Dump umask, root, pwd. root, pwd are dumped as names returned by d_path.
FIXME, FIXME, FIXME: think through what to do with overmount and vfsmount themselves!!! FIXME: restore root, pwd, tsk->fs itself Signed-off-by: Alexey Dobriyan <[email protected]> --- include/linux/cr.h | 12 +++ kernel/cr/Makefile | 1 kernel/cr/cpt-sys.c | 6 + kernel/cr/cr-fs.c | 194 ++++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/cr/cr-task.c | 2 kernel/cr/cr.h | 4 + 6 files changed, 219 insertions(+) --- a/include/linux/cr.h +++ b/include/linux/cr.h @@ -41,6 +41,7 @@ struct cr_object_header { #define CR_OBJ_PID 10 #define CR_OBJ_FILES_STRUCT 11 #define CR_OBJ_FD 12 +#define CR_OBJ_FS_STRUCT 13 __u32 cr_type; /* object type */ __u32 cr_len; /* object length in bytes including header */ } __packed; @@ -61,6 +62,7 @@ struct cr_image_task_struct { cr_pos_t cr_pos_real_parent; cr_pos_t cr_pos_mm; cr_pos_t cr_pos_pids[3]; + cr_pos_t cr_pos_fs; cr_pos_t cr_pos_files; cr_pos_t cr_pos_nsproxy; @@ -231,6 +233,16 @@ struct cr_image_vma_content { /* __u8 cr_data[cr_nr_pages * cr_page_size]; */ } __packed; +struct cr_image_fs_struct { + struct cr_object_header cr_hdr; + + __u32 cr_umask; + __u32 cr_root_len; + __u32 cr_pwd_len; + /* __u8 cr_root[cr_root_len] */ + /* __u8 cr_pwd[cr_pwd_len] */ +} __packed; + struct cr_image_files_struct { struct cr_object_header cr_hdr; } __packed; --- a/kernel/cr/Makefile +++ b/kernel/cr/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_CR) += cr.o cr-y := cpt-sys.o rst-sys.o cr-y += cr-context.o cr-y += cr-file.o +cr-y += cr-fs.o cr-y += cr-mm.o cr-y += cr-nsproxy.o cr-y += cr-pid.o --- a/kernel/cr/cpt-sys.c +++ b/kernel/cr/cpt-sys.c @@ -83,6 +83,9 @@ static int cr_collect(struct cr_context *ctx) rv = cr_collect_all_file(ctx); if (rv < 0) return rv; + rv = cr_collect_all_fs_struct(ctx); + if (rv < 0) + return rv; rv = cr_collect_all_pid(ctx); if (rv < 0) return rv; @@ -131,6 +134,9 @@ static int cr_dump(struct cr_context *ctx) rv = cr_dump_all_files_struct(ctx); if (rv < 0) return rv; + rv = cr_dump_all_fs_struct(ctx); + if (rv < 0) + return rv; rv = cr_dump_all_uts_ns(ctx); if (rv < 0) return rv; new file mode 100644 --- /dev/null +++ b/kernel/cr/cr-fs.c @@ -0,0 +1,194 @@ +/* Copyright (C) 2000-2009 Parallels Holdings, Ltd. */ +#include <linux/dcache.h> +#include <linux/fs.h> +#include <linux/fs_struct.h> +#include <linux/sched.h> + +#include <linux/cr.h> +#include "cr.h" + +static int cr_collect_fs_struct(struct cr_context *ctx, struct fs_struct *fs) +{ + int rv; + + rv = cr_collect_object(ctx, fs, CR_CTX_FS_STRUCT); + printk("collect fs_struct %p: rv %d\n", fs, rv); + return rv; +} + +int cr_collect_all_fs_struct(struct cr_context *ctx) +{ + struct cr_object *obj; + int rv; + + for_each_cr_object(ctx, obj, CR_CTX_TASK_STRUCT) { + struct task_struct *tsk = obj->o_obj; + + rv = cr_collect_fs_struct(ctx, tsk->fs); + if (rv < 0) + return rv; + } + for_each_cr_object(ctx, obj, CR_CTX_FS_STRUCT) { + struct fs_struct *fs = obj->o_obj; + unsigned int cnt = fs->users; + + if (obj->o_count != cnt) { + printk("%s: fs_struct %p has external references %lu:%u\n", __func__, fs, obj->o_count, cnt); + return -EINVAL; + } + } + return 0; +} + +static int cr_dump_fs_struct(struct cr_context *ctx, struct cr_object *obj) +{ + struct fs_struct *fs = obj->o_obj; + struct cr_image_fs_struct *i; + char *buf_root, *name_root, *buf_pwd, *name_pwd; + int rv; + + i = cr_prepare_image(CR_OBJ_FS_STRUCT, sizeof(*i)); + if (!i) + return -ENOMEM; + + i->cr_umask = fs->umask; + + buf_root = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf_root) { + kfree(i); + return -ENOMEM; + } + name_root = d_path(&fs->root, buf_root, PAGE_SIZE); + if (IS_ERR(name_root)) { + kfree(buf_root); + kfree(i); + return PTR_ERR(name_root); + } + i->cr_root_len = buf_root + PAGE_SIZE - 1 - name_root; + i->cr_hdr.cr_len += i->cr_root_len; + + buf_pwd = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!buf_pwd) { + kfree(buf_root); + kfree(i); + return -ENOMEM; + } + name_pwd = d_path(&fs->pwd, buf_pwd, PAGE_SIZE); + if (IS_ERR(name_pwd)) { + kfree(buf_pwd); + kfree(buf_root); + kfree(i); + return PTR_ERR(name_pwd); + } + i->cr_pwd_len = buf_pwd + PAGE_SIZE - 1 - name_pwd; + i->cr_hdr.cr_len += i->cr_pwd_len; + + obj->o_pos = ctx->cr_dump_file->f_pos; + rv = cr_write(ctx, i, sizeof(*i)); + if (rv < 0) { + kfree(buf_pwd); + kfree(buf_root); + kfree(i); + return rv; + } + rv = cr_write(ctx, name_root, i->cr_root_len); + if (rv < 0) { + kfree(buf_pwd); + kfree(buf_root); + kfree(i); + return rv; + } + rv = cr_write(ctx, name_pwd, i->cr_pwd_len); + if (rv < 0) { + kfree(buf_pwd); + kfree(buf_root); + kfree(i); + return rv; + } + printk("dump fs_struct %p: umask %03o, root '%.*s', pwd '%.*s'\n", fs, fs->umask, i->cr_root_len, name_root, i->cr_pwd_len, name_pwd); + + kfree(buf_pwd); + kfree(buf_root); + kfree(i); + return 0; +} + +int cr_dump_all_fs_struct(struct cr_context *ctx) +{ + struct cr_object *obj; + int rv; + + for_each_cr_object(ctx, obj, CR_CTX_FS_STRUCT) { + rv = cr_dump_fs_struct(ctx, obj); + if (rv < 0) + return rv; + } + return 0; +} + +int cr_restore_fs_struct(struct cr_context *ctx, loff_t pos) +{ + struct cr_image_fs_struct *i, *tmp; + struct fs_struct *fs; + struct cr_object *obj; + char *cr_root, *cr_pwd; + int rv; + + i = kzalloc(sizeof(*i), GFP_KERNEL); + if (!i) + return -ENOMEM; + rv = cr_pread(ctx, i, sizeof(*i), pos); + if (rv < 0) { + kfree(i); + return rv; + } + if (i->cr_hdr.cr_type != CR_OBJ_FS_STRUCT) { + kfree(i); + return -EINVAL; + } + tmp = i; + i = krealloc(i, sizeof(*i) + i->cr_root_len + i->cr_pwd_len + 2, GFP_KERNEL); + if (!i) { + kfree(tmp); + return -ENOMEM; + } + + cr_root = (char *)(i + 1); + rv = cr_pread(ctx, cr_root, i->cr_root_len, pos + sizeof(*i)); + if (rv < 0) { + kfree(i); + return rv; + } + cr_root[i->cr_root_len] = '\0'; + + cr_pwd = cr_root + i->cr_root_len + 1; + rv = cr_pread(ctx, cr_pwd, i->cr_pwd_len, pos + sizeof(*i) + i->cr_root_len); + if (rv < 0) { + kfree(i); + return rv; + } + cr_pwd[i->cr_pwd_len] = '\0'; + + fs = kmem_cache_zalloc(fs_cachep, GFP_KERNEL); + if (!fs) { + kfree(i); + return -ENOMEM; + } + fs->users = 1; + fs->in_exec = 0; + rwlock_init(&fs->lock); + + fs->umask = i->cr_umask; + + obj = cr_object_create(fs); + if (!obj) { + kmem_cache_free(fs_cachep, fs); + kfree(i); + return -ENOMEM; + } + obj->o_pos = pos; + list_add(&obj->o_list, &ctx->cr_obj[CR_CTX_FS_STRUCT]); + printk("restore fs_struct %p, pos = %lld: umask %03o, root '%s', pwd '%s'\n", fs, (long long)pos, fs->umask, cr_root, cr_pwd); + kfree(i); + return 0; +} --- a/kernel/cr/cr-task.c +++ b/kernel/cr/cr-task.c @@ -127,6 +127,8 @@ static int cr_dump_task_struct(struct cr_context *ctx, struct cr_object *obj) i->cr_pos_pids[2] = tmp->o_pos; else i->cr_pos_pids[2] = CR_POS_UNDEF; + tmp = cr_find_obj_by_ptr(ctx, tsk->fs, CR_CTX_FS_STRUCT); + i->cr_pos_fs = tmp->o_pos; tmp = cr_find_obj_by_ptr(ctx, tsk->files, CR_CTX_FILES_STRUCT); i->cr_pos_files = tmp->o_pos; --- a/kernel/cr/cr.h +++ b/kernel/cr/cr.h @@ -24,6 +24,7 @@ struct cr_object { enum cr_context_obj_type { CR_CTX_FILE, CR_CTX_FILES_STRUCT, + CR_CTX_FS_STRUCT, CR_CTX_MM_STRUCT, CR_CTX_NSPROXY, CR_CTX_PID, @@ -73,6 +74,7 @@ static inline void __user *cr_restore_ptr(__u64 ptr) int cr_collect_all_files_struct(struct cr_context *ctx); int cr_collect_all_file(struct cr_context *ctx); +int cr_collect_all_fs_struct(struct cr_context *ctx); int cr_collect_all_mm_struct(struct cr_context *ctx); int cr_collect_all_nsproxy(struct cr_context *ctx); int cr_collect_all_pid_ns(struct cr_context *ctx); @@ -82,6 +84,7 @@ int cr_collect_all_uts_ns(struct cr_context *ctx); int cr_dump_all_files_struct(struct cr_context *ctx); int cr_dump_all_file(struct cr_context *ctx); +int cr_dump_all_fs_struct(struct cr_context *ctx); int cr_dump_all_mm_struct(struct cr_context *ctx); int cr_dump_all_nsproxy(struct cr_context *ctx); int cr_dump_all_pid_ns(struct cr_context *ctx); @@ -91,6 +94,7 @@ int cr_dump_all_uts_ns(struct cr_context *ctx); int cr_restore_files_struct(struct cr_context *ctx, loff_t pos); int cr_restore_file(struct cr_context *ctx, loff_t pos); +int cr_restore_fs_struct(struct cr_context *ctx, loff_t pos); int cr_restore_mm_struct(struct cr_context *ctx, loff_t pos); int cr_restore_nsproxy(struct cr_context *ctx, loff_t pos); int cr_restore_pid_ns(struct cr_context *ctx, loff_t pos); _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
