/**
* vxfs_find_entry - find a mathing directory entry for a dentry
* @ip: directory inode
* @dp: dentry for which we want to find a direct
* @ppp: gets filled with the page the return value sits in
*
* Description:
* vxfs_find_entry finds a &struct vxfs_direct for the VFS directory
* cache entry @dp. @ppp will be filled with the page the return
* value resides in.
*
* Returns:
* The wanted direct on success, else a NULL pointer.
*/
static struct vxfs_direct *
vxfs_find_entry(struct inode *ip, struct dentry *dp, struct page **ppp)
{
u_long bsize = ip->i_sb->s_blocksize;
const char *name = dp->d_name.name;
int namelen = dp->d_name.len;
loff_t limit = VXFS_DIRROUND(ip->i_size);
struct vxfs_direct *de_exit = NULL;
loff_t pos = 0;
struct vxfs_sb_info *sbi = VXFS_SBI(ip->i_sb);
while (pos < limit) {
struct page *pp;
char *kaddr;
int pg_ofs = pos & ~PAGE_MASK;
pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
if (IS_ERR(pp))
return NULL;
kaddr = (char *)page_address(pp);
while (pg_ofs < PAGE_SIZE && pos < limit) {
struct vxfs_direct *de;
if ((pos & (bsize - 1)) < 4) {
struct vxfs_dirblk *dbp =
(struct vxfs_dirblk *)
(kaddr + (pos & ~PAGE_MASK));
int overhead = VXFS_DIRBLKOV(sbi, dbp);
pos += overhead;
pg_ofs += overhead;
}
de = (struct vxfs_direct *)(kaddr + pg_ofs);
if (!de->d_reclen) {
pos += bsize - 1;
pos &= ~(bsize - 1);
break;
}
pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
pos += fs16_to_cpu(sbi, de->d_reclen);
if (!de->d_ino)
continue;
if (namelen != fs16_to_cpu(sbi, de->d_namelen))
continue;
if (!memcmp(name, de->d_name, namelen)) {
*ppp = pp;
de_exit = de;
break;
}
}
if (!de_exit)
vxfs_put_page(pp);
else
break;
}
return de_exit;
}
/**
* vxfs_readdir - read a directory
* @fp: the directory to read
* @retp: return buffer
* @filler: filldir callback
*
* Description:
* vxfs_readdir fills @retp with directory entries from @fp
* using the VFS supplied callback @filler.
*
* Returns:
* Zero.
*/
static int
vxfs_readdir(struct file *fp, void *retp, filldir_t filler)
{
struct inode *ip = fp->f_path.dentry->d_inode;
struct super_block *sbp = ip->i_sb;
u_long bsize = sbp->s_blocksize;
u_long page, npages, block, pblocks, nblocks, offset;
loff_t pos;
switch ((long)fp->f_pos) {
case 0:
if (filler(retp, ".", 1, fp->f_pos, ip->i_ino, DT_DIR) < 0)
goto out;
fp->f_pos++;
/* fallthrough */
case 1:
if (filler(retp, "..", 2, fp->f_pos, VXFS_INO(ip)->vii_dotdot, DT_DIR) < 0)
goto out;
fp->f_pos++;
/* fallthrough */
}
pos = fp->f_pos - 2;
if (pos > VXFS_DIRROUND(ip->i_size))
return 0;
npages = dir_pages(ip);
nblocks = dir_blocks(ip);
pblocks = VXFS_BLOCK_PER_PAGE(sbp);
page = pos >> PAGE_CACHE_SHIFT;
offset = pos & ~PAGE_CACHE_MASK;
block = (u_long)(pos >> sbp->s_blocksize_bits) % pblocks;
for (; page < npages; page++, block = 0) {
caddr_t kaddr;
struct page *pp;
pp = vxfs_get_page(ip->i_mapping, page);
if (IS_ERR(pp))
continue;
kaddr = (caddr_t)page_address(pp);
for (; block <= nblocks && block <= pblocks; block++) {
caddr_t baddr, limit;
struct vxfs_dirblk *dbp;
struct vxfs_direct *de;
baddr = kaddr + (block * bsize);
limit = baddr + bsize - VXFS_DIRLEN(1);
dbp = (struct vxfs_dirblk *)baddr;
de = (struct vxfs_direct *)
(offset ?
