[PATCH 3/4] fsfreeze: manage kill signal when sb_start_pagefaultis called

From: Marco Stornelli
Date: Sat Apr 06 2013 - 06:13:13 EST


In every place where sb_start_pagefault was called now we must manage
the error code and return VM_FAULT_RETRY.

Signed-off-by: Marco Stornelli <marco.stornelli@xxxxxxxxx>
---
fs/btrfs/inode.c | 4 +++-
fs/buffer.c | 4 +++-
fs/ext4/inode.c | 4 +++-
fs/f2fs/file.c | 4 +++-
fs/gfs2/file.c | 4 +++-
fs/nilfs2/file.c | 4 +++-
fs/ocfs2/mmap.c | 4 +++-
include/linux/fs.h | 6 ++++--
mm/filemap.c | 7 +++++--
9 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 09c58a3..a6166f4 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7559,7 +7559,9 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
u64 page_start;
u64 page_end;

- sb_start_pagefault(inode->i_sb);
+ ret = sb_start_pagefault(inode->i_sb);
+ if (ret)
+ return VM_FAULT_RETRY;
ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
if (!ret) {
ret = file_update_time(vma->vm_file);
diff --git a/fs/buffer.c b/fs/buffer.c
index b4dcb34..6d3d2cc 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2383,7 +2383,9 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
int ret;
struct super_block *sb = file_inode(vma->vm_file)->i_sb;

- sb_start_pagefault(sb);
+ ret = sb_start_pagefault(sb);
+ if (ret)
+ return VM_FAULT_RETRY;

/*
* Update file times before taking page lock. We may end up failing the
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b3a5213..efc47f6 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5023,7 +5023,9 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
get_block_t *get_block;
int retries = 0;

- sb_start_pagefault(inode->i_sb);
+ ret = sb_start_pagefault(inode->i_sb);
+ if (ret)
+ return VM_FAULT_RETRY;
file_update_time(vma->vm_file);
/* Delalloc case is easy... */
if (test_opt(inode->i_sb, DELALLOC) &&
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 958a46d..cce4147 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -37,7 +37,9 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,

f2fs_balance_fs(sbi);

- sb_start_pagefault(inode->i_sb);
+ err = sb_start_pagefault(inode->i_sb);
+ if (err)
+ return VM_FAULT_RETRY;

mutex_lock_op(sbi, DATA_NEW);

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index d79c2da..071e777 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -396,7 +396,9 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
loff_t size;
int ret;

- sb_start_pagefault(inode->i_sb);
+ ret = sb_start_pagefault(inode->i_sb);
+ if (ret)
+ return VM_FAULT_RETRY;

/* Update file times before taking page lock */
file_update_time(vma->vm_file);
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 08fdb77..1c7678a 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -74,7 +74,9 @@ static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
return VM_FAULT_SIGBUS; /* -ENOSPC */

- sb_start_pagefault(inode->i_sb);
+ ret = sb_start_pagefault(inode->i_sb);
+ if (ret)
+ return VM_FAULT_RETRY;
lock_page(page);
if (page->mapping != inode->i_mapping ||
page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
index 10d66c7..f0973ae 100644
--- a/fs/ocfs2/mmap.c
+++ b/fs/ocfs2/mmap.c
@@ -136,7 +136,9 @@ static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
sigset_t oldset;
int ret;

- sb_start_pagefault(inode->i_sb);
+ ret = sb_start_pagefault(inode->i_sb);
+ if (ret)
+ return VM_FAULT_RETRY;
ocfs2_block_signals(&oldset);

/*
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 03921d6..550574e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1407,6 +1407,8 @@ static inline int sb_start_write_trylock(struct super_block *sb)
* sb_start_pagefault - get write access to a superblock from a page fault
* @sb: the super we write to
*
+ * It returns zero when no error occured, the error code otherwise.
+ *
* When a process starts handling write page fault, it should embed the
* operation into sb_start_pagefault() - sb_end_pagefault() pair to get
* exclusion against file system freezing. This is needed since the page fault
@@ -1422,9 +1424,9 @@ static inline int sb_start_write_trylock(struct super_block *sb)
* mmap_sem
* -> sb_start_pagefault
*/
-static inline void sb_start_pagefault(struct super_block *sb)
+static inline int sb_start_pagefault(struct super_block *sb)
{
- __sb_start_write_wait(sb, SB_FREEZE_PAGEFAULT, false);
+ __sb_start_write_wait(sb, SB_FREEZE_PAGEFAULT, true);
}

/*
diff --git a/mm/filemap.c b/mm/filemap.c
index b238671..acf8d97 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1712,9 +1712,11 @@ int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = file_inode(vma->vm_file);
- int ret = VM_FAULT_LOCKED;
+ int ret = 0;

- sb_start_pagefault(inode->i_sb);
+ ret = sb_start_pagefault(inode->i_sb);
+ if (ret)
+ return VM_FAULT_RETRY;
file_update_time(vma->vm_file);
lock_page(page);
if (page->mapping != inode->i_mapping) {
@@ -1727,6 +1729,7 @@ int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
* progress, we are guaranteed that writeback during freezing will
* see the dirty page and writeprotect it again.
*/
+ ret = VM_FAULT_LOCKED;
set_page_dirty(page);
wait_for_stable_page(page);
out:
--
1.7.3.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/