted, so that it
* represents the real FS visibility and is thus suitable
* for umounting or path resolution.
*/
static struct mount_info *mntinfo_tree;
static int open_mountpoint(struct mount_info *pm);
@ -83,31 +76,6 @@ int open_mount(unsigned int s_dev)
return -ENOENT;
}
int collect_mount_info(pid_t pid)
{
pr_info("Collecting mountinfo\n");
mntinfo = parse_mountinfo(pid, NULL);
if (!mntinfo) {
pr_err("Parsing mountinfo %d failed\n", getpid());
return -1;
}
/*
* Build proper tree in any case -- for NEWNS one we'll use
* it for old NS clean, otherwise we'll use the tree for
* path resolution (btrfs stat workaround).
*/
mntinfo_tree = mnt_build_tree(mntinfo);
if (!mntinfo_tree) {
pr_err("Building mount tree %d failed\n", getpid());
return -1;
}
return 0;
}
static struct mount_info *__lookup_mnt_id(struct mount_info *list, int id)
{
struct mount_info *m;
@ -135,7 +103,7 @@ struct mount_info *lookup_mnt_sdev(unsigned int s_dev)
return NULL;
}
static struct mount_info *mount_resolve_path(const char *path)
static struct mount_info *mount_resolve_path(struct mount_info *mntinfo_tree, const char *path)
{
size_t pathlen = strlen(path);
struct mount_info *m = mntinfo_tree, *c;
@ -164,11 +132,12 @@ static struct mount_info *mount_resolve_path(const char *path)
return m;
}
dev_t phys_stat_resolve_dev(dev_t st_dev, const char *path)
dev_t phys_stat_resolve_dev(struct mount_info *tree,
dev_t st_dev, const char *path)
{
struct mount_info *m;
m = mount_resolve_path(path);
m = mount_resolve_path(tree, path);
/*
* BTRFS returns subvolume dev-id instead of
* superblock dev-id, in such case return device
@ -178,12 +147,13 @@ dev_t phys_stat_resolve_dev(dev_t st_dev, const char *path)
MKKDEV(MAJOR(st_dev), MINOR(st_dev)) : m->s_dev;
}
bool phys_stat_dev_match(dev_t st_dev, dev_t phys_dev, const char *path)
bool phys_stat_dev_match(struct mount_info *tree, dev_t st_dev,
dev_t phys_dev, const char *path)
{
if (st_dev == kdev_to_odev(phys_dev))
return true;
return phys_dev == phys_stat_resolve_dev(st_dev, path);
return phys_dev == phys_stat_resolve_dev(tree, st_dev, path);
}
/*
@ -508,7 +478,7 @@ static int __open_mountpoint(struct mount_info *pm, int mnt_fd)
goto err;
}
dev = phys_stat_resolve_dev(st.st_dev, pm->mountpoint + 1);
dev = phys_stat_resolve_dev(pm->nsid->mnt.mntinfo_tree, st.st_dev, pm->mountpoint + 1);
if (dev != pm->s_dev) {
pr_err("The file system %#x (%#x) %s %s is inaccessible\n",
pm->s_dev, (int)dev, pm->fstype->name, pm->mountpoint);
@ -882,6 +852,13 @@ int dump_mnt_ns(struct ns_id *ns)
if (dump_one_mountpoint(pm, img_fd))
goto err;
if (mntinfo == NULL)
mntinfo = pms;
else {
for (pm = mntinfo; pm->next != NULL; pm = pm->next);
pm->next = pms;
}
ret = 0;
err:
close(img_fd);
@ -1445,7 +1422,8 @@ int rst_collect_local_mntns()
nsid->pid = getpid();
futex_set(&nsid->created, 1);
if (collect_mntinfo(nsid) == NULL)
mntinfo = collect_mntinfo(nsid);
if (mntinfo == NULL)
return -1;
nsid->next = ns_ids;
