Re: dio_get_page() lockdep complaints


On Fri, 2007-11-09 at 12:45 -0500, Trond Myklebust wrote:
On Fri, 2007-11-09 at 09:30 -0800, Zach Brown wrote:
So, reiserfs and NFS are nesting i_mutex inside the mmap_sem.

[<b038c6e5>] mutex_lock+0x1c/0x1f
[<b01b17e9>] reiserfs_file_release+0x54/0x447
[<b016afe7>] __fput+0x53/0x101
[<b016b0ee>] fput+0x19/0x1c
[<b015bcd5>] remove_vma+0x3b/0x4d
[<b015c659>] do_munmap+0x17f/0x1cf

[<ffffffff802686a1>] _mutex_lock+0x28/0x34
[<ffffffff883e71d0>] nfs_revalidate_mapping+0x6d/0xac [nfs]
[<ffffffff883e4b51>] nfs_file_mmap+0x5c/0x74 [nfs]
[<ffffffff8020df7e>] do_mmap_pgoff+0x51a/0x817
[<ffffffff80225d19>] sys_mmap+0x90/0x119

I think i_mutex is fundamentally nested outside of the mmap_sem because
of faulting in the buffered write path. I think these warnings could be
reproduced with a careful test app which tries buffered writes from an
address which will fault.

DIO just tripped it up because it *always* performs get_user_pages() on
the memory.

So reiser and NFS need to be fixed. No?

Actually, it is rather mmap() needs to be fixed. It is cold calling the
filesystem while holding all sorts of nasty locks. It needs to be
migrated to the same sort of syscall layout as read() and write().

You _first_ call the filesystem so that it can make whatever
preparations it needs outside the lock. The filesystem then calls the
VM, which can then call the filesystem back if needed.

Right, which gets us into all kinds of trouble because some sites need
mmap_sem to resolve some races, notably s390 31-bit and shm.

Quick proto-type that moves mmap_sem into do_mmap{,_pgoff} and provides
_locked functions for those few icky sites.

The !_locked functions also call f_op->mmap_prepare() before taking the
mmap_sem. Which makes for some ugly asymetry :-/

Anyway, I'm not comming up with anything nicer atm, hopefully a nice
idea will present itself soon.

(compile tested only - mostly for illustrational purposes)

Not-signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
arch/alpha/kernel/osf_sys.c | 2 -
arch/arm/kernel/sys_arm.c | 2 -
arch/avr32/kernel/sys_avr32.c | 2 -
arch/blackfin/kernel/sys_bfin.c | 2 -
arch/cris/kernel/sys_cris.c | 2 -
arch/frv/kernel/sys_frv.c | 4 --
arch/h8300/kernel/sys_h8300.c | 4 --
arch/ia64/ia32/sys_ia32.c | 30 +++++-----------
arch/ia64/kernel/sys_ia64.c | 2 -
arch/m32r/kernel/sys_m32r.c | 2 -
arch/m68k/kernel/sys_m68k.c | 4 --
arch/m68knommu/kernel/sys_m68k.c | 2 -
arch/mips/kernel/irixelf.c | 10 -----
arch/mips/kernel/linux32.c | 2 -
arch/mips/kernel/syscall.c | 2 -
arch/mips/kernel/sysirix.c | 5 --
arch/parisc/kernel/sys_parisc.c | 2 -
arch/powerpc/kernel/syscalls.c | 2 -
arch/s390/kernel/compat_linux.c | 5 +-
arch/s390/kernel/sys_s390.c | 2 -
arch/sh/kernel/sys_sh.c | 2 -
arch/sh64/kernel/sys_sh64.c | 2 -
arch/sparc/kernel/sys_sparc.c | 2 -
arch/sparc/kernel/sys_sunos.c | 2 -
arch/sparc64/kernel/binfmt_aout32.c | 6 ---
arch/sparc64/kernel/sys_sparc.c | 2 -
arch/sparc64/kernel/sys_sunos32.c | 2 -
arch/sparc64/solaris/misc.c | 2 -
arch/um/kernel/syscall.c | 2 -
arch/v850/kernel/syscalls.c | 2 -
arch/x86/ia32/ia32_aout.c | 6 ---
arch/x86/ia32/sys_ia32.c | 5 --
arch/x86/kernel/sys_i386_32.c | 2 -
arch/x86/kernel/sys_x86_64.c | 2 -
arch/xtensa/kernel/syscall.c | 2 -
drivers/char/drm/drm_bufs.c | 4 --
drivers/char/drm/i810_dma.c | 2 -
fs/aio.c | 4 +-
fs/binfmt_aout.c | 6 ---
fs/binfmt_elf.c | 6 ---
fs/binfmt_elf_fdpic.c | 9 ----
fs/binfmt_flat.c | 6 +--
fs/binfmt_som.c | 6 ---
fs/nfs/file.c | 25 +++++++++----
include/linux/fs.h | 1
include/linux/mm.h | 13 ++++++-
ipc/shm.c | 2 -
mm/mmap.c | 65 +++++++++++++++++++++++++++++++++---
48 files changed, 109 insertions(+), 169 deletions(-)

