Re: [f2fs-dev] [PATCH 2/2] f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE
From: Chao Yu
Date: Thu Nov 26 2020 - 01:54:21 EST
Daeho,
On 2020/11/26 14:35, Daeho Jeong wrote:
Chao,
A little bit wired, why not failing cluster_may_compress() for user mode, and
let writepages write cluster as raw blocks, in-where we can update i_compr_blocks
and global compr block stats correctly.
For decompression ioctl, I've made f2fs_need_compress_data() return
"false" to prevent compression write, so we don't use
f2fs_write_compressed_pages() anymore in this case.
Because of this, I manually updated i_compr_blocks. Do you have any
suggestions on this?
I meant, we can control condition to call into below stack, then i_compr_blocks
can be updated correctly.
- f2fs_ioc_decompress_file
- writepages
- f2fs_write_multi_pages
- cluster_may_compress return false when ioc_decompress is in-process.
- f2fs_write_raw_pages
- f2fs_do_write_data_page
- f2fs_i_compr_blocks_update
Thanks,
2020년 11월 26일 (목) 오후 2:04, Daeho Jeong <daeho43@xxxxxxxxx>님이 작성:
Eric,
do_page_cache_ra() is defined in mm/internal.h for internal use
between in mm, so we cannot use this one right now.
So, I think we could use page_cache_ra_unbounded(), because we already
check i_size boundary on our own.
What do you think?
2020년 11월 24일 (화) 오후 12:05, Chao Yu <yuchao0@xxxxxxxxxx>님이 작성:
On 2020/11/23 11:17, Daeho Jeong wrote:
From: Daeho Jeong <daehojeong@xxxxxxxxxx>
Added two ioctl to decompress/compress explicitly the compression
enabled file in "compress_mode=user-based" mount option.
Using these two ioctls, the users can make a control of compression
and decompression of their files.
Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
---
fs/f2fs/file.c | 181 +++++++++++++++++++++++++++++++++++++-
include/uapi/linux/f2fs.h | 2 +
2 files changed, 182 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index be8db06aca27..e8f142470e87 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4026,6 +4026,180 @@ static int f2fs_ioc_set_compress_option(struct file *filp, unsigned long arg)
return ret;
}
+static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len)
+{
+ DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, page_idx);
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ struct address_space *mapping = inode->i_mapping;
+ struct page *page;
+ pgoff_t redirty_idx = page_idx;
+ int i, page_len = 0, ret = 0;
+
+ page_cache_ra_unbounded(&ractl, len, 0);
+
+ for (i = 0; i < len; i++, page_idx++) {
+ page = read_cache_page(mapping, page_idx, NULL, NULL);
+ if (IS_ERR(page)) {
+ ret = PTR_ERR(page);
+ f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
+ "couldn't be read (errno:%d).\n",
+ __func__, inode->i_ino, page_idx, ret);
This is a common error case during calling read_cache_page(), IMO, this looks
more like a debug log, so I prefer to print nothing here, or at least using
f2fs_debug() instead.
+ break;
+ }
+ page_len++;
+ }
+
+ for (i = 0; i < page_len; i++, redirty_idx++) {
+ page = find_lock_page(mapping, redirty_idx);
+ if (!page) {
+ ret = -ENOENT;
+ f2fs_warn(sbi, "%s: inode (%lu) : page_index (%lu) "
+ "couldn't be found (errno:%d).\n",
+ __func__, inode->i_ino, redirty_idx, ret);
Ditto.
+ }
+ set_page_dirty(page);
+ f2fs_put_page(page, 1);
+ f2fs_put_page(page, 0);
+ }
+
+ return ret;
+}
+
+static int f2fs_ioc_decompress_file(struct file *filp, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ struct f2fs_inode_info *fi = F2FS_I(inode);
+ pgoff_t page_idx = 0, last_idx;
+ int cluster_size = F2FS_I(inode)->i_cluster_size;
+ int count, ret;
+
+ if (!f2fs_sb_has_compression(sbi))
+ return -EOPNOTSUPP;
+
+ if (!(filp->f_mode & FMODE_WRITE))
+ return -EBADF;
+
+ if (!f2fs_compressed_file(inode))
+ return -EINVAL;
Before compressubg/decompressing file, should we check whether current inode's
compress algorithm backend is available in f2fs module?
+
+ f2fs_balance_fs(F2FS_I_SB(inode), true);
+
+ file_start_write(filp);
+ inode_lock(inode);
+
+ if (f2fs_is_mmap_file(inode)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
+ if (ret)
+ goto out;
+
+ if (!atomic_read(&fi->i_compr_blocks))
+ goto out;
+
+ last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+
+ count = last_idx - page_idx;
+ while (count) {
+ int len = min(cluster_size, count);
+
+ ret = redirty_blocks(inode, page_idx, len);
+
unneeded blank line..
