The patch titled
r/o bind mounts: elevate writer count for custom 'struct file'
has been added to the -mm tree. Its filename is
ro-bind-mounts-elevate-writer-count-for-custom-struct-file.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: r/o bind mounts: elevate writer count for custom 'struct file'
From: Dave Hansen <haveblue@xxxxxxxxxx>
Some filesystems forego the vfs and may_open() and create their own 'struct
file's. Any of these users which set the write flag on the file will cause an
extra mnt_drop_write() on __fput(), thus dropping the reference count too low.
These users tend to have artifical in-kernel vfsmounts which aren't really
exposed to userspace and can't be remounted, but this patch is included for
completeness and so that the warnings don't trip over these cases.
Signed-off-by: Dave Hansen <haveblue@xxxxxxxxxx>
Cc: Serge Hallyn <serue@xxxxxxxxxx>
Cc: Herbert Poetzl <herbert@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/hugetlbfs/inode.c | 2 ++
mm/shmem.c | 2 ++
mm/tiny-shmem.c | 2 ++
net/socket.c | 3 +++
4 files changed, 9 insertions(+)
diff -puN fs/hugetlbfs/inode.c~ro-bind-mounts-elevate-writer-count-for-custom-struct-file fs/hugetlbfs/inode.c
--- a/fs/hugetlbfs/inode.c~ro-bind-mounts-elevate-writer-count-for-custom-struct-file
+++ a/fs/hugetlbfs/inode.c
@@ -790,6 +790,8 @@ struct file *hugetlb_zero_setup(size_t s
file->f_mapping = inode->i_mapping;
file->f_op = &hugetlbfs_file_operations;
file->f_mode = FMODE_WRITE | FMODE_READ;
+ error = mnt_want_write(hugetlbfs_vfsmount);
+ WARN_ON(error);
return file;
out_inode:
diff -puN mm/shmem.c~ro-bind-mounts-elevate-writer-count-for-custom-struct-file mm/shmem.c
--- a/mm/shmem.c~ro-bind-mounts-elevate-writer-count-for-custom-struct-file
+++ a/mm/shmem.c
@@ -2326,6 +2326,8 @@ struct file *shmem_file_setup(char *name
file->f_mapping = inode->i_mapping;
file->f_op = &shmem_file_operations;
file->f_mode = FMODE_WRITE | FMODE_READ;
+ error = mnt_want_write(shm_mnt);
+ WARN_ON(error);
return file;
close_file:
diff -puN mm/tiny-shmem.c~ro-bind-mounts-elevate-writer-count-for-custom-struct-file mm/tiny-shmem.c
--- a/mm/tiny-shmem.c~ro-bind-mounts-elevate-writer-count-for-custom-struct-file
+++ a/mm/tiny-shmem.c
@@ -88,6 +88,8 @@ struct file *shmem_file_setup(char *name
file->f_mapping = inode->i_mapping;
file->f_op = &ramfs_file_operations;
file->f_mode = FMODE_WRITE | FMODE_READ;
+ error = mnt_want_write(shm_mnt);
+ WARN_ON(error);
/* notify everyone as to the change of file size */
error = do_truncate(dentry, size, 0, file);
diff -puN net/socket.c~ro-bind-mounts-elevate-writer-count-for-custom-struct-file net/socket.c
--- a/net/socket.c~ro-bind-mounts-elevate-writer-count-for-custom-struct-file
+++ a/net/socket.c
@@ -396,6 +396,7 @@ static int sock_attach_fd(struct socket
{
struct qstr this;
char name[32];
+ int error;
this.len = sprintf(name, "[%lu]", SOCK_INODE(sock)->i_ino);
this.name = name;
@@ -416,6 +417,8 @@ static int sock_attach_fd(struct socket
file->f_flags = O_RDWR;
file->f_pos = 0;
file->private_data = sock;
+ error = mnt_want_write(sock_mnt);
+ WARN_ON(error);
return 0;
}
_
Patches currently in -mm which might be from haveblue@xxxxxxxxxx are
origin.patch
catch-notification-of-memory-add-event-of-acpi-via-container-driver-register-start-func-for-memory-device.patch
catch-notification-of-memory-add-event-of-acpi-via-container-driveravoid-redundant-call-add_memory.patch
pgdat-allocation-for-new-node-add-specify-node-id.patch
pgdat-allocation-for-new-node-add-get-node-id-by-acpi.patch
pgdat-allocation-for-new-node-add-generic-alloc-node_data.patch
pgdat-allocation-for-new-node-add-refresh-node_data.patch
pgdat-allocation-for-new-node-add-export-kswapd-start-func.patch
pgdat-allocation-for-new-node-add-call-pgdat-allocation.patch
node-hotplug-register-cpu-remove-node-struct.patch
acpi-dock-driver.patch
ro-bind-mounts-prepare-for-write-access-checks-collapse-if.patch
ro-bind-mounts-r-o-bind-mount-prepwork-move-open_nameis-vfs_create.patch
ro-bind-mounts-add-vfsmount-writer-count.patch
ro-bind-mounts-elevate-mnt-writers-for-callers-of-vfs_mkdir.patch
ro-bind-mounts-elevate-write-count-during-entire-ncp_ioctl.patch
ro-bind-mounts-sys_symlinkat-elevate-write-count-around-vfs_symlink.patch
ro-bind-mounts-elevate-mount-count-for-extended-attributes.patch
ro-bind-mounts-sys_linkat-elevate-write-count-around-vfs_link.patch
ro-bind-mounts-mount_is_safe-add-comment.patch
ro-bind-mounts-unix_find_other-elevate-write-count-for-touch_atime.patch
ro-bind-mounts-elevate-write-count-over-calls-to-vfs_rename.patch
ro-bind-mounts-tricky-elevate-write-count-files-are-opened.patch
ro-bind-mounts-elevate-writer-count-for-do_sys_truncate.patch
ro-bind-mounts-elevate-write-count-for-do_utimes.patch
ro-bind-mounts-elevate-write-count-for-do_sys_utime-and-touch_atime.patch
ro-bind-mounts-sys_mknodat-elevate-write-count-for-vfs_mknod-create.patch
ro-bind-mounts-elevate-mnt-writers-for-vfs_unlink-callers.patch
ro-bind-mounts-do_rmdir-elevate-write-count.patch
ro-bind-mounts-elevate-writer-count-for-custom-struct-file.patch
ro-bind-mounts-honor-r-w-changes-at-do_remount-time.patch
page-owner-tracking-leak-detector.patch
x86-e820-debugging.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