Index: linux-2.6-2/arch/alpha/kernel/osf_sys.c
===================================================================
--- linux-2.6-2.orig/arch/alpha/kernel/osf_sys.c
+++ linux-2.6-2/arch/alpha/kernel/osf_sys.c
@@ -193,9 +193,7 @@ osf_mmap(unsigned long addr, unsigned lo
goto out;
}
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
- down_write(&current->mm->mmap_sem);
ret = do_mmap(file, addr, len, prot, flags, off);
- up_write(&current->mm->mmap_sem);
if (file)
fput(file);
out:
Index: linux-2.6-2/arch/arm/kernel/sys_arm.c
===================================================================
--- linux-2.6-2.orig/arch/arm/kernel/sys_arm.c
+++ linux-2.6-2/arch/arm/kernel/sys_arm.c
@@ -72,9 +72,7 @@ inline long do_mmap2(
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/avr32/kernel/sys_avr32.c
===================================================================
--- linux-2.6-2.orig/arch/avr32/kernel/sys_avr32.c
+++ linux-2.6-2/arch/avr32/kernel/sys_avr32.c
@@ -41,9 +41,7 @@ asmlinkage long sys_mmap2(unsigned long
return error;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, offset);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/blackfin/kernel/sys_bfin.c
===================================================================
--- linux-2.6-2.orig/arch/blackfin/kernel/sys_bfin.c
+++ linux-2.6-2/arch/blackfin/kernel/sys_bfin.c
@@ -78,9 +78,7 @@ do_mmap2(unsigned long addr, unsigned lo
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/cris/kernel/sys_cris.c
===================================================================
--- linux-2.6-2.orig/arch/cris/kernel/sys_cris.c
+++ linux-2.6-2/arch/cris/kernel/sys_cris.c
@@ -60,9 +60,7 @@ do_mmap2(unsigned long addr, unsigned lo
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/frv/kernel/sys_frv.c
===================================================================
--- linux-2.6-2.orig/arch/frv/kernel/sys_frv.c
+++ linux-2.6-2/arch/frv/kernel/sys_frv.c
@@ -69,9 +69,7 @@ asmlinkage long sys_mmap2(unsigned long

pgoff >>= (PAGE_SHIFT - 12);

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
@@ -114,9 +112,7 @@ asmlinkage long sys_mmap64(struct mmap_a
}
a.flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, a.addr, a.len, a.prot, a.flags, pgoff);
- up_write(&current->mm->mmap_sem);
if (file)
fput(file);
out:
Index: linux-2.6-2/arch/h8300/kernel/sys_h8300.c
===================================================================
--- linux-2.6-2.orig/arch/h8300/kernel/sys_h8300.c
+++ linux-2.6-2/arch/h8300/kernel/sys_h8300.c
@@ -60,9 +60,7 @@ static inline long do_mmap2(
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
@@ -147,9 +145,7 @@ asmlinkage long sys_mmap64(struct mmap_a
}
a.flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, a.addr, a.len, a.prot, a.flags, pgoff);
- up_write(&current->mm->mmap_sem);
if (file)
fput(file);
out:
Index: linux-2.6-2/arch/ia64/ia32/sys_ia32.c
===================================================================
--- linux-2.6-2.orig/arch/ia64/ia32/sys_ia32.c
+++ linux-2.6-2/arch/ia64/ia32/sys_ia32.c
@@ -212,12 +212,8 @@ mmap_subpage (struct file *file, unsigne
if (old_prot)
copy_from_user(page, (void __user *) PAGE_START(start), PAGE_SIZE);

- down_write(&current->mm->mmap_sem);
- {
- ret = do_mmap(NULL, PAGE_START(start), PAGE_SIZE, prot | PROT_WRITE,
- flags | MAP_FIXED | MAP_ANONYMOUS, 0);
- }
- up_write(&current->mm->mmap_sem);
+ ret = do_mmap(NULL, PAGE_START(start), PAGE_SIZE, prot | PROT_WRITE,
+ flags | MAP_FIXED | MAP_ANONYMOUS, 0);

if (IS_ERR((void *) ret))
goto out;
@@ -821,16 +817,14 @@ emulate_mmap (struct file *file, unsigne
DBG("mmap_body: mapping [0x%lx-0x%lx) %s with poff 0x%llx\n", pstart, pend,
is_congruent ? "congruent" : "not congruent", poff);

- down_write(&current->mm->mmap_sem);
- {
- if (!(flags & MAP_ANONYMOUS) && is_congruent)
- ret = do_mmap(file, pstart, pend - pstart, prot, flags | MAP_FIXED, poff);
- else
- ret = do_mmap(NULL, pstart, pend - pstart,
- prot | ((flags & MAP_ANONYMOUS) ? 0 : PROT_WRITE),
- flags | MAP_FIXED | MAP_ANONYMOUS, 0);
+ if (!(flags & MAP_ANONYMOUS) && is_congruent) {
+ ret = do_mmap(file, pstart, pend - pstart, prot,
+ flags | MAP_FIXED, poff);
+ } else {
+ ret = do_mmap(NULL, pstart, pend - pstart,
+ prot | ((flags & MAP_ANONYMOUS) ? 0 : PROT_WRITE),
+ flags | MAP_FIXED | MAP_ANONYMOUS, 0);
}
- up_write(&current->mm->mmap_sem);

if (IS_ERR((void *) ret))
return ret;
@@ -904,11 +898,7 @@ ia32_do_mmap (struct file *file, unsigne
}
mutex_unlock(&ia32_mmap_mutex);
#else
- down_write(&current->mm->mmap_sem);
- {
- addr = do_mmap(file, addr, len, prot, flags, offset);
- }
- up_write(&current->mm->mmap_sem);
+ addr = do_mmap(file, addr, len, prot, flags, offset);
#endif
DBG("ia32_do_mmap: returning 0x%lx\n", addr);
return addr;
Index: linux-2.6-2/arch/ia64/kernel/sys_ia64.c
===================================================================
--- linux-2.6-2.orig/arch/ia64/kernel/sys_ia64.c
+++ linux-2.6-2/arch/ia64/kernel/sys_ia64.c
@@ -209,9 +209,7 @@ do_mmap2 (unsigned long addr, unsigned l
goto out;
}