+ if (ret < 0)
+ break;
+
+ page_idx += len;
+ count -= len;
Considering there isn't so many memory in low-end device, how about calling
filemap_fdatawrite() to writeback cluster after redirty several clusters
or xxMB?
+ }
+
+ if (!ret)
+ ret = filemap_write_and_wait_range(inode->i_mapping, 0,
+ LLONG_MAX);
+
+ if (!ret) {
+ stat_sub_compr_blocks(inode, atomic_read(&fi->i_compr_blocks));
+ atomic_set(&fi->i_compr_blocks, 0);
+ f2fs_mark_inode_dirty_sync(inode, true);
A little bit wired, why not failing cluster_may_compress() for user mode, and
let writepages write cluster as raw blocks, in-where we can update i_compr_blocks
and global compr block stats correctly.
+ } else {
+ f2fs_warn(sbi, "%s: The file might be partially decompressed "
+ "(errno=%d). Please delete the file.\n",
+ __func__, ret);
+ }
+out:
+ inode_unlock(inode);
+ file_end_write(filp);
+
+ return ret;
+}
+
+static int f2fs_ioc_compress_file(struct file *filp, unsigned long arg)
+{
+ struct inode *inode = file_inode(filp);
+ struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+ pgoff_t page_idx = 0, last_idx;
+ int cluster_size = F2FS_I(inode)->i_cluster_size;
+ int count, ret;
+
+ if (!f2fs_sb_has_compression(sbi))
+ return -EOPNOTSUPP;
+
+ if (!(filp->f_mode & FMODE_WRITE))
+ return -EBADF;
+
+ if (!f2fs_compressed_file(inode))
+ return -EINVAL;
algorithm backend check?
+
+ f2fs_balance_fs(F2FS_I_SB(inode), true);
+
+ file_start_write(filp);
+ inode_lock(inode);
+
+ if (f2fs_is_mmap_file(inode)) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
+ if (ret)
+ goto out;
+
+ set_inode_flag(inode, FI_ENABLE_COMPRESS);
+
+ last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
+
+ count = last_idx - page_idx;
+ while (count) {
+ int len = min(cluster_size, count);
+
+ ret = redirty_blocks(inode, page_idx, len);
+
Ditto.
Thanks,
+ if (ret < 0)
+ break;
+
+ page_idx += len;
+ count -= len;
+ }
+
+ if (!ret)
+ ret = filemap_write_and_wait_range(inode->i_mapping, 0,
+ LLONG_MAX);
+
+ clear_inode_flag(inode, FI_ENABLE_COMPRESS);
+
+ if (ret)
+ f2fs_warn(sbi, "%s: The file might be partially compressed "
+ "(errno=%d). Please delete the file.\n",
+ __func__, ret);
+out:
+ inode_unlock(inode);
+ file_end_write(filp);
+
+ return ret;
+}
+
static long __f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
@@ -4113,6 +4287,10 @@ static long __f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return f2fs_ioc_get_compress_option(filp, arg);
case F2FS_IOC_SET_COMPRESS_OPTION:
return f2fs_ioc_set_compress_option(filp, arg);
+ case F2FS_IOC_DECOMPRESS_FILE:
+ return f2fs_ioc_decompress_file(filp, arg);
+ case F2FS_IOC_COMPRESS_FILE:
+ return f2fs_ioc_compress_file(filp, arg);
default:
return -ENOTTY;
}
@@ -4352,7 +4530,8 @@ long f2fs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case F2FS_IOC_SEC_TRIM_FILE:
case F2FS_IOC_GET_COMPRESS_OPTION:
case F2FS_IOC_SET_COMPRESS_OPTION:
- break;
+ case F2FS_IOC_DECOMPRESS_FILE:
+ case F2FS_IOC_COMPRESS_FILE:
default:
return -ENOIOCTLCMD;
}
diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h
index f00199a2e38b..352a822d4370 100644
--- a/include/uapi/linux/f2fs.h
+++ b/include/uapi/linux/f2fs.h
@@ -40,6 +40,8 @@
struct f2fs_comp_option)
#define F2FS_IOC_SET_COMPRESS_OPTION _IOW(F2FS_IOCTL_MAGIC, 22, \
struct f2fs_comp_option)
+#define F2FS_IOC_DECOMPRESS_FILE _IO(F2FS_IOCTL_MAGIC, 23)
+#define F2FS_IOC_COMPRESS_FILE _IO(F2FS_IOCTL_MAGIC, 24)
/*
* should be same as XFS_IOC_GOINGDOWN.
.