[CRIU] [PATCH 35/39] mount: use per-namespace mntinfo_tree (v2)
Andrey Vagin
avagin at openvz.org
Mon Apr 21 07:23:45 PDT 2014
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 at openvz.org>
---
cr-check.c | 5 ----
cr-dump.c | 12 --------
cr-restore.c | 3 --
files-reg.c | 70 +++++++++++++++++++++++++++++++++------------
include/mount.h | 7 +++--
mount.c | 88 +++++++++++++++++++++++++--------------------------------
sk-unix.c | 13 ++++++++-
7 files changed, 106 insertions(+), 92 deletions(-)
diff --git a/cr-check.c b/cr-check.c
index 14f1e4d..f7ca39c 100644
--- a/cr-check.c
+++ b/cr-check.c
@@ -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();
diff --git a/cr-dump.c b/cr-dump.c
index 64b4310..86351e5 100644
--- a/cr-dump.c
+++ b/cr-dump.c
@@ -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;
diff --git a/cr-restore.c b/cr-restore.c
index 521a388..1ff0ffa 100644
--- a/cr-restore.c
+++ b/cr-restore.c
@@ -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);
diff --git a/files-reg.c b/files-reg.c
index a425ce3..0e090a2 100644
--- a/files-reg.c
+++ b/files-reg.c
@@ -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;
+
+ nsid = lookup_nsid_by_mnt_id(rfi->rfe->mnt_id);
+ if (nsid == NULL)
+ return -1;
+
+ mntns_root = mntns_collect_root(nsid->pid);
- fd = open(rfi->path, flags);
+ fd = openat(mntns_root, rfi->path, flags);
if (fd < 0) {
pr_perror("Can't open file %s on restore", rfi->path);
return fd;
diff --git a/include/mount.h b/include/mount.h
index 729a638..b66aae6 100644
--- a/include/mount.h
+++ b/include/mount.h
@@ -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);
diff --git a/mount.c b/mount.c
index 272718f..559bc4c 100644
--- a/mount.c
+++ b/mount.c
@@ -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_temporary_roots())
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;
}
diff --git a/sk-unix.c b/sk-unix.c
index a36a1a1..b2ca643 100644
--- a/sk-unix.c
+++ b/sk-unix.c
@@ -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",
--
1.8.5.3
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