Merge tag 'filelock-v5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux
Pull file locking updates from Jeff Layton:
"Just a couple of minor bugfixes, a revision to a tracepoint to account
for some earlier changes to the internals, and a patch to add a
pr_warn message when someone tries to mount a filesystem with '-o
mand' on a kernel that has that support disabled"
* tag 'filelock-v5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
locks: fix a memory leak bug in __break_lease()
locks: print a warning when mount fails due to lack of "mand" support
locks: Fix procfs output for file leases
locks: revise generic_add_lease tracepoint
diff --git a/Documentation/filesystems/mandatory-locking.txt b/Documentation/filesystems/mandatory-locking.txt
index 0979d1d..a251ca3 100644
--- a/Documentation/filesystems/mandatory-locking.txt
+++ b/Documentation/filesystems/mandatory-locking.txt
@@ -169,3 +169,13 @@
permissions (remove the setgid bit) before trying to read or write to it.
Of course, that might be a bit tricky if the system is hung :-(
+7. The "mand" mount option
+--------------------------
+Mandatory locking is disabled on all filesystems by default, and must be
+administratively enabled by mounting with "-o mand". That mount option
+is only allowed if the mounting task has the CAP_SYS_ADMIN capability.
+
+Since kernel v4.5, it is possible to disable mandatory locking
+altogether by setting CONFIG_MANDATORY_FILE_LOCKING to "n". A kernel
+with this disabled will reject attempts to mount filesystems with the
+"mand" mount option with the error status EPERM.
diff --git a/fs/locks.c b/fs/locks.c
index 686eae2..a364ebc 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1592,7 +1592,7 @@
ctx = smp_load_acquire(&inode->i_flctx);
if (!ctx) {
WARN_ON_ONCE(1);
- return error;
+ goto free_lock;
}
percpu_down_read(&file_rwsem);
@@ -1672,6 +1672,7 @@
spin_unlock(&ctx->flc_lock);
percpu_up_read(&file_rwsem);
locks_dispose_list(&dispose);
+free_lock:
locks_free_lock(new_fl);
return error;
}
@@ -2784,10 +2785,10 @@
? (fl->fl_type & LOCK_WRITE) ? "RW " : "READ "
: (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE ");
} else {
- seq_printf(f, "%s ",
- (lease_breaking(fl))
- ? (fl->fl_type == F_UNLCK) ? "UNLCK" : "READ "
- : (fl->fl_type == F_WRLCK) ? "WRITE" : "READ ");
+ int type = IS_LEASE(fl) ? target_leasetype(fl) : fl->fl_type;
+
+ seq_printf(f, "%s ", (type == F_WRLCK) ? "WRITE" :
+ (type == F_RDLCK) ? "READ" : "UNLCK");
}
if (inode) {
/* userspace relies on this representation of dev_t */
diff --git a/fs/namespace.c b/fs/namespace.c
index 81edb7e..227f7b3 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1643,13 +1643,18 @@
return ns_capable(current->nsproxy->mnt_ns->user_ns, CAP_SYS_ADMIN);
}
+#ifdef CONFIG_MANDATORY_FILE_LOCKING
static inline bool may_mandlock(void)
{
-#ifndef CONFIG_MANDATORY_FILE_LOCKING
- return false;
-#endif
return capable(CAP_SYS_ADMIN);
}
+#else
+static inline bool may_mandlock(void)
+{
+ pr_warn("VFS: \"mand\" mount option not supported");
+ return false;
+}
+#endif
/*
* Now umount can handle mount points as well as block devices.
diff --git a/include/trace/events/filelock.h b/include/trace/events/filelock.h
index 4b73592..c705e49 100644
--- a/include/trace/events/filelock.h
+++ b/include/trace/events/filelock.h
@@ -176,7 +176,7 @@
TP_STRUCT__entry(
__field(unsigned long, i_ino)
__field(int, wcount)
- __field(int, dcount)
+ __field(int, rcount)
__field(int, icount)
__field(dev_t, s_dev)
__field(fl_owner_t, fl_owner)
@@ -188,16 +188,16 @@
__entry->s_dev = inode->i_sb->s_dev;
__entry->i_ino = inode->i_ino;
__entry->wcount = atomic_read(&inode->i_writecount);
- __entry->dcount = d_count(fl->fl_file->f_path.dentry);
+ __entry->rcount = atomic_read(&inode->i_readcount);
__entry->icount = atomic_read(&inode->i_count);
- __entry->fl_owner = fl ? fl->fl_owner : NULL;
- __entry->fl_flags = fl ? fl->fl_flags : 0;
- __entry->fl_type = fl ? fl->fl_type : 0;
+ __entry->fl_owner = fl->fl_owner;
+ __entry->fl_flags = fl->fl_flags;
+ __entry->fl_type = fl->fl_type;
),
- TP_printk("dev=0x%x:0x%x ino=0x%lx wcount=%d dcount=%d icount=%d fl_owner=0x%p fl_flags=%s fl_type=%s",
+ TP_printk("dev=0x%x:0x%x ino=0x%lx wcount=%d rcount=%d icount=%d fl_owner=0x%p fl_flags=%s fl_type=%s",
MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
- __entry->i_ino, __entry->wcount, __entry->dcount,
+ __entry->i_ino, __entry->wcount, __entry->rcount,
__entry->icount, __entry->fl_owner,
show_fl_flags(__entry->fl_flags),
show_fl_type(__entry->fl_type))
