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| author | Coleman Kane <ckane@colemankane.org> | 2021-07-26 13:55:55 -0400 |
|---|---|---|
| committer | Tony Hutter <hutter2@llnl.gov> | 2021-09-22 15:19:08 -0700 |
| commit | 6b9d0eda7573b68e0a6e0e1e972fb3b6e2c00804 (patch) | |
| tree | 93cc2f5c9271b286c978ed2496418f764003af1a | |
| parent | 744cdfd93b9e4d4e8ccc445cdc7371164b1a3bed (diff) | |
Linux 5.14 compat: explicity assign set_page_dirty
Kernel 5.14 introduced a change where set_page_dirty of
struct address_space_operations is no longer implicitly set to
__set_page_dirty_buffers(), which ended up resulting in a NULL
pointer deref in the kernel when it is attempted to be called.
This change sets .set_page_dirty in the structure to
__set_page_dirty_nobuffers(), which was introduced with the
related patch set. The breaking change was introduce in commit
0af573780b0b13fceb7fabd49dc1b073cee9a507 to torvalds/linux.git.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Coleman Kane <ckane@colemankane.org>
Closes #12427
| -rw-r--r-- | config/kernel-vfs-set_page_dirty.m4 | 34 | ||||
| -rw-r--r-- | config/kernel.m4 | 2 | ||||
| -rw-r--r-- | module/os/linux/zfs/zpl_file.c | 6 |
3 files changed, 42 insertions, 0 deletions
diff --git a/config/kernel-vfs-set_page_dirty.m4 b/config/kernel-vfs-set_page_dirty.m4 new file mode 100644 index 000000000..a9d252e4e --- /dev/null +++ b/config/kernel-vfs-set_page_dirty.m4 @@ -0,0 +1,34 @@ +dnl # +dnl # Linux 5.14 adds a change to require set_page_dirty to be manually +dnl # wired up in struct address_space_operations. Determine if this needs +dnl # to be done. This patch set also introduced __set_page_dirty_nobuffers +dnl # declaration in linux/pagemap.h, so these tests look for the presence +dnl # of that function to tell the compiler to assign set_page_dirty in +dnl # module/os/linux/zfs/zpl_file.c +dnl # +AC_DEFUN([ZFS_AC_KERNEL_SRC_VFS_SET_PAGE_DIRTY_NOBUFFERS], [ + ZFS_LINUX_TEST_SRC([vfs_has_set_page_dirty_nobuffers], [ + #include <linux/pagemap.h> + #include <linux/fs.h> + + static const struct address_space_operations + aops __attribute__ ((unused)) = { + .set_page_dirty = __set_page_dirty_nobuffers, + }; + ],[]) +]) + +AC_DEFUN([ZFS_AC_KERNEL_VFS_SET_PAGE_DIRTY_NOBUFFERS], [ + dnl # + dnl # Linux 5.14 change requires set_page_dirty() to be assigned + dnl # in address_space_operations() + dnl # + AC_MSG_CHECKING([__set_page_dirty_nobuffers exists]) + ZFS_LINUX_TEST_RESULT([vfs_has_set_page_dirty_nobuffers], [ + AC_MSG_RESULT([yes]) + AC_DEFINE(HAVE_VFS_SET_PAGE_DIRTY_NOBUFFERS, 1, + [__set_page_dirty_nobuffers exists]) + ],[ + AC_MSG_RESULT([no]) + ]) +]) diff --git a/config/kernel.m4 b/config/kernel.m4 index c66c3a405..3433a300a 100644 --- a/config/kernel.m4 +++ b/config/kernel.m4 @@ -131,6 +131,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [ ZFS_AC_KERNEL_SRC_SIGNAL_STOP ZFS_AC_KERNEL_SRC_SIGINFO ZFS_AC_KERNEL_SRC_SET_SPECIAL_STATE + ZFS_AC_KERNEL_SRC_VFS_SET_PAGE_DIRTY_NOBUFFERS AC_MSG_CHECKING([for available kernel interfaces]) ZFS_LINUX_TEST_COMPILE_ALL([kabi]) @@ -235,6 +236,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [ ZFS_AC_KERNEL_SIGNAL_STOP ZFS_AC_KERNEL_SIGINFO ZFS_AC_KERNEL_SET_SPECIAL_STATE + ZFS_AC_KERNEL_VFS_SET_PAGE_DIRTY_NOBUFFERS ]) dnl # diff --git a/module/os/linux/zfs/zpl_file.c b/module/os/linux/zfs/zpl_file.c index 10a07f327..cd54c40ac 100644 --- a/module/os/linux/zfs/zpl_file.c +++ b/module/os/linux/zfs/zpl_file.c @@ -33,6 +33,9 @@ #include <sys/zfs_vfsops.h> #include <sys/zfs_vnops.h> #include <sys/zfs_project.h> +#ifdef HAVE_VFS_SET_PAGE_DIRTY_NOBUFFERS +#include <linux/pagemap.h> +#endif /* * When using fallocate(2) to preallocate space, inflate the requested @@ -1007,6 +1010,9 @@ const struct address_space_operations zpl_address_space_operations = { .writepage = zpl_writepage, .writepages = zpl_writepages, .direct_IO = zpl_direct_IO, +#ifdef HAVE_VFS_SET_PAGE_DIRTY_NOBUFFERS + .set_page_dirty = __set_page_dirty_nobuffers, +#endif }; const struct file_operations zpl_file_operations = { |