- trivial: cache file->f_dentry->d_inode; saves a few bytes of compiled
size.
- move expand_stack inside ARCH_STACK_GROWSUP, add an alternate
implementation for PA-RISC.
- partially fix the comment (mmap_sem is held for READ, not for WRITE).
It still doesn't make sense, saying we don't need to take the spinlock
right before we take it. I expect one of the vm hackers will know
what the right thing is.
diff -urpNX dontdiff linux-2.5.30/mm/mmap.c linux-2.5.30-willy/mm/mmap.c
--- linux-2.5.30/mm/mmap.c 2002-08-02 05:44:53.000000000 -0600
+++ linux-2.5.30-willy/mm/mmap.c 2002-08-02 08:24:26.000000000 -0600
@@ -422,6 +422,7 @@ unsigned long do_mmap_pgoff(struct file
{
struct mm_struct * mm = current->mm;
struct vm_area_struct * vma, * prev;
+ struct inode *inode = NULL;
unsigned int vm_flags;
int correct_wcount = 0;
int error;
@@ -469,17 +470,18 @@ unsigned long do_mmap_pgoff(struct file
}
if (file) {
+ inode = file->f_dentry->d_inode;
switch (flags & MAP_TYPE) {
case MAP_SHARED:
if ((prot & PROT_WRITE) && !(file->f_mode & FMODE_WRITE))
return -EACCES;
/* Make sure we don't allow writing to an append-only file.. */
- if (IS_APPEND(file->f_dentry->d_inode) && (file->f_mode & FMODE_WRITE))
+ if (IS_APPEND(inode) && (file->f_mode & FMODE_WRITE))
return -EACCES;
/* make sure there are no mandatory locks on the file. */
- if (locks_verify_locked(file->f_dentry->d_inode))
+ if (locks_verify_locked(inode))
return -EAGAIN;
vm_flags |= VM_SHARED | VM_MAYSHARE;
@@ -603,7 +605,7 @@ munmap_back:
vma_link(mm, vma, prev, rb_link, rb_parent);
if (correct_wcount)
- atomic_inc(&file->f_dentry->d_inode->i_writecount);
+ atomic_inc(&inode->i_writecount);
out:
mm->total_vm += len >> PAGE_SHIFT;
@@ -615,7 +617,7 @@ out:
unmap_and_free_vma:
if (correct_wcount)
- atomic_inc(&file->f_dentry->d_inode->i_writecount);
+ atomic_inc(&inode->i_writecount);
vma->vm_file = NULL;
fput(file);
@@ -755,38 +757,41 @@ struct vm_area_struct * find_vma_prev(st
return prev ? prev->vm_next : vma;
}
+#ifdef ARCH_STACK_GROWSUP
/*
- * vma is the first one with address < vma->vm_end,
- * and even address < vma->vm_start. Have to extend vma.
+ * vma is the first one with address > vma->vm_end. Have to extend vma.
*/
int expand_stack(struct vm_area_struct * vma, unsigned long address)
{
unsigned long grow;
+ if (!(vma->vm_flags & VM_GROWSUP))
+ return -EFAULT;
+
/*
* vma->vm_start/vm_end cannot change under us because the caller
- * is required to hold the mmap_sem in write mode. We need to get
+ * is required to hold the mmap_sem in read mode. We need to get
* the spinlock only before relocating the vma range ourself.
*/
+ address += 4 + PAGE_SIZE - 1;
address &= PAGE_MASK;
spin_lock(&vma->vm_mm->page_table_lock);
- grow = (vma->vm_start - address) >> PAGE_SHIFT;
+ grow = (address - vma->vm_end) >> PAGE_SHIFT;
/* Overcommit.. */
- if(!vm_enough_memory(grow)) {
+ if (!vm_enough_memory(grow)) {
spin_unlock(&vma->vm_mm->page_table_lock);
return -ENOMEM;
}
- if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur ||
+ if (address - vma->vm_start > current->rlim[RLIMIT_STACK].rlim_cur ||
((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) >
current->rlim[RLIMIT_AS].rlim_cur) {
spin_unlock(&vma->vm_mm->page_table_lock);
vm_unacct_memory(grow);
return -ENOMEM;
}
- vma->vm_start = address;
- vma->vm_pgoff -= grow;
+ vma->vm_end = address;
vma->vm_mm->total_vm += grow;
if (vma->vm_flags & VM_LOCKED)
vma->vm_mm->locked_vm += grow;
@@ -794,7 +799,6 @@ int expand_stack(struct vm_area_struct *
return 0;
}
-#ifdef ARCH_STACK_GROWSUP
struct vm_area_struct * find_extend_vma(struct mm_struct * mm, unsigned long addr)
{
struct vm_area_struct *vma, *prev;
@@ -811,6 +815,44 @@ struct vm_area_struct * find_extend_vma(
return prev;
}
#else
+/*
+ * vma is the first one with address < vma->vm_start. Have to extend vma.
+ */
+int expand_stack(struct vm_area_struct * vma, unsigned long address)
+{
+ unsigned long grow;
+
+ /*
+ * vma->vm_start/vm_end cannot change under us because the caller
+ * is required to hold the mmap_sem in read mode. We need to get
+ * the spinlock only before relocating the vma range ourself.
+ */
+ address &= PAGE_MASK;
+ spin_lock(&vma->vm_mm->page_table_lock);
+ grow = (vma->vm_start - address) >> PAGE_SHIFT;
+
+ /* Overcommit.. */
+ if (!vm_enough_memory(grow)) {
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return -ENOMEM;
+ }
+
+ if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur ||
+ ((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) >
+ current->rlim[RLIMIT_AS].rlim_cur) {
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ vm_unacct_memory(grow);
+ return -ENOMEM;
+ }
+ vma->vm_start = address;
+ vma->vm_pgoff -= grow;
+ vma->vm_mm->total_vm += grow;
+ if (vma->vm_flags & VM_LOCKED)
+ vma->vm_mm->locked_vm += grow;
+ spin_unlock(&vma->vm_mm->page_table_lock);
+ return 0;
+}
+
struct vm_area_struct * find_extend_vma(struct mm_struct * mm, unsigned long addr)
{
struct vm_area_struct * vma;
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This archive was generated by hypermail 2b29 : Wed Aug 07 2002 - 22:00:19 EST