- down_write(&current->mm->mmap_sem);
addr = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

out: if (file)
fput(file);
Index: linux-2.6-2/arch/m32r/kernel/sys_m32r.c
===================================================================
--- linux-2.6-2.orig/arch/m32r/kernel/sys_m32r.c
+++ linux-2.6-2/arch/m32r/kernel/sys_m32r.c
@@ -110,9 +110,7 @@ asmlinkage long sys_mmap2(unsigned long
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/m68k/kernel/sys_m68k.c
===================================================================
--- linux-2.6-2.orig/arch/m68k/kernel/sys_m68k.c
+++ linux-2.6-2/arch/m68k/kernel/sys_m68k.c
@@ -63,9 +63,7 @@ static inline long do_mmap2(
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
@@ -150,9 +148,7 @@ asmlinkage long sys_mmap64(struct mmap_a
}
a.flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, a.addr, a.len, a.prot, a.flags, pgoff);
- up_write(&current->mm->mmap_sem);
if (file)
fput(file);
out:
Index: linux-2.6-2/arch/m68knommu/kernel/sys_m68k.c
===================================================================
--- linux-2.6-2.orig/arch/m68knommu/kernel/sys_m68k.c
+++ linux-2.6-2/arch/m68knommu/kernel/sys_m68k.c
@@ -61,9 +61,7 @@ static inline long do_mmap2(
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/mips/kernel/irixelf.c
===================================================================
--- linux-2.6-2.orig/arch/mips/kernel/irixelf.c
+++ linux-2.6-2/arch/mips/kernel/irixelf.c
@@ -342,12 +342,10 @@ static unsigned int load_irix_interp(str
(unsigned long)
(eppnt->p_offset & 0xfffff000));

- down_write(&current->mm->mmap_sem);
error = do_mmap(interpreter, vaddr,
eppnt->p_filesz + (eppnt->p_vaddr & 0xfff),
elf_prot, elf_type,
eppnt->p_offset & 0xfffff000);
- up_write(&current->mm->mmap_sem);

if (error < 0 && error > -1024) {
printk("Aieee IRIX interp mmap error=%d\n",
@@ -514,12 +512,10 @@ static inline void map_executable(struct
prot = (epp->p_flags & PF_R) ? PROT_READ : 0;
prot |= (epp->p_flags & PF_W) ? PROT_WRITE : 0;
prot |= (epp->p_flags & PF_X) ? PROT_EXEC : 0;
- down_write(&current->mm->mmap_sem);
(void) do_mmap(fp, (epp->p_vaddr & 0xfffff000),
(epp->p_filesz + (epp->p_vaddr & 0xfff)),
prot, EXEC_MAP_FLAGS,
(epp->p_offset & 0xfffff000));
- up_write(&current->mm->mmap_sem);

/* Fixup location tracking vars. */
if ((epp->p_vaddr & 0xfffff000) < *estack)
@@ -798,10 +794,8 @@ static int load_irix_binary(struct linux
* Since we do not have the power to recompile these, we
* emulate the SVr4 behavior. Sigh.
*/
- down_write(&current->mm->mmap_sem);
(void) do_mmap(NULL, 0, 4096, PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE, 0);
- up_write(&current->mm->mmap_sem);
#endif

start_thread(regs, elf_entry, bprm->p);
@@ -871,14 +865,12 @@ static int load_irix_library(struct file
while (elf_phdata->p_type != PT_LOAD) elf_phdata++;

/* Now use mmap to map the library into memory. */
- down_write(&current->mm->mmap_sem);
error = do_mmap(file,
elf_phdata->p_vaddr & 0xfffff000,
elf_phdata->p_filesz + (elf_phdata->p_vaddr & 0xfff),
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
elf_phdata->p_offset & 0xfffff000);
- up_write(&current->mm->mmap_sem);

k = elf_phdata->p_vaddr + elf_phdata->p_filesz;
if (k > elf_bss) elf_bss = k;
@@ -959,12 +951,10 @@ unsigned long irix_mapelf(int fd, struct
prot |= (flags & PF_W) ? PROT_WRITE : 0;
prot |= (flags & PF_X) ? PROT_EXEC : 0;

- down_write(&current->mm->mmap_sem);
retval = do_mmap(filp, (vaddr & 0xfffff000),
(filesz + (vaddr & 0xfff)),
prot, (MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE),
(offset & 0xfffff000));
- up_write(&current->mm->mmap_sem);

if (retval != (vaddr & 0xfffff000)) {
printk("irix_mapelf: do_mmap fails with %d!\n", retval);
Index: linux-2.6-2/arch/mips/kernel/linux32.c
===================================================================
--- linux-2.6-2.orig/arch/mips/kernel/linux32.c
+++ linux-2.6-2/arch/mips/kernel/linux32.c
@@ -119,9 +119,7 @@ sys32_mmap2(unsigned long addr, unsigned
}
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);
if (file)
fput(file);

Index: linux-2.6-2/arch/mips/kernel/syscall.c
===================================================================
--- linux-2.6-2.orig/arch/mips/kernel/syscall.c
+++ linux-2.6-2/arch/mips/kernel/syscall.c
@@ -136,9 +136,7 @@ do_mmap2(unsigned long addr, unsigned lo
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/mips/kernel/sysirix.c
===================================================================
--- linux-2.6-2.orig/arch/mips/kernel/sysirix.c
+++ linux-2.6-2/arch/mips/kernel/sysirix.c
@@ -1051,9 +1051,7 @@ asmlinkage unsigned long irix_mmap32(uns

flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

- down_write(&current->mm->mmap_sem);
retval = do_mmap(file, addr, len, prot, flags, offset);
- up_write(&current->mm->mmap_sem);
if (file)
fput(file);

@@ -1536,10 +1534,7 @@ asmlinkage int irix_mmap64(struct pt_reg

flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);
-
if (file)
fput(file);

