Linux 4.12 compat: super_setup_bdi_name()

All filesystems were converted to dynamically allocated BDIs.  The
destruction of backing_dev_info structures is handled as part of
super block destruction.  Refactor the code to abstract away the
details of creating and destroying a BDI.

Reviewed-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6089

diff --git a/config/kernel-bdi-setup-and-register.m4 b/config/kernel-bdi-setup-and-register.m4
deleted file mode 100644 (file)
index d1062e1..0000000
--- a/config/kernel-bdi-setup-and-register.m4
+++ /dev/null
@@ -1,38 +0,0 @@
-dnl #
-dnl # 2.6.32 - 2.6.33, bdi_setup_and_register() is not exported.
-dnl # 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
-dnl # 4.0 - x.y, bdi_setup_and_register() takes 2 arguments.
-dnl #
-AC_DEFUN([ZFS_AC_KERNEL_BDI_SETUP_AND_REGISTER], [
-       AC_MSG_CHECKING([whether bdi_setup_and_register() wants 2 args])
-       ZFS_LINUX_TRY_COMPILE_SYMBOL([
-               #include <linux/backing-dev.h>
-               struct backing_dev_info bdi;
-       ], [
-               char *name = "bdi";
-               int error __attribute__((unused)) =
-                   bdi_setup_and_register(&bdi, name);
-       ], [bdi_setup_and_register], [mm/backing-dev.c], [
-               AC_MSG_RESULT(yes)
-               AC_DEFINE(HAVE_2ARGS_BDI_SETUP_AND_REGISTER, 1,
-                   [bdi_setup_and_register() wants 2 args])
-       ], [
-               AC_MSG_RESULT(no)
-               AC_MSG_CHECKING([whether bdi_setup_and_register() wants 3 args])
-               ZFS_LINUX_TRY_COMPILE_SYMBOL([
-                       #include <linux/backing-dev.h>
-                       struct backing_dev_info bdi;
-               ], [
-                       char *name = "bdi";
-                       unsigned int cap = BDI_CAP_MAP_COPY;
-                       int error __attribute__((unused)) =
-                           bdi_setup_and_register(&bdi, name, cap);
-               ], [bdi_setup_and_register], [mm/backing-dev.c], [
-                       AC_MSG_RESULT(yes)
-                       AC_DEFINE(HAVE_3ARGS_BDI_SETUP_AND_REGISTER, 1,
-                           [bdi_setup_and_register() wants 3 args])
-               ], [
-                       AC_MSG_RESULT(no)
-               ])
-       ])
-])

diff --git a/config/kernel-bdi.m4 b/config/kernel-bdi.m4
new file mode 100644 (file)
index 0000000..c2a9dd2
--- /dev/null
+++ b/config/kernel-bdi.m4
@@ -0,0 +1,56 @@
+dnl #
+dnl # 2.6.32 - 2.6.33, bdi_setup_and_register() is not exported.
+dnl # 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
+dnl # 4.0 - 4.11, bdi_setup_and_register() takes 2 arguments.
+dnl # 4.12 - x.y, super_setup_bdi_name() new interface.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_BDI], [
+       AC_MSG_CHECKING([whether super_setup_bdi_name() exists])
+       ZFS_LINUX_TRY_COMPILE_SYMBOL([
+               #include <linux/fs.h>
+               struct super_block sb;
+       ], [
+               char *name = "bdi";
+               int error __attribute__((unused)) =
+                   super_setup_bdi_name(&sb, name);
+       ], [super_setup_bdi_name], [fs/super.c], [
+               AC_MSG_RESULT(yes)
+               AC_DEFINE(HAVE_SUPER_SETUP_BDI_NAME, 1,
+                    [super_setup_bdi_name() exits])
+       ], [
+               AC_MSG_RESULT(no)
+               AC_MSG_CHECKING(
+                   [whether bdi_setup_and_register() wants 2 args])
+               ZFS_LINUX_TRY_COMPILE_SYMBOL([
+                       #include <linux/backing-dev.h>
+                       struct backing_dev_info bdi;
+               ], [
+                       char *name = "bdi";
+                       int error __attribute__((unused)) =
+                           bdi_setup_and_register(&bdi, name);
+               ], [bdi_setup_and_register], [mm/backing-dev.c], [
+                       AC_MSG_RESULT(yes)
+                       AC_DEFINE(HAVE_2ARGS_BDI_SETUP_AND_REGISTER, 1,
+                           [bdi_setup_and_register() wants 2 args])
+               ], [
+                       AC_MSG_RESULT(no)
+                       AC_MSG_CHECKING(
+                           [whether bdi_setup_and_register() wants 3 args])
+                       ZFS_LINUX_TRY_COMPILE_SYMBOL([
+                               #include <linux/backing-dev.h>
+                               struct backing_dev_info bdi;
+                       ], [
+                               char *name = "bdi";
+                               unsigned int cap = BDI_CAP_MAP_COPY;
+                               int error __attribute__((unused)) =
+                                   bdi_setup_and_register(&bdi, name, cap);
+                       ], [bdi_setup_and_register], [mm/backing-dev.c], [
+                               AC_MSG_RESULT(yes)
+                               AC_DEFINE(HAVE_3ARGS_BDI_SETUP_AND_REGISTER, 1,
+                                   [bdi_setup_and_register() wants 3 args])
+                       ], [
+                               AC_MSG_RESULT(no)
+                       ])
+               ])
+       ])
+])

