>From 46f8a088d15eda817f537cbb17574253a3af4e8c Mon Sep 17 00:00:00 2001 From: Sukadev Bhattiprolu <[email protected]> Date: Thu, 29 Apr 2010 23:43:46 -0700 Subject: [RFC][cr][PATCH 2/6] Checkpoint file-locks
While checkpointing each file-descriptor, find all the locks on the file and save information about the lock in the checkpoint-image. A follow-on patch will use this informaiton to restore the file-locks. Signed-off-by: Sukadev Bhattiprolu <[email protected]> --- fs/checkpoint.c | 98 ++++++++++++++++++++++++++++++++++----- include/linux/checkpoint_hdr.h | 10 ++++ 2 files changed, 95 insertions(+), 13 deletions(-) diff --git a/fs/checkpoint.c b/fs/checkpoint.c index e036a7a..180302e 100644 --- a/fs/checkpoint.c +++ b/fs/checkpoint.c @@ -26,6 +26,7 @@ #include <linux/checkpoint.h> #include <linux/eventpoll.h> #include <linux/eventfd.h> +#include <linux/smp_lock.h> #include <net/sock.h> /************************************************************************** @@ -249,8 +250,86 @@ static int checkpoint_file(struct ckpt_ctx *ctx, void *ptr) return ret; } +static int checkpoint_one_file_lock(struct ckpt_ctx *ctx, struct file *file, + int fd, struct file_lock *lock) +{ + int rc; + struct ckpt_hdr_file_lock *h; + + h = ckpt_hdr_get_type(ctx, sizeof(*h), CKPT_HDR_FILE_LOCK); + if (!h) + return -ENOMEM; + + h->fl_start = lock->fl_start; + h->fl_end = lock->fl_end; + h->fl_type = lock->fl_type; + h->fl_flags = lock->fl_flags; + + rc = ckpt_write_obj(ctx, &h->h); + + ckpt_hdr_put(ctx, h); + + ckpt_debug("Lock [%lld, %lld, %d, 0x%x] fd %d, rc %d\n", lock->fl_start, + lock->fl_end, lock->fl_type, lock->fl_flags, fd, rc); + + return rc; +} + +int +checkpoint_file_locks(struct ckpt_ctx *ctx, struct files_struct *files, + struct file *file, int fd) +{ + int rc; + struct inode *inode; + struct file_lock **lockpp; + struct file_lock *lockp; + struct file_lock last_lock; + + lock_kernel(); + inode = file->f_path.dentry->d_inode; + for_each_lock(inode, lockpp) { + lockp = *lockpp; + ckpt_debug("Found lock [%lld, %lld, %d, 0x%x]\n", + lockp->fl_start, lockp->fl_end, + lockp->fl_type, lockp->fl_flags); + + if (lockp->fl_owner != files) + continue; + + if (IS_POSIX(lockp)) { + rc = checkpoint_one_file_lock(ctx, file, fd, lockp); + if (rc < 0) { + ckpt_err(ctx, rc, "%(T)fd %d, checkpoint " + "lock failed\n", fd); + goto out; + } + } else { + rc = -EBADF; + ckpt_err(ctx, rc, "%(T)fd %d has unsupported file " + "lock type, flags 0x%x\n", fd, + lockp->fl_flags); + goto out; + } + } + + /* + * Checkpoint a dummy file-lock to mark the end of file-locks + * for this fd. + */ + memset(&last_lock, 0, sizeof(struct file_lock)); + last_lock.fl_start = -1; + last_lock.fl_flags = FL_POSIX; + rc = checkpoint_one_file_lock(ctx, file, fd, &last_lock); + if (rc < 0) + ckpt_err(ctx, rc, "%(T)fd %d, checkpoint last-lock failed\n", + fd); +out: + unlock_kernel(); + return rc; +} + /** - * ckpt_write_file_desc - dump the state of a given file descriptor + * checkpoint_file_desc - dump the state of a given file descriptor * @ctx: checkpoint context * @files: files_struct pointer * @fd: file descriptor @@ -282,18 +361,6 @@ static int checkpoint_file_desc(struct ckpt_ctx *ctx, } rcu_read_unlock(); - ret = find_locks_with_owner(file, files); - /* - * find_locks_with_owner() returns an error when there - * are no locks found, so we *want* it to return an error - * code. Its success means we have to fail the checkpoint. - */ - if (!ret) { - ret = -EBADF; - ckpt_err(ctx, ret, "%(T)fd %d has file lock or lease\n", fd); - goto out; - } - /* sanity check (although this shouldn't happen) */ ret = -EBADF; if (!file) { @@ -328,6 +395,11 @@ static int checkpoint_file_desc(struct ckpt_ctx *ctx, h->fd_close_on_exec = coe; ret = ckpt_write_obj(ctx, &h->h); + if (ret < 0) + goto out; + + ret = checkpoint_file_locks(ctx, files, file, fd); + out: ckpt_hdr_put(ctx, h); if (file) diff --git a/include/linux/checkpoint_hdr.h b/include/linux/checkpoint_hdr.h index 790214f..d2a0fcd 100644 --- a/include/linux/checkpoint_hdr.h +++ b/include/linux/checkpoint_hdr.h @@ -144,6 +144,8 @@ enum { #define CKPT_HDR_TTY_LDISC CKPT_HDR_TTY_LDISC CKPT_HDR_EPOLL_ITEMS, /* must be after file-table */ #define CKPT_HDR_EPOLL_ITEMS CKPT_HDR_EPOLL_ITEMS + CKPT_HDR_FILE_LOCK, +#define CKPT_HDR_FILE_LOCK CKPT_HDR_FILE_LOCK CKPT_HDR_MM = 401, #define CKPT_HDR_MM CKPT_HDR_MM @@ -576,6 +578,14 @@ struct ckpt_hdr_file_generic { struct ckpt_hdr_file common; } __attribute__((aligned(8))); +struct ckpt_hdr_file_lock { + struct ckpt_hdr h; + loff_t fl_start; + loff_t fl_end; + __u8 fl_type; + __u8 fl_flags; +}; + struct ckpt_hdr_file_pipe { struct ckpt_hdr_file common; __s32 pipe_objref; -- 1.6.0.4 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
