Remove fs.h from mm.h

Remove fs.h from mm.h. For this,
 1) Uninline vma_wants_writenotify(). It's pretty huge anyway.
 2) Add back fs.h or less bloated headers (err.h) to files that need it.

As result, on x86_64 allyesconfig, fs.h dependencies cut down from 3929 files
rebuilt down to 3444 (-12.3%).

Cross-compile tested without regressions on my two usual configs and (sigh):

alpha              arm-mx1ads        mips-bigsur          powerpc-ebony
alpha-allnoconfig  arm-neponset      mips-capcella        powerpc-g5
alpha-defconfig    arm-netwinder     mips-cobalt          powerpc-holly
alpha-up           arm-netx          mips-db1000          powerpc-iseries
arm                arm-ns9xxx        mips-db1100          powerpc-linkstation
arm-assabet        arm-omap_h2_1610  mips-db1200          powerpc-lite5200
arm-at91rm9200dk   arm-onearm        mips-db1500          powerpc-maple
arm-at91rm9200ek   arm-picotux200    mips-db1550          powerpc-mpc7448_hpc2
arm-at91sam9260ek  arm-pleb          mips-ddb5477         powerpc-mpc8272_ads
arm-at91sam9261ek  arm-pnx4008       mips-decstation      powerpc-mpc8313_rdb
arm-at91sam9263ek  arm-pxa255-idp    mips-e55             powerpc-mpc832x_mds
arm-at91sam9rlek   arm-realview      mips-emma2rh         powerpc-mpc832x_rdb
arm-ateb9200       arm-realview-smp  mips-excite          powerpc-mpc834x_itx
arm-badge4         arm-rpc           mips-fulong          powerpc-mpc834x_itxgp
arm-carmeva        arm-s3c2410       mips-ip22            powerpc-mpc834x_mds
arm-cerfcube       arm-shannon       mips-ip27            powerpc-mpc836x_mds
arm-clps7500       arm-shark         mips-ip32            powerpc-mpc8540_ads
arm-collie         arm-simpad        mips-jazz            powerpc-mpc8544_ds
arm-corgi          arm-spitz         mips-jmr3927         powerpc-mpc8560_ads
arm-csb337         arm-trizeps4      mips-malta           powerpc-mpc8568mds
arm-csb637         arm-versatile     mips-mipssim         powerpc-mpc85xx_cds
arm-ebsa110        i386              mips-mpc30x          powerpc-mpc8641_hpcn
arm-edb7211        i386-allnoconfig  mips-msp71xx         powerpc-mpc866_ads
arm-em_x270        i386-defconfig    mips-ocelot          powerpc-mpc885_ads
arm-ep93xx         i386-up           mips-pb1100          powerpc-pasemi
arm-footbridge     ia64              mips-pb1500          powerpc-pmac32
arm-fortunet       ia64-allnoconfig  mips-pb1550          powerpc-ppc64
arm-h3600          ia64-bigsur       mips-pnx8550-jbs     powerpc-prpmc2800
arm-h7201          ia64-defconfig    mips-pnx8550-stb810  powerpc-ps3
arm-h7202          ia64-gensparse    mips-qemu            powerpc-pseries
arm-hackkit        ia64-sim          mips-rbhma4200       powerpc-up
arm-integrator     ia64-sn2          mips-rbhma4500       s390
arm-iop13xx        ia64-tiger        mips-rm200           s390-allnoconfig
arm-iop32x         ia64-up           mips-sb1250-swarm    s390-defconfig
arm-iop33x         ia64-zx1          mips-sead            s390-up
arm-ixp2000        m68k              mips-tb0219          sparc
arm-ixp23xx        m68k-amiga        mips-tb0226          sparc-allnoconfig
arm-ixp4xx         m68k-apollo       mips-tb0287          sparc-defconfig
arm-jornada720     m68k-atari        mips-workpad         sparc-up
arm-kafa           m68k-bvme6000     mips-wrppmc          sparc64
arm-kb9202         m68k-hp300        mips-yosemite        sparc64-allnoconfig
arm-ks8695         m68k-mac          parisc               sparc64-defconfig
arm-lart           m68k-mvme147      parisc-allnoconfig   sparc64-up
arm-lpd270         m68k-mvme16x      parisc-defconfig     um-x86_64
arm-lpd7a400       m68k-q40          parisc-up            x86_64
arm-lpd7a404       m68k-sun3         powerpc              x86_64-allnoconfig
arm-lubbock        m68k-sun3x        powerpc-cell         x86_64-defconfig
arm-lusl7200       mips              powerpc-celleb       x86_64-up
arm-mainstone      mips-atlas        powerpc-chrp32

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 5 insertions, 33 deletions

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 49b7053043ad..e6a71c82d204 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -1,6 +1,8 @@
 #ifndef _LINUX_HUGETLB_H
 #define _LINUX_HUGETLB_H
 
+#include <linux/fs.h>
+
 #ifdef CONFIG_HUGETLB_PAGE
 
 #include <linux/mempolicy.h>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3e9e8fec5a41..655094dc9440 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -10,7 +10,6 @@
 #include <linux/mmzone.h>
 #include <linux/rbtree.h>
 #include <linux/prio_tree.h>
-#include <linux/fs.h>
 #include <linux/mutex.h>
 #include <linux/debug_locks.h>
 #include <linux/backing-dev.h>
@@ -18,7 +17,9 @@
 
 struct mempolicy;
 struct anon_vma;
+struct file_ra_state;
 struct user_struct;
+struct writeback_control;
 
 #ifndef CONFIG_DISCONTIGMEM          /* Don't use mapnrs, do it properly */
 extern unsigned long max_mapnr;
@@ -861,38 +862,7 @@ struct shrinker {
 extern void register_shrinker(struct shrinker *);
 extern void unregister_shrinker(struct shrinker *);
 
-/*
- * Some shared mappigns will want the pages marked read-only
- * to track write events. If so, we'll downgrade vm_page_prot
- * to the private version (using protection_map[] without the
- * VM_SHARED bit).
- */
-static inline int vma_wants_writenotify(struct vm_area_struct *vma)
-{
-        unsigned int vm_flags = vma->vm_flags;
-
-        /* If it was private or non-writable, the write bit is already clear */
-        if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED)))
-                return 0;
-
-        /* The backer wishes to know when pages are first written to? */
-        if (vma->vm_ops && vma->vm_ops->page_mkwrite)
-                return 1;
-
-        /* The open routine did something to the protections already? */
-        if (pgprot_val(vma->vm_page_prot) !=
-            pgprot_val(protection_map[vm_flags &
-                    (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]))
-                return 0;
-
-        /* Specialty mapping? */
-        if (vm_flags & (VM_PFNMAP|VM_INSERTPAGE))
-                return 0;
-
-        /* Can the mapping track the dirty pages? */
-        return vma->vm_file && vma->vm_file->f_mapping &&
-                mapping_cap_account_dirty(vma->vm_file->f_mapping);
-}
+int vma_wants_writenotify(struct vm_area_struct *vma);
 
 extern pte_t *FASTCALL(get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl));