2008-02-18 11:53:56

by Aneesh Kumar K.V

Subject: [PATCH] ext4: Use page_mkwrite vma_operations to get mmap write notification.

We would like to get notified when we are doing a write on mmap section.
This is needed with respect to preallocated area. We split the preallocated
area into initialzed extent and uninitialzed extent in the call back. This
let us handle ENOSPC better. Otherwise we get ENOSPC in the writepage and
that would result in data loss.

Signed-off-by: Aneesh Kumar K.V <[email protected]>
---
fs/ext4/file.c | 19 ++++++++++++++++++-
fs/ext4/inode.c | 6 ++++++
include/linux/ext4_fs.h | 1 +
3 files changed, 25 insertions(+), 1 deletions(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 20507a2..77341c1 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -123,6 +123,23 @@ force_commit:
return ret;
}

+static struct vm_operations_struct ext4_file_vm_ops = {
+ .fault = filemap_fault,
+ .page_mkwrite = ext4_page_mkwrite,
+};
+
+static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct address_space *mapping = file->f_mapping;
+
+ if (!mapping->a_ops->readpage)
+ return -ENOEXEC;
+ file_accessed(file);
+ vma->vm_ops = &ext4_file_vm_ops;
+ vma->vm_flags |= VM_CAN_NONLINEAR;
+ return 0;
+}
+
const struct file_operations ext4_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
@@ -133,7 +150,7 @@ const struct file_operations ext4_file_operations = {
#ifdef CONFIG_COMPAT
.compat_ioctl = ext4_compat_ioctl,
#endif
- .mmap = generic_file_mmap,
+ .mmap = ext4_file_mmap,
.open = generic_file_open,
.release = ext4_release_file,
.fsync = ext4_sync_file,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 34f3eb6..81faa67 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3466,3 +3466,9 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)

return err;
}
+
+int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+{
+ return block_page_mkwrite(vma, page, ext4_get_block);
+}
+
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index 22810b1..8f5a563 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -1059,6 +1059,7 @@ extern void ext4_set_aops(struct inode *inode);
extern int ext4_writepage_trans_blocks(struct inode *);
extern int ext4_block_truncate_page(handle_t *handle, struct page *page,
struct address_space *mapping, loff_t from);
+extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page);

/* ioctl.c */
extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
--
1.5.4.1.97.g40aab-dirty

2008-02-18 11:54:01

by Aneesh Kumar K.V

Subject: [PATCH] ext4: Don't mark the filesystem with errors if we fail to fallocate.

IF we fail fallocate don't call ext4_error. Also don't hide errors
from ext4_get_blocks_wrap

Signed-off-by: Aneesh Kumar K.V <[email protected]>
---
fs/ext4/extents.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 5b22f71..bb01ac6 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2653,13 +2653,14 @@ retry:
ret = ext4_get_blocks_wrap(handle, inode, block,
max_blocks, &map_bh,
EXT4_CREATE_UNINITIALIZED_EXT, 0);
- WARN_ON(ret <= 0);
if (ret <= 0) {
+#ifdef EXT4FS_DEBUG
+ WARN_ON(ret <= 0);
ext4_error(inode->i_sb, "ext4_fallocate",
"ext4_ext_get_blocks returned error: "
"inode#%lu, block=%u, max_blocks=%lu",
inode->i_ino, block, max_blocks);
- ret = -EIO;
+#endif
ext4_mark_inode_dirty(handle, inode);
ret2 = ext4_journal_stop(handle);
break;
--
1.5.4.1.97.g40aab-dirty