diff --git a/config/kernel.m4 b/config/kernel.m4
index 71c88aa36cef78ecaf8aff224f3ac6ffdc76c3c2..638d9e143bba8bae23cac6a1d05209c77f7b88c8 100644 (file)
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -100,7 +100,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
        ZFS_AC_KERNEL_SHRINK_CONTROL_HAS_NID
        ZFS_AC_KERNEL_S_INSTANCES_LIST_HEAD
        ZFS_AC_KERNEL_S_D_OP
-       ZFS_AC_KERNEL_BDI_SETUP_AND_REGISTER
+       ZFS_AC_KERNEL_BDI
        ZFS_AC_KERNEL_SET_NLINK
        ZFS_AC_KERNEL_ELEVATOR_CHANGE
        ZFS_AC_KERNEL_5ARG_SGET

diff --git a/include/linux/vfs_compat.h b/include/linux/vfs_compat.h
index cd22b522ab79d7b93652011bf861eb0f40fe6321..4e61b1d0901795f219ce223e53d80d4518465eb0 100644 (file)
--- a/include/linux/vfs_compat.h
+++ b/include/linux/vfs_compat.h
@@ -70,45 +70,114 @@ truncate_setsize(struct inode *ip, loff_t new)
 /*
  * 2.6.32 - 2.6.33, bdi_setup_and_register() is not available.
  * 2.6.34 - 3.19, bdi_setup_and_register() takes 3 arguments.
- * 4.0 - x.y, bdi_setup_and_register() takes 2 arguments.
+ * 4.0 - 4.11, bdi_setup_and_register() takes 2 arguments.
+ * 4.12 - x.y, super_setup_bdi_name() new interface.
  */
-#if defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER)
+#if defined(HAVE_SUPER_SETUP_BDI_NAME)
 static inline int
-zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
+zpl_bdi_setup(struct super_block *sb, char *name)
 {
-       return (bdi_setup_and_register(bdi, name));
+       return (super_setup_bdi_name(sb, name));
+}
+static inline void
+zpl_bdi_destroy(struct super_block *sb)
+{
+}
+#elif defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER)
+static inline int
+zpl_bdi_setup(struct super_block *sb, char *name)
+{
+       struct backing_dev_info *bdi;
+       int error;
+
+       bdi = kmem_zalloc(sizeof (struct backing_dev_info), KM_SLEEP);
+       error = bdi_setup_and_register(bdi, name);
+       if (error) {
+               kmem_free(bdi, sizeof (struct backing_dev_info));
+               return (error);
+       }
+
+       sb->s_bdi = bdi;
+
+       return (0);
+}
+static inline void
+zpl_bdi_destroy(struct super_block *sb)
+{
+       struct backing_dev_info *bdi = sb->s_bdi;
+
+       bdi_destroy(bdi);
+       kmem_free(bdi, sizeof (struct backing_dev_info));
+       sb->s_bdi = NULL;
 }
 #elif defined(HAVE_3ARGS_BDI_SETUP_AND_REGISTER)
 static inline int
-zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
+zpl_bdi_setup(struct super_block *sb, char *name)
 {
-       return (bdi_setup_and_register(bdi, name, BDI_CAP_MAP_COPY));
+       struct backing_dev_info *bdi;
+       int error;
+
+       bdi = kmem_zalloc(sizeof (struct backing_dev_info), KM_SLEEP);
+       error = bdi_setup_and_register(bdi, name, BDI_CAP_MAP_COPY);
+       if (error) {
+               kmem_free(sb->s_bdi, sizeof (struct backing_dev_info));
+               return (error);
+       }
+
+       sb->s_bdi = bdi;
+
+       return (0);
+}
+static inline void
+zpl_bdi_destroy(struct super_block *sb)
+{
+       struct backing_dev_info *bdi = sb->s_bdi;
+
+       bdi_destroy(bdi);
+       kmem_free(bdi, sizeof (struct backing_dev_info));
+       sb->s_bdi = NULL;
 }
 #else
 extern atomic_long_t zfs_bdi_seq;
 
 static inline int
-zpl_bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
+zpl_bdi_setup(struct super_block *sb, char *name)
 {
+       struct backing_dev_info *bdi;
        char tmp[32];
        int error;
 
