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fs/adfs: dir: add generic copy functions

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Directories can span multiple buffers, and we currently open-code
memcpy access to these buffers, including dealing with entries that
are split across multiple buffers.  Such code exists in both
directory format implementations.

Provide common functions to allow data to be copied from/to the
directory buffers as if they were a contiguous set of buffers, and
use them when accessing directories.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Russell King
2019-12-09 11:09:30 +00:00
committed by Al Viro
parent acf5f0be8a
commit a317120bf7
4 changed files with 75 additions and 82 deletions
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56
fs/adfs/dir_f.c
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@@ -224,24 +224,12 @@ adfs_obj2dir(struct adfs_direntry *de, struct object_info *obj)
static int
__adfs_dir_get(struct adfs_dir *dir, int pos, struct object_info *obj)
{
struct super_block *sb = dir->sb;
struct adfs_direntry de;
int thissize, buffer, offset;
int ret;
buffer = pos >> sb->s_blocksize_bits;
if (buffer > dir->nr_buffers)
return -EINVAL;
offset = pos & (sb->s_blocksize - 1);
thissize = sb->s_blocksize - offset;
if (thissize > 26)
thissize = 26;
memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
if (thissize != 26)
memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
26 - thissize);
ret = adfs_dir_copyfrom(&de, dir, pos, 26);
if (ret)
return ret;
if (!de.dirobname[0])
return -ENOENT;
@@ -254,42 +242,16 @@ __adfs_dir_get(struct adfs_dir *dir, int pos, struct object_info *obj)
static int
__adfs_dir_put(struct adfs_dir *dir, int pos, struct object_info *obj)
{
struct super_block *sb = dir->sb;
struct adfs_direntry de;
int thissize, buffer, offset;
int ret;
buffer = pos >> sb->s_blocksize_bits;
ret = adfs_dir_copyfrom(&de, dir, pos, 26);
if (ret)
return ret;
if (buffer > dir->nr_buffers)
return -EINVAL;
offset = pos & (sb->s_blocksize - 1);
thissize = sb->s_blocksize - offset;
if (thissize > 26)
thissize = 26;
/*
* Get the entry in total
*/
memcpy(&de, dir->bh[buffer]->b_data + offset, thissize);
if (thissize != 26)
memcpy(((char *)&de) + thissize, dir->bh[buffer + 1]->b_data,
26 - thissize);
/*
* update it
*/
adfs_obj2dir(&de, obj);
/*
* Put the new entry back
*/
memcpy(dir->bh[buffer]->b_data + offset, &de, thissize);
if (thissize != 26)
memcpy(dir->bh[buffer + 1]->b_data, ((char *)&de) + thissize,
26 - thissize);
return 0;
return adfs_dir_copyto(dir, pos, &de, 26);
}
/*