Index: linux-2.6-2/arch/parisc/kernel/sys_parisc.c
===================================================================
--- linux-2.6-2.orig/arch/parisc/kernel/sys_parisc.c
+++ linux-2.6-2/arch/parisc/kernel/sys_parisc.c
@@ -137,9 +137,7 @@ static unsigned long do_mmap2(unsigned l

flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file != NULL)
fput(file);
Index: linux-2.6-2/arch/powerpc/kernel/syscalls.c
===================================================================
--- linux-2.6-2.orig/arch/powerpc/kernel/syscalls.c
+++ linux-2.6-2/arch/powerpc/kernel/syscalls.c
@@ -175,9 +175,7 @@ static inline unsigned long do_mmap2(uns

flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

- down_write(&current->mm->mmap_sem);
ret = do_mmap_pgoff(file, addr, len, prot, flags, off);
- up_write(&current->mm->mmap_sem);
if (file)
fput(file);
out:
Index: linux-2.6-2/arch/s390/kernel/compat_linux.c
===================================================================
--- linux-2.6-2.orig/arch/s390/kernel/compat_linux.c
+++ linux-2.6-2/arch/s390/kernel/compat_linux.c
@@ -860,14 +860,15 @@ static inline long do_mmap2(
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
if (!IS_ERR((void *) error) && error + len >= 0x80000000ULL) {
/* Result is out of bounds. */
+ /* XXX fix race - APZ */
+ down_write(&current->mm->mmap_sem);
do_munmap(current->mm, addr, len);
+ up_write(&current->mm->mmap_sem);
error = -ENOMEM;
}
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/s390/kernel/sys_s390.c
===================================================================
--- linux-2.6-2.orig/arch/s390/kernel/sys_s390.c
+++ linux-2.6-2/arch/s390/kernel/sys_s390.c
@@ -65,9 +65,7 @@ static inline long do_mmap2(
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/sh/kernel/sys_sh.c
===================================================================
--- linux-2.6-2.orig/arch/sh/kernel/sys_sh.c
+++ linux-2.6-2/arch/sh/kernel/sys_sh.c
@@ -153,9 +153,7 @@ do_mmap2(unsigned long addr, unsigned lo
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/sh64/kernel/sys_sh64.c
===================================================================
--- linux-2.6-2.orig/arch/sh64/kernel/sys_sh64.c
+++ linux-2.6-2/arch/sh64/kernel/sys_sh64.c
@@ -148,9 +148,7 @@ static inline long do_mmap2(
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/sparc/kernel/sys_sparc.c
===================================================================
--- linux-2.6-2.orig/arch/sparc/kernel/sys_sparc.c
+++ linux-2.6-2/arch/sparc/kernel/sys_sparc.c
@@ -252,9 +252,7 @@ static unsigned long do_mmap2(unsigned l
len = PAGE_ALIGN(len);
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

- down_write(&current->mm->mmap_sem);
retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/sparc/kernel/sys_sunos.c
===================================================================
--- linux-2.6-2.orig/arch/sparc/kernel/sys_sunos.c
+++ linux-2.6-2/arch/sparc/kernel/sys_sunos.c
@@ -120,9 +120,7 @@ asmlinkage unsigned long sunos_mmap(unsi
}

flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
- down_write(&current->mm->mmap_sem);
retval = do_mmap(file, addr, len, prot, flags, off);
- up_write(&current->mm->mmap_sem);
if (!ret_type)
retval = ((retval < PAGE_OFFSET) ? 0 : retval);

Index: linux-2.6-2/arch/sparc64/kernel/binfmt_aout32.c
===================================================================
--- linux-2.6-2.orig/arch/sparc64/kernel/binfmt_aout32.c
+++ linux-2.6-2/arch/sparc64/kernel/binfmt_aout32.c
@@ -290,24 +290,20 @@ static int load_aout32_binary(struct lin
goto beyond_if;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
fd_offset);
- up_write(&current->mm->mmap_sem);

if (error != N_TXTADDR(ex)) {
send_sig(SIGKILL, current, 0);
return error;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
fd_offset + ex.a_text);
- up_write(&current->mm->mmap_sem);
if (error != N_DATADDR(ex)) {
send_sig(SIGKILL, current, 0);
return error;
@@ -379,12 +375,10 @@ static int load_aout32_library(struct fi
start_addr = ex.a_entry & 0xfffff000;

/* Now use mmap to map the library into memory. */
- down_write(&current->mm->mmap_sem);
error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
N_TXTOFF(ex));
- up_write(&current->mm->mmap_sem);
retval = error;
if (error != start_addr)
goto out;
Index: linux-2.6-2/arch/sparc64/kernel/sys_sparc.c
===================================================================
--- linux-2.6-2.orig/arch/sparc64/kernel/sys_sparc.c
+++ linux-2.6-2/arch/sparc64/kernel/sys_sparc.c
@@ -576,9 +576,7 @@ asmlinkage unsigned long sys_mmap(unsign
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
len = PAGE_ALIGN(len);

- down_write(&current->mm->mmap_sem);
retval = do_mmap(file, addr, len, prot, flags, off);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/sparc64/kernel/sys_sunos32.c
===================================================================
--- linux-2.6-2.orig/arch/sparc64/kernel/sys_sunos32.c
+++ linux-2.6-2/arch/sparc64/kernel/sys_sunos32.c
@@ -99,12 +99,10 @@ asmlinkage u32 sunos_mmap(u32 addr, u32
flags &= ~_MAP_NEW;

flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
- down_write(&current->mm->mmap_sem);
retval = do_mmap(file,
(unsigned long) addr, (unsigned long) len,
(unsigned long) prot, (unsigned long) flags,
(unsigned long) off);
- up_write(&current->mm->mmap_sem);
if (!ret_type)
retval = ((retval < 0xf0000000) ? 0 : retval);
out_putf:
Index: linux-2.6-2/arch/sparc64/solaris/misc.c
===================================================================
--- linux-2.6-2.orig/arch/sparc64/solaris/misc.c
+++ linux-2.6-2/arch/sparc64/solaris/misc.c
@@ -95,12 +95,10 @@ static u32 do_solaris_mmap(u32 addr, u32
ret_type = flags & _MAP_NEW;
flags &= ~_MAP_NEW;