+       bdi = kmem_zalloc(sizeof (struct backing_dev_info), KM_SLEEP);
        bdi->name = name;
        bdi->capabilities = BDI_CAP_MAP_COPY;
 
        error = bdi_init(bdi);
-       if (error)
+       if (error) {
+               kmem_free(bdi, sizeof (struct backing_dev_info));
                return (error);
+       }
 
        sprintf(tmp, "%.28s%s", name, "-%d");
        error = bdi_register(bdi, NULL, tmp,
            atomic_long_inc_return(&zfs_bdi_seq));
        if (error) {
                bdi_destroy(bdi);
+               kmem_free(bdi, sizeof (struct backing_dev_info));
                return (error);
        }
 
-       return (error);
+       sb->s_bdi = bdi;
+
+       return (0);
+}
+static inline void
+zpl_bdi_destroy(struct super_block *sb)
+{
+       struct backing_dev_info *bdi = sb->s_bdi;
+
+       bdi_destroy(bdi);
+       kmem_free(bdi, sizeof (struct backing_dev_info));
+       sb->s_bdi = NULL;
 }
 #endif
 

diff --git a/include/sys/zfs_vfsops.h b/include/sys/zfs_vfsops.h
index aeecc472dabcb0290b842cfc0b7e4d30dc015fa6..2326da42218315629b9e7caeca08a9c1af70515b 100644 (file)
--- a/include/sys/zfs_vfsops.h
+++ b/include/sys/zfs_vfsops.h
@@ -75,7 +75,6 @@ typedef struct zfs_mnt {
 struct zfsvfs {
        vfs_t           *z_vfs;         /* generic fs struct */
        struct super_block *z_sb;       /* generic super_block */
-       struct backing_dev_info z_bdi;  /* generic backing dev info */
        struct zfsvfs   *z_parent;      /* parent fs */
        objset_t        *z_os;          /* objset reference */
        uint64_t        z_flags;        /* super_block flags */

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
index 40fd5f7648d5f808339ae2bb0081db46541a6842..15cadcad5123096de2d1673e49daa1a0d56641b1 100644 (file)
--- a/module/zfs/zfs_vfsops.c
+++ b/module/zfs/zfs_vfsops.c
@@ -1568,7 +1568,8 @@ zfsvfs_teardown(zfsvfs_t *zfsvfs, boolean_t unmounting)
        return (0);
 }
 
-#if !defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER) && \
+#if !defined(HAVE_SUPER_SETUP_BDI_NAME) && \
+       !defined(HAVE_2ARGS_BDI_SETUP_AND_REGISTER) && \
        !defined(HAVE_3ARGS_BDI_SETUP_AND_REGISTER)
 atomic_long_t zfs_bdi_seq = ATOMIC_LONG_INIT(0);
 #endif
@@ -1605,13 +1606,13 @@ zfs_domount(struct super_block *sb, zfs_mnt_t *zm, int silent)
        sb->s_time_gran = 1;
        sb->s_blocksize = recordsize;
        sb->s_blocksize_bits = ilog2(recordsize);
-       zfsvfs->z_bdi.ra_pages = 0;
-       sb->s_bdi = &zfsvfs->z_bdi;
 
-       error = -zpl_bdi_setup_and_register(&zfsvfs->z_bdi, "zfs");
+       error = -zpl_bdi_setup(sb, "zfs");
        if (error)
                goto out;
 
+       sb->s_bdi->ra_pages = 0;
+
        /* Set callback operations for the file system. */
        sb->s_op = &zpl_super_operations;
        sb->s_xattr = zpl_xattr_handlers;
@@ -1732,7 +1733,7 @@ zfs_umount(struct super_block *sb)
        arc_remove_prune_callback(zfsvfs->z_arc_prune);
        VERIFY(zfsvfs_teardown(zfsvfs, B_TRUE) == 0);
        os = zfsvfs->z_os;
-       bdi_destroy(sb->s_bdi);
+       zpl_bdi_destroy(sb);
 
        /*
         * z_os will be NULL if there was an error in