[PATCH 03/39] vfs: dedupe: extract helper for a single dedup

From: Miklos Szeredi
Date: Tue May 29 2018 - 11:17:10 EST


Extract vfs_dedupe_file_range_one() helper to deal with a single dedup
request.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/read_write.c | 89 +++++++++++++++++++++++++++++++--------------------------
1 file changed, 49 insertions(+), 40 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 1818581cadf6..82a53c44c0aa 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1964,6 +1964,44 @@ int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
}
EXPORT_SYMBOL(vfs_dedupe_file_range_compare);

+static s64 vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
+ struct file *dst_file, loff_t dst_pos,
+ u64 len)
+{
+ s64 ret;
+
+ ret = mnt_want_write_file(dst_file);
+ if (ret)
+ return ret;
+
+ ret = clone_verify_area(dst_file, dst_pos, len, true);
+ if (ret < 0)
+ goto out_drop_write;
+
+ ret = -EINVAL;
+ if (!(capable(CAP_SYS_ADMIN) || (dst_file->f_mode & FMODE_WRITE)))
+ goto out_drop_write;
+
+ ret = -EXDEV;
+ if (src_file->f_path.mnt != dst_file->f_path.mnt)
+ goto out_drop_write;
+
+ ret = -EISDIR;
+ if (S_ISDIR(file_inode(dst_file)->i_mode))
+ goto out_drop_write;
+
+ ret = -EINVAL;
+ if (!dst_file->f_op->dedupe_file_range)
+ goto out_drop_write;
+
+ ret = dst_file->f_op->dedupe_file_range(src_file, src_pos,
+ dst_file, dst_pos, len);
+out_drop_write:
+ mnt_drop_write_file(dst_file);
+
+ return ret;
+}
+
int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
{
struct file_dedupe_range_info *info;
@@ -1972,10 +2010,7 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
u64 len;
int i;
int ret;
- bool is_admin = capable(CAP_SYS_ADMIN);
u16 count = same->dest_count;
- struct file *dst_file;
- loff_t dst_off;
loff_t deduped;

if (!(file->f_mode & FMODE_READ))
@@ -2010,54 +2045,28 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
}

for (i = 0, info = same->info; i < count; i++, info++) {
- struct inode *dst;
struct fd dst_fd = fdget(info->dest_fd);
+ struct file *dst_file = dst_fd.file;

- dst_file = dst_fd.file;
if (!dst_file) {
info->status = -EBADF;
goto next_loop;
}
- dst = file_inode(dst_file);
-
- ret = mnt_want_write_file(dst_file);
- if (ret) {
- info->status = ret;
- goto next_loop;
- }
-
- dst_off = info->dest_offset;
- ret = clone_verify_area(dst_file, dst_off, len, true);
- if (ret < 0) {
- info->status = ret;
- goto next_file;
- }
- ret = 0;

if (info->reserved) {
info->status = -EINVAL;
- } else if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) {
- info->status = -EINVAL;
- } else if (file->f_path.mnt != dst_file->f_path.mnt) {
- info->status = -EXDEV;
- } else if (S_ISDIR(dst->i_mode)) {
- info->status = -EISDIR;
- } else if (dst_file->f_op->dedupe_file_range == NULL) {
- info->status = -EINVAL;
- } else {
- deduped = dst_file->f_op->dedupe_file_range(file, off,
- dst_file,
- info->dest_offset, len);
- if (deduped == -EBADE)
- info->status = FILE_DEDUPE_RANGE_DIFFERS;
- else if (deduped < 0)
- info->status = deduped;
- else
- info->bytes_deduped += deduped;
+ goto next_loop;
}

-next_file:
- mnt_drop_write_file(dst_file);
+ deduped = vfs_dedupe_file_range_one(file, off, dst_file,
+ info->dest_offset, len);
+ if (deduped == -EBADE)
+ info->status = FILE_DEDUPE_RANGE_DIFFERS;
+ else if (deduped < 0)
+ info->status = deduped;
+ else
+ info->bytes_deduped += deduped;
+
next_loop:
fdput(dst_fd);

--
2.14.3