xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ext4: Use page_mkwrite vma_operations to get mmap write notification.

Browse Source 
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. The changes are also needed to handle ENOSPC
when writing to an mmap section of files with holes.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Aneesh Kumar K.V
2008-07-11 19:27:31 -04:00
committed by Theodore Ts'o
parent 93e3270c87
commit 2e9ee85035
3 changed files with 80 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
fs/ext4/file.c
View File

@@ -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,