We do not currently handle the holding of any file locks. If a process being checkpointed is holding one, error out of the checkpoint process.
Signed-off-by: Dave Hansen <[email protected]> --- checkpoint/files.c | 12 ++++++++++++ fs/locks.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/fs.h | 6 ++++++ 3 files changed, 53 insertions(+), 0 deletions(-) diff --git a/checkpoint/files.c b/checkpoint/files.c index b622588..46a103d 100644 --- a/checkpoint/files.c +++ b/checkpoint/files.c @@ -272,6 +272,18 @@ 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) { diff --git a/fs/locks.c b/fs/locks.c index a8794f2..721481a 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -1994,6 +1994,41 @@ void locks_remove_posix(struct file *filp, fl_owner_t owner) EXPORT_SYMBOL(locks_remove_posix); +int find_locks_with_owner(struct file *filp, fl_owner_t owner) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + struct file_lock **inode_fl; + int ret = -EEXIST; + + lock_kernel(); + for_each_lock(inode, inode_fl) { + struct file_lock *fl = *inode_fl; + /* + * We could use posix_same_owner() along with a 'fake' + * file_lock. But, the fake file will never have the + * same fl_lmops as the fl that we are looking for and + * posix_same_owner() would just fall back to this + * check anyway. + */ + if (IS_POSIX(fl)) { + if (fl->fl_owner == owner) { + ret = 0; + break; + } + } else if (IS_FLOCK(fl) || IS_LEASE(fl)) { + if (fl->fl_file == filp) { + ret = 0; + break; + } + } else { + WARN(1, "unknown file lock type, fl_flags: %x", + fl->fl_flags); + } + } + unlock_kernel(); + return ret; +} + /* * This function is called on the last close of an open file. */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 5ae34fc..089549b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1122,6 +1122,7 @@ extern void locks_remove_posix(struct file *, fl_owner_t); extern void locks_remove_flock(struct file *); extern void locks_release_private(struct file_lock *); extern void posix_test_lock(struct file *, struct file_lock *); +extern int find_locks_with_owner(struct file *filp, fl_owner_t owner); extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *); extern int posix_lock_file_wait(struct file *, struct file_lock *); extern int posix_unblock_lock(struct file *, struct file_lock *); @@ -1190,6 +1191,11 @@ static inline void locks_remove_posix(struct file *filp, fl_owner_t owner) return; } +static inline int find_locks_with_owner(struct file *filp, fl_owner_t owner) +{ + return -ENOENT; +} + static inline void locks_remove_flock(struct file *filp) { return; -- 1.6.6.rc3 _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