- down_write(&current->mm->mmap_sem);
flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
retval = do_mmap(file,
(unsigned long) addr, (unsigned long) len,
(unsigned long) prot, (unsigned long) flags, off);
- up_write(&current->mm->mmap_sem);
if(!ret_type)
retval = ((retval < STACK_TOP32) ? 0 : retval);

Index: linux-2.6-2/arch/um/kernel/syscall.c
===================================================================
--- linux-2.6-2.orig/arch/um/kernel/syscall.c
+++ linux-2.6-2/arch/um/kernel/syscall.c
@@ -54,9 +54,7 @@ long sys_mmap2(unsigned long addr, unsig
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/v850/kernel/syscalls.c
===================================================================
--- linux-2.6-2.orig/arch/v850/kernel/syscalls.c
+++ linux-2.6-2/arch/v850/kernel/syscalls.c
@@ -164,9 +164,7 @@ do_mmap2 (unsigned long addr, size_t len
goto out;
}

- down_write (&current->mm->mmap_sem);
ret = do_mmap_pgoff (file, addr, len, prot, flags, pgoff);
- up_write (&current->mm->mmap_sem);
if (file)
fput (file);
out:
Index: linux-2.6-2/arch/x86/ia32/ia32_aout.c
===================================================================
--- linux-2.6-2.orig/arch/x86/ia32/ia32_aout.c
+++ linux-2.6-2/arch/x86/ia32/ia32_aout.c
@@ -374,24 +374,20 @@ static int load_aout_binary(struct linux
goto beyond_if;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE | MAP_32BIT,
fd_offset);
- up_write(&current->mm->mmap_sem);

if (error != N_TXTADDR(ex)) {
send_sig(SIGKILL, current, 0);
return error;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE | MAP_32BIT,
fd_offset + ex.a_text);
- up_write(&current->mm->mmap_sem);
if (error != N_DATADDR(ex)) {
send_sig(SIGKILL, current, 0);
return error;
@@ -488,12 +484,10 @@ static int load_aout_library(struct file
goto out;
}
/* Now use mmap to map the library into memory. */
- down_write(&current->mm->mmap_sem);
error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_32BIT,
N_TXTOFF(ex));
- up_write(&current->mm->mmap_sem);
retval = error;
if (error != start_addr)
goto out;
Index: linux-2.6-2/arch/x86/ia32/sys_ia32.c
===================================================================
--- linux-2.6-2.orig/arch/x86/ia32/sys_ia32.c
+++ linux-2.6-2/arch/x86/ia32/sys_ia32.c
@@ -242,13 +242,10 @@ sys32_mmap(struct mmap_arg_struct __user
}

mm = current->mm;
- down_write(&mm->mmap_sem);
retval = do_mmap_pgoff(file, a.addr, a.len, a.prot, a.flags, a.offset>>PAGE_SHIFT);
if (file)
fput(file);

- up_write(&mm->mmap_sem);
-
return retval;
}

@@ -708,9 +705,7 @@ asmlinkage long sys32_mmap2(unsigned lon
return -EBADF;
}

- down_write(&mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/x86/kernel/sys_i386_32.c
===================================================================
--- linux-2.6-2.orig/arch/x86/kernel/sys_i386_32.c
+++ linux-2.6-2/arch/x86/kernel/sys_i386_32.c
@@ -54,9 +54,7 @@ asmlinkage long sys_mmap2(unsigned long
goto out;
}

- down_write(&mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/x86/kernel/sys_x86_64.c
===================================================================
--- linux-2.6-2.orig/arch/x86/kernel/sys_x86_64.c
+++ linux-2.6-2/arch/x86/kernel/sys_x86_64.c
@@ -51,9 +51,7 @@ asmlinkage long sys_mmap(unsigned long a
if (!file)
goto out;
}
- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, off >> PAGE_SHIFT);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/arch/xtensa/kernel/syscall.c
===================================================================
--- linux-2.6-2.orig/arch/xtensa/kernel/syscall.c
+++ linux-2.6-2/arch/xtensa/kernel/syscall.c
@@ -72,9 +72,7 @@ asmlinkage long xtensa_mmap2(unsigned lo
goto out;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
- up_write(&current->mm->mmap_sem);

if (file)
fput(file);
Index: linux-2.6-2/drivers/char/drm/drm_bufs.c
===================================================================
--- linux-2.6-2.orig/drivers/char/drm/drm_bufs.c
+++ linux-2.6-2/drivers/char/drm/drm_bufs.c
@@ -1517,18 +1517,14 @@ int drm_mapbufs(struct drm_device *dev,
retcode = -EINVAL;
goto done;
}
- down_write(&current->mm->mmap_sem);
virtual = do_mmap(file_priv->filp, 0, map->size,
PROT_READ | PROT_WRITE,
MAP_SHARED,
token);
- up_write(&current->mm->mmap_sem);
} else {
- down_write(&current->mm->mmap_sem);
virtual = do_mmap(file_priv->filp, 0, dma->byte_count,
PROT_READ | PROT_WRITE,
MAP_SHARED, 0);
- up_write(&current->mm->mmap_sem);
}
if (virtual > -1024UL) {
/* Real error */
Index: linux-2.6-2/drivers/char/drm/i810_dma.c
===================================================================
--- linux-2.6-2.orig/drivers/char/drm/i810_dma.c
+++ linux-2.6-2/drivers/char/drm/i810_dma.c
@@ -131,7 +131,6 @@ static int i810_map_buffer(struct drm_bu
if (buf_priv->currently_mapped == I810_BUF_MAPPED)
return -EINVAL;