@ -1565,6 +1543,10 @@ static struct mount_info *read_mnt_ns_img()
nsid = nsid->next;
}
/* Here is not matter where the mount list is saved */
mntinfo = pms;
return pms;
err:
return NULL;
@ -1674,13 +1656,10 @@ static int populate_mnt_ns(int ns_pid, struct mount_info *mis)
struct mount_info *pms;
struct ns_id *nsid;
mntinfo_tree = NULL;
mntinfo = mis;
if (prepare_roots_yard())
return -1;
pms = mnt_build_tree(mntinfo);
pms = mnt_build_tree(mis);
if (!pms)
return -1;
@ -1694,7 +1673,6 @@ static int populate_mnt_ns(int ns_pid, struct mount_info *mis)
if (validate_mounts(mis, false))
return -1;
mntinfo_tree = pms;
return mnt_tree_for_each(pms, do_mount_one);
}
@ -1762,7 +1740,7 @@ int prepare_mnt_ns(int ns_pid)
struct mount_info *mi;
/* moving a mount residing under a shared mount is invalid. */
mi = mount_resolve_path(opts.root);
mi = mount_resolve_path(ns.mnt.mntinfo_tree, opts.root);
if (mi == NULL) {
pr_err("Unable to find mount point for %s\n", opts.root);
return -1;
@ -1877,14 +1855,15 @@ struct ns_id *lookup_nsid_by_mnt_id(int mnt_id)
int collect_mnt_namespaces(void)
{
struct mount_info *pm;
struct mount_info *pm, *pms;
struct ns_id *ns;
int ret = -1;
for (ns = ns_ids; ns; ns = ns->next) {
if (ns->pid == getpid()) {
if (!(root_ns_mask & CLONE_NEWNS)) {
if (collect_mntinfo(ns) == NULL)
mntinfo = collect_mntinfo(ns);
if (mntinfo == NULL)
return -1;
}
/* Skip current namespaces, which are in the list too */
@ -1896,9 +1875,17 @@ int collect_mnt_namespaces(void)
pr_info("Dump MNT namespace (mountpoints) %d via %d\n",
ns->id, ns->pid);
pm = collect_mntinfo(ns);
if (pm == NULL)
pms = collect_mntinfo(ns);
if (pms == NULL)
goto err;
if (mntinfo == NULL)
mntinfo = pms;
else {
for (pm = mntinfo; pm->next != NULL; pm = pm->next);
pm->next = pms;
}
}
ret = 0;
err:
@ -1914,7 +1901,8 @@ int dump_mnt_namespaces(void)
/* Skip current namespaces, which are in the list too */
if (ns->pid == getpid()) {
if (!(root_ns_mask & CLONE_NEWNS))
if (collect_mntinfo(ns) == NULL)
mntinfo = collect_mntinfo(ns);
if (mntinfo == NULL)
return -1;
continue;
}

13
sk-unix.c
View File

@ -25,6 +25,8 @@
#include "mount.h"
#include "cr-service.h"
#include "plugin.h"
#include "namespaces.h"
#include "pstree.h"
#include "protobuf.h"
#include "protobuf/sk-unix.pb-c.h"
@ -366,8 +368,16 @@ static int unix_collect_one(const struct unix_diag_msg *m,
{
struct unix_sk_desc *d;
char *name = NULL;
struct ns_id *ns;
int ret = 0;
ns = lookup_ns_by_id(root_item->ids->mnt_ns_id, &mnt_ns_desc);
if (ns == NULL)
return -1;
if (mntns_collect_root(ns->pid) < 0)
return -1;
d = xzalloc(sizeof(*d));
if (!d)
return -1;
@ -432,7 +442,8 @@ static int unix_collect_one(const struct unix_diag_msg *m,
name, m->udiag_ino);
drop_path = true;
} else if ((st.st_ino != uv->udiag_vfs_ino) ||
!phys_stat_dev_match(st.st_dev, uv->udiag_vfs_dev, name)) {
!phys_stat_dev_match(ns->mnt.mntinfo_tree, st.st_dev,
uv->udiag_vfs_dev, name)) {
pr_info("unix: Dropping path %s for "
"unlinked bound "
"sk %#x.%#x real %#x.%#x\n",