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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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47
fs/adfs/dir_fplus.c
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@@ -112,34 +112,6 @@ adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
return ret;
}
static void
dir_memcpy(struct adfs_dir *dir, unsigned int offset, void *to, int len)
{
struct super_block *sb = dir->sb;
unsigned int buffer, partial, remainder;
buffer = offset >> sb->s_blocksize_bits;
offset &= sb->s_blocksize - 1;
partial = sb->s_blocksize - offset;
if (partial >= len)
memcpy(to, dir->bhs[buffer]->b_data + offset, len);
else {
char *c = (char *)to;
remainder = len - partial;
memcpy(c,
dir->bhs[buffer]->b_data + offset,
partial);
memcpy(c + partial,
dir->bhs[buffer + 1]->b_data,
remainder);
}
}
static int
adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
{
@@ -147,16 +119,19 @@ adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
(struct adfs_bigdirheader *) dir->bhs[0]->b_data;
struct adfs_bigdirentry bde;
unsigned int offset;
int ret = -ENOENT;
int ret;
if (dir->pos >= le32_to_cpu(h->bigdirentries))
goto out;
return -ENOENT;
offset = offsetof(struct adfs_bigdirheader, bigdirname);
offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
offset += dir->pos * sizeof(struct adfs_bigdirentry);
dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));
ret = adfs_dir_copyfrom(&bde, dir, offset,
sizeof(struct adfs_bigdirentry));
if (ret)
return ret;
obj->loadaddr = le32_to_cpu(bde.bigdirload);
obj->execaddr = le32_to_cpu(bde.bigdirexec);
@@ -170,13 +145,15 @@ adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
offset += le32_to_cpu(h->bigdirentries) * sizeof(struct adfs_bigdirentry);
offset += le32_to_cpu(bde.bigdirobnameptr);
dir_memcpy(dir, offset, obj->name, obj->name_len);
ret = adfs_dir_copyfrom(obj->name, dir, offset, obj->name_len);
if (ret)
return ret;
adfs_object_fixup(dir, obj);
dir->pos += 1;
ret = 0;
out:
return ret;
return 0;
}
const struct adfs_dir_ops adfs_fplus_dir_ops = {