- down_write(&current->mm->mmap_sem);
old_fops = file_priv->filp->f_op;
file_priv->filp->f_op = &i810_buffer_fops;
dev_priv->mmap_buffer = buf;
@@ -146,7 +145,6 @@ static int i810_map_buffer(struct drm_bu
retcode = PTR_ERR(buf_priv->virtual);
buf_priv->virtual = NULL;
}
- up_write(&current->mm->mmap_sem);

return retcode;
}
Index: linux-2.6-2/fs/aio.c
===================================================================
--- linux-2.6-2.orig/fs/aio.c
+++ linux-2.6-2/fs/aio.c
@@ -129,18 +129,18 @@ static int aio_setup_ring(struct kioctx

info->mmap_size = nr_pages * PAGE_SIZE;
dprintk("attempting mmap of %lu bytes\n", info->mmap_size);
- down_write(&ctx->mm->mmap_sem);
+ WARN_ON(ctx->mm != current->mm);
info->mmap_base = do_mmap(NULL, 0, info->mmap_size,
PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE,
0);
if (IS_ERR((void *)info->mmap_base)) {
- up_write(&ctx->mm->mmap_sem);
info->mmap_size = 0;
aio_free_ring(ctx);
return -EAGAIN;
}

dprintk("mmap address: 0x%08lx\n", info->mmap_base);
+ down_write(&ctx->mm->mmap_sem);
info->nr_pages = get_user_pages(current, ctx->mm,
info->mmap_base, nr_pages,
1, 0, info->ring_pages, NULL);
Index: linux-2.6-2/fs/binfmt_aout.c
===================================================================
--- linux-2.6-2.orig/fs/binfmt_aout.c
+++ linux-2.6-2/fs/binfmt_aout.c
@@ -403,24 +403,20 @@ static int load_aout_binary(struct linux
goto beyond_if;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
fd_offset);
- up_write(&current->mm->mmap_sem);

if (error != N_TXTADDR(ex)) {
send_sig(SIGKILL, current, 0);
return error;
}

- down_write(&current->mm->mmap_sem);
error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
fd_offset + ex.a_text);
- up_write(&current->mm->mmap_sem);
if (error != N_DATADDR(ex)) {
send_sig(SIGKILL, current, 0);
return error;
@@ -518,12 +514,10 @@ static int load_aout_library(struct file
goto out;
}
/* Now use mmap to map the library into memory. */
- down_write(&current->mm->mmap_sem);
error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
N_TXTOFF(ex));
- up_write(&current->mm->mmap_sem);
retval = error;
if (error != start_addr)
goto out;
Index: linux-2.6-2/fs/binfmt_elf.c
===================================================================
--- linux-2.6-2.orig/fs/binfmt_elf.c
+++ linux-2.6-2/fs/binfmt_elf.c
@@ -303,7 +303,6 @@ static unsigned long elf_map(struct file
unsigned long map_addr;
unsigned long pageoffset = ELF_PAGEOFFSET(eppnt->p_vaddr);

- down_write(&current->mm->mmap_sem);
/* mmap() will return -EINVAL if given a zero size, but a
* segment with zero filesize is perfectly valid */
if (eppnt->p_filesz + pageoffset)
@@ -312,7 +311,6 @@ static unsigned long elf_map(struct file
eppnt->p_offset - pageoffset);
else
map_addr = ELF_PAGESTART(addr);
- up_write(&current->mm->mmap_sem);
return(map_addr);
}

@@ -1026,10 +1024,8 @@ static int load_elf_binary(struct linux_
and some applications "depend" upon this behavior.
Since we do not have the power to recompile these, we
emulate the SVr4 behavior. Sigh. */
- down_write(&current->mm->mmap_sem);
error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
MAP_FIXED | MAP_PRIVATE, 0);
- up_write(&current->mm->mmap_sem);
}

#ifdef ELF_PLAT_INIT
@@ -1125,7 +1121,6 @@ static int load_elf_library(struct file
eppnt++;

/* Now use mmap to map the library into memory. */
- down_write(&current->mm->mmap_sem);
error = do_mmap(file,
ELF_PAGESTART(eppnt->p_vaddr),
(eppnt->p_filesz +
@@ -1134,7 +1129,6 @@ static int load_elf_library(struct file
MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
(eppnt->p_offset -
ELF_PAGEOFFSET(eppnt->p_vaddr)));
- up_write(&current->mm->mmap_sem);
if (error != ELF_PAGESTART(eppnt->p_vaddr))
goto out_free_ph;

Index: linux-2.6-2/fs/binfmt_elf_fdpic.c
===================================================================
--- linux-2.6-2.orig/fs/binfmt_elf_fdpic.c
+++ linux-2.6-2/fs/binfmt_elf_fdpic.c
@@ -370,14 +370,12 @@ static int load_elf_fdpic_binary(struct
if (stack_size < PAGE_SIZE * 2)
stack_size = PAGE_SIZE * 2;

- down_write(&current->mm->mmap_sem);
current->mm->start_brk = do_mmap(NULL, 0, stack_size,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
0);

if (IS_ERR_VALUE(current->mm->start_brk)) {
- up_write(&current->mm->mmap_sem);
retval = current->mm->start_brk;
current->mm->start_brk = 0;
goto error_kill;
@@ -385,6 +383,7 @@ static int load_elf_fdpic_binary(struct

/* expand the stack mapping to use up the entire allocation granule */
fullsize = ksize((char *) current->mm->start_brk);
+ down_write(&current->mm->mmap_sem);
if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
fullsize, 0, 0)))
stack_size = fullsize;
@@ -904,10 +903,8 @@ static int elf_fdpic_map_file_constdisp_
if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
mflags |= MAP_EXECUTABLE;

