[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH 1/4] libpager: pager_write_page () should not unmap page
From: |
Sergey Bugaev |
Subject: |
[PATCH 1/4] libpager: pager_write_page () should not unmap page |
Date: |
Sat, 8 May 2021 18:31:41 +0300 |
Clarify this in the documentation, and fix the storeio implementation.
---
doc/hurd.texi | 6 +++---
libpager/pager.h | 6 +++---
storeio/pager.c | 8 +++-----
tmpfs/pager-stubs.c | 6 +++---
4 files changed, 12 insertions(+), 14 deletions(-)
diff --git a/doc/hurd.texi b/doc/hurd.texi
index c8db86b5..239d82da 100644
--- a/doc/hurd.texi
+++ b/doc/hurd.texi
@@ -1536,9 +1536,9 @@ only permissible error returns are @code{EIO},
@code{EDQUOT}, and
@deftypefun error_t pager_write_page (@w{struct user_pager_info *@var{pager}},
@w{vm_offset_t @var{page}}, @w{vm_address_t @var{buf}})
For pager @var{pager}, synchronously write one page from @var{buf} to
-offset @var{page}. In addition, @code{vm_deallocate} (or equivalent)
-@var{buf}. The only permissible error returns are @code{EIO},
-@code{EDQUOT}, and @code{ENOSPC}.
+offset @var{page}. Do not deallocate @var{buf}, and do not keep any
+references to @var{buf}. The only permissible error returns are
+@code{EIO}, @code{EDQUOT}, and @code{ENOSPC}.
@end deftypefun
@deftypefun error_t pager_unlock_page (@w{struct user_pager_info
*@var{pager}}, @w{vm_offset_t @var{address}})
diff --git a/libpager/pager.h b/libpager/pager.h
index df7fbfc8..5c03b748 100644
--- a/libpager/pager.h
+++ b/libpager/pager.h
@@ -191,9 +191,9 @@ pager_read_page (struct user_pager_info *pager,
int *write_lock);
/* The user must define this function. For pager PAGER, synchronously
- write one page from BUF to offset PAGE. In addition, mfree
- (or equivalent) BUF. The only permissible error returns are EIO,
- EDQUOT, and ENOSPC. */
+ write one page from BUF to offset PAGE. Do not deallocate BUF, and do
+ not keep any references to BUF. The only permissible error returns
+ are EIO, EDQUOT, and ENOSPC. */
error_t
pager_write_page (struct user_pager_info *pager,
vm_offset_t page,
diff --git a/storeio/pager.c b/storeio/pager.c
index 12387939..01a1525c 100644
--- a/storeio/pager.c
+++ b/storeio/pager.c
@@ -66,9 +66,9 @@ pager_read_page (struct user_pager_info *upi,
return 0;
}
-/* For pager PAGER, synchronously write one page from BUF to offset PAGE. In
- addition, vm_deallocate (or equivalent) BUF. The only permissible error
- returns are EIO, EDQUOT, and ENOSPC. */
+/* For pager PAGER, synchronously write one page from BUF to offset PAGE.
+ Do not deallocate BUF, and do not keep any references to BUF. The only
+ permissible error returns are EIO, EDQUOT, and ENOSPC. */
error_t
pager_write_page (struct user_pager_info *upi,
vm_offset_t page, vm_address_t buf)
@@ -90,8 +90,6 @@ pager_write_page (struct user_pager_info *upi,
err = dev_write (dev, page, (char *)buf, want, &written);
- munmap ((caddr_t) buf, vm_page_size);
-
if (err || written < want)
return EIO;
else
diff --git a/tmpfs/pager-stubs.c b/tmpfs/pager-stubs.c
index 3299e218..883a635e 100644
--- a/tmpfs/pager-stubs.c
+++ b/tmpfs/pager-stubs.c
@@ -36,9 +36,9 @@ pager_read_page (struct user_pager_info *pager,
}
/* The user must define this function. For pager PAGER, synchronously
- write one page from BUF to offset PAGE. In addition, mfree
- (or equivalent) BUF. The only permissible error returns are EIO,
- EDQUOT, and ENOSPC. */
+ write one page from BUF to offset PAGE. Do not deallocate BUF, and do
+ not keep any references to BUF. The only permissible error returns
+ are EIO, EDQUOT, and ENOSPC. */
error_t
pager_write_page (struct user_pager_info *pager,
vm_offset_t page,
--
2.31.1
- [PATCH 3/6] libpager: Add error handling to various functions, (continued)
- [PATCH 3/6] libpager: Add error handling to various functions, Sergey Bugaev, 2021/05/06
- [PATCH 5/6] libpager: Fix overallocating pagemap, Sergey Bugaev, 2021/05/06
- And another patch..., Sergey Bugaev, 2021/05/06
- Re: And another patch..., Samuel Thibault, 2021/05/08
- Re: And another patch..., Sergey Bugaev, 2021/05/08
- [PATCH 0/4] _pager_do_write_request fixes, Sergey Bugaev, 2021/05/08
- [PATCH 3/4] libpager: Track which pages are precious, Sergey Bugaev, 2021/05/08
- [PATCH 4/4] libpager: Do not throw away precious pages, Sergey Bugaev, 2021/05/08
- [PATCH 2/4] libpager: Store omit_data in an array, Sergey Bugaev, 2021/05/08
- [PATCH 1/4] libpager: pager_write_page () should not unmap page,
Sergey Bugaev <=
- Re: [PATCH 1/4] libpager: pager_write_page () should not unmap page, Samuel Thibault, 2021/05/08
- Re: [PATCH 0/4] _pager_do_write_request fixes, Samuel Thibault, 2021/05/08