- down_write(&mm->mmap_sem);
maddr = do_mmap(NULL, load_addr, top - base,
PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
- up_write(&mm->mmap_sem);
if (IS_ERR_VALUE(maddr))
return (int) maddr;

@@ -1050,10 +1047,8 @@ static int elf_fdpic_map_file_by_direct_

/* create the mapping */
disp = phdr->p_vaddr & ~PAGE_MASK;
- down_write(&mm->mmap_sem);
maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
phdr->p_offset - disp);
- up_write(&mm->mmap_sem);

kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
loop, phdr->p_memsz + disp, prot, flags,
@@ -1096,10 +1091,8 @@ static int elf_fdpic_map_file_by_direct_
unsigned long xmaddr;

flags |= MAP_FIXED | MAP_ANONYMOUS;
- down_write(&mm->mmap_sem);
xmaddr = do_mmap(NULL, xaddr, excess - excess1,
prot, flags, 0);
- up_write(&mm->mmap_sem);

kdebug("mmap[%d] <anon>"
" ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
Index: linux-2.6-2/fs/binfmt_flat.c
===================================================================
--- linux-2.6-2.orig/fs/binfmt_flat.c
+++ linux-2.6-2/fs/binfmt_flat.c
@@ -531,9 +531,7 @@ static int load_flat_file(struct linux_b
*/
DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");

- down_write(&current->mm->mmap_sem);
textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0);
- up_write(&current->mm->mmap_sem);
if (!textpos || textpos >= (unsigned long) -4096) {
if (!textpos)
textpos = (unsigned long) -ENOMEM;
@@ -544,7 +542,7 @@ static int load_flat_file(struct linux_b

len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
down_write(&current->mm->mmap_sem);
- realdatastart = do_mmap(0, 0, len,
+ realdatastart = do_mmap_locked(0, 0, len,
PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
/* Remap to use all availabe slack region space */
if (realdatastart && (realdatastart < (unsigned long)-4096)) {
@@ -596,7 +594,7 @@ static int load_flat_file(struct linux_b

len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
down_write(&current->mm->mmap_sem);
- textpos = do_mmap(0, 0, len,
+ textpos = do_mmap_locked(0, 0, len,
PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
/* Remap to use all availabe slack region space */
if (textpos && (textpos < (unsigned long) -4096)) {
Index: linux-2.6-2/fs/binfmt_som.c
===================================================================
--- linux-2.6-2.orig/fs/binfmt_som.c
+++ linux-2.6-2/fs/binfmt_som.c
@@ -148,10 +148,8 @@ static int map_som_binary(struct file *f
code_size = SOM_PAGEALIGN(hpuxhdr->exec_tsize);
current->mm->start_code = code_start;
current->mm->end_code = code_start + code_size;
- down_write(&current->mm->mmap_sem);
retval = do_mmap(file, code_start, code_size, prot,
flags, SOM_PAGESTART(hpuxhdr->exec_tfile));
- up_write(&current->mm->mmap_sem);
if (retval < 0 && retval > -1024)
goto out;

@@ -159,20 +157,16 @@ static int map_som_binary(struct file *f
data_size = SOM_PAGEALIGN(hpuxhdr->exec_dsize);
current->mm->start_data = data_start;
current->mm->end_data = bss_start = data_start + data_size;
- down_write(&current->mm->mmap_sem);
retval = do_mmap(file, data_start, data_size,
prot | PROT_WRITE, flags,
SOM_PAGESTART(hpuxhdr->exec_dfile));
- up_write(&current->mm->mmap_sem);
if (retval < 0 && retval > -1024)
goto out;

som_brk = bss_start + SOM_PAGEALIGN(hpuxhdr->exec_bsize);
current->mm->start_brk = current->mm->brk = som_brk;
- down_write(&current->mm->mmap_sem);
retval = do_mmap(NULL, bss_start, som_brk - bss_start,
prot | PROT_WRITE, MAP_FIXED | MAP_PRIVATE, 0);
- up_write(&current->mm->mmap_sem);
if (retval > 0 || retval < -1024)
retval = 0;
out:
Index: linux-2.6-2/fs/nfs/file.c
===================================================================
--- linux-2.6-2.orig/fs/nfs/file.c
+++ linux-2.6-2/fs/nfs/file.c
@@ -41,6 +41,9 @@
static int nfs_file_open(struct inode *, struct file *);
static int nfs_file_release(struct inode *, struct file *);
static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin);
+static int
+nfs_file_mmap_prepare(struct file * file, unsigned long addr, unsigned long len,
+ unsigned long prot, unsigned long flags, unsigned long pgoff);
static int nfs_file_mmap(struct file *, struct vm_area_struct *);
static ssize_t nfs_file_splice_read(struct file *filp, loff_t *ppos,
struct pipe_inode_info *pipe,
@@ -64,6 +67,7 @@ const struct file_operations nfs_file_op
.write = do_sync_write,
.aio_read = nfs_file_read,
.aio_write = nfs_file_write,
+ .mmap_prepare = nfs_file_mmap_prepare,
.mmap = nfs_file_mmap,
.open = nfs_file_open,
.flush = nfs_file_flush,
@@ -270,7 +274,8 @@ nfs_file_splice_read(struct file *filp,
}

static int
-nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
+nfs_file_mmap_prepare(struct file * file, unsigned long addr, unsigned long len,
+ unsigned long prot, unsigned long flags, unsigned long pgoff)
{
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = dentry->d_inode;
@@ -279,13 +284,17 @@ nfs_file_mmap(struct file * file, struct
dfprintk(VFS, "nfs: mmap(%s/%s)\n",
dentry->d_parent->d_name.name, dentry->d_name.name);

- status = nfs_revalidate_mapping(inode, file->f_mapping);
- if (!status) {
- vma->vm_ops = &nfs_file_vm_ops;
- vma->vm_flags |= VM_CAN_NONLINEAR;
- file_accessed(file);
- }
- return status;
+ return nfs_revalidate_mapping(inode, file->f_mapping);
+}
+
+static int
+nfs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ vma->vm_ops = &nfs_file_vm_ops;
+ vma->vm_flags |= VM_CAN_NONLINEAR;
+ file_accessed(file);
+
+ return 0;
}

/*
Index: linux-2.6-2/include/linux/fs.h
===================================================================
--- linux-2.6-2.orig/include/linux/fs.h
+++ linux-2.6-2/include/linux/fs.h
@@ -1172,6 +1172,7 @@ struct file_operations {
int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
+ int (*mmap_prepare) (struct file *, unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, unsigned long pgoff);
int (*mmap) (struct file *, struct vm_area_struct *);
int (*open) (struct inode *, struct file *);
int (*flush) (struct file *, fl_owner_t id);
Index: linux-2.6-2/include/linux/mm.h
===================================================================
--- linux-2.6-2.orig/include/linux/mm.h
+++ linux-2.6-2/include/linux/mm.h
@@ -980,6 +980,10 @@ extern int install_special_mapping(struc

extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);

+extern unsigned long do_mmap_pgoff_locked(
+ struct file *file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flag, unsigned long pgoff);
extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flag, unsigned long pgoff);
@@ -988,7 +992,7 @@ extern unsigned long mmap_region(struct
unsigned int vm_flags, unsigned long pgoff,
int accountable);

-static inline unsigned long do_mmap(struct file *file, unsigned long addr,
+static inline unsigned long do_mmap_locked(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flag, unsigned long offset)
{
@@ -996,11 +1000,16 @@ static inline unsigned long do_mmap(stru
if ((offset + PAGE_ALIGN(len)) < offset)
goto out;
if (!(offset & ~PAGE_MASK))
- ret = do_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
+ ret = do_mmap_pgoff_locked(file, addr, len, prot,
+ flag, offset >> PAGE_SHIFT);
out:
return ret;
}

+extern unsigned long do_mmap(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flag, unsigned long offset);
+
extern int do_munmap(struct mm_struct *, unsigned long, size_t);

extern unsigned long do_brk(unsigned long, unsigned long);
Index: linux-2.6-2/ipc/shm.c
===================================================================
--- linux-2.6-2.orig/ipc/shm.c
+++ linux-2.6-2/ipc/shm.c
@@ -1012,7 +1012,7 @@ long do_shmat(int shmid, char __user *sh
goto invalid;
}

- user_addr = do_mmap (file, addr, size, prot, flags, 0);
+ user_addr = do_mmap_locked (file, addr, size, prot, flags, 0);
*raddr = user_addr;
err = 0;
if (IS_ERR_VALUE(user_addr))
Index: linux-2.6-2/mm/mmap.c
===================================================================
--- linux-2.6-2.orig/mm/mmap.c
+++ linux-2.6-2/mm/mmap.c
@@ -888,9 +888,10 @@ void vm_stat_account(struct mm_struct *m
* The caller must hold down_write(current->mm->mmap_sem).
*/

-unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
- unsigned long len, unsigned long prot,
- unsigned long flags, unsigned long pgoff)
+static unsigned long __do_mmap_pgoff_locked(
+ struct file * file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flags, unsigned long pgoff)
{
struct mm_struct * mm = current->mm;
struct inode *inode;
@@ -1026,10 +1027,66 @@ unsigned long do_mmap_pgoff(struct file
return mmap_region(file, addr, len, flags, vm_flags, pgoff,
accountable);
}
+
+unsigned long do_mmap_pgoff_locked(struct file * file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flags, unsigned long pgoff)
+{
+ WARN_ON(file && file->f_op->mmap_prepare);
+ return __do_mmap_pgoff_locked(file, addr, len, prot, flags, pgoff);
+}
+EXPORT_SYMBOL(do_mmap_pgoff_locked);
+
+unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flags, unsigned long pgoff)
+{
+ struct mm_struct *mm = current->mm;
+ unsigned long ret;
+
+ if (file && file->f_op->mmap_prepare) {
+ ret = file->f_op->mmap_prepare(file, addr,
+ len, prot, flags, pgoff);
+ if (ret)
+ return ret;
+ }
+
+ down_write(&mm->mmap_sem);
+ ret = __do_mmap_pgoff_locked(file, addr, len, prot, flags, pgoff);
+ up_write(&mm->mmap_sem);
+
+ return ret;
+}
EXPORT_SYMBOL(do_mmap_pgoff);

+unsigned long do_mmap(struct file *file, unsigned long addr,
+ unsigned long len, unsigned long prot,
+ unsigned long flags, unsigned long offset)
+{
+ struct mm_struct *mm = current->mm;
+ unsigned long ret = -EINVAL;
+ unsigned long pgoff = offset >> PAGE_SHIFT;
+
+ if ((offset + PAGE_ALIGN(len)) < offset || (offset & ~PAGE_MASK))
+ return ret;
+
+ if (file && file->f_op->mmap_prepare) {
+ ret = file->f_op->mmap_prepare(file, addr,
+ len, prot, flags, pgoff);
+ if (ret)
+ return ret;
+ }
+
+ down_write(&mm->mmap_sem);
+ ret = __do_mmap_pgoff_locked(file, addr, len, prot, flags, pgoff);
+ up_write(&mm->mmap_sem);
+
+ return ret;
+}
+EXPORT_SYMBOL(do_mmap);
+
/*
- * Some shared mappigns will want the pages marked read-only
+ * Some shared mappings 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).


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