(kaddr + offset) :
(baddr + VXFS_DIRBLKOV(dbp)));
for (; (caddr_t)de <= limit; de = vxfs_next_entry(de)) {
int over;
if (!de->d_reclen)
break;
if (!de->d_ino)
continue;
offset = (caddr_t)de - kaddr;
over = filler(retp, de->d_name, de->d_namelen,
((page << PAGE_CACHE_SHIFT) | offset) + 2,
de->d_ino, DT_UNKNOWN);
if (over) {
vxfs_put_page(pp);
goto done;
}
}
offset = 0;
}
vxfs_put_page(pp);
offset = 0;
}
done:
fp->f_pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2;
out:
return 0;
}
/**
* vxfs_readdir - read a directory
* @fp: the directory to read
* @retp: return buffer
* @filler: filldir callback
*
* Description:
* vxfs_readdir fills @retp with directory entries from @fp
* using the VFS supplied callback @filler.
*
* Returns:
* Zero.
*/
static int
vxfs_readdir(struct file *fp, struct dir_context *ctx)
{
struct inode *ip = file_inode(fp);
struct super_block *sbp = ip->i_sb;
u_long bsize = sbp->s_blocksize;
loff_t pos, limit;
struct vxfs_sb_info *sbi = VXFS_SBI(sbp);
if (ctx->pos == 0) {
if (!dir_emit_dot(fp, ctx))
goto out;
ctx->pos++;
}
if (ctx->pos == 1) {
if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
goto out;
ctx->pos++;
}
limit = VXFS_DIRROUND(ip->i_size);
if (ctx->pos > limit)
goto out;
pos = ctx->pos & ~3L;
while (pos < limit) {
struct page *pp;
char *kaddr;
int pg_ofs = pos & ~PAGE_MASK;
int rc = 0;
pp = vxfs_get_page(ip->i_mapping, pos >> PAGE_SHIFT);
if (IS_ERR(pp))
return -ENOMEM;
kaddr = (char *)page_address(pp);
while (pg_ofs < PAGE_SIZE && pos < limit) {
struct vxfs_direct *de;
if ((pos & (bsize - 1)) < 4) {
struct vxfs_dirblk *dbp =
(struct vxfs_dirblk *)
(kaddr + (pos & ~PAGE_MASK));
int overhead = VXFS_DIRBLKOV(sbi, dbp);
pos += overhead;
pg_ofs += overhead;
}
de = (struct vxfs_direct *)(kaddr + pg_ofs);
if (!de->d_reclen) {
pos += bsize - 1;
pos &= ~(bsize - 1);
break;
}
pg_ofs += fs16_to_cpu(sbi, de->d_reclen);
pos += fs16_to_cpu(sbi, de->d_reclen);
if (!de->d_ino)
continue;
rc = dir_emit(ctx, de->d_name,
fs16_to_cpu(sbi, de->d_namelen),
fs32_to_cpu(sbi, de->d_ino),
DT_UNKNOWN);
if (!rc) {
/* the dir entry was not read, fix pos. */
pos -= fs16_to_cpu(sbi, de->d_reclen);
break;
}
}
vxfs_put_page(pp);
if (!rc)
break;
}
ctx->pos = pos | 2;
out:
return 0;
}
/**
* vxfs_readdir - read a directory
* @fp: the directory to read
* @retp: return buffer
* @filler: filldir callback
*
* Description:
* vxfs_readdir fills @retp with directory entries from @fp
* using the VFS supplied callback @filler.
*
* Returns:
* Zero.
*/
static int
vxfs_readdir(struct file *fp, struct dir_context *ctx)
{
struct inode *ip = file_inode(fp);
struct super_block *sbp = ip->i_sb;
u_long bsize = sbp->s_blocksize;
u_long page, npages, block, pblocks, nblocks, offset;
loff_t pos;
if (ctx->pos == 0) {
if (!dir_emit_dot(fp, ctx))
return 0;
ctx->pos = 1;
}
if (ctx->pos == 1) {
if (!dir_emit(ctx, "..", 2, VXFS_INO(ip)->vii_dotdot, DT_DIR))
return 0;
ctx->pos = 2;
}
pos = ctx->pos - 2;
if (pos > VXFS_DIRROUND(ip->i_size))
return 0;
npages = dir_pages(ip);
nblocks = dir_blocks(ip);
pblocks = VXFS_BLOCK_PER_PAGE(sbp);
page = pos >> PAGE_CACHE_SHIFT;
offset = pos & ~PAGE_CACHE_MASK;
block = (u_long)(pos >> sbp->s_blocksize_bits) % pblocks;
for (; page < npages; page++, block = 0) {
char *kaddr;
struct page *pp;
pp = vxfs_get_page(ip->i_mapping, page);
if (IS_ERR(pp))
continue;
kaddr = (char *)page_address(pp);
for (; block <= nblocks && block <= pblocks; block++) {
char *baddr, *limit;
struct vxfs_dirblk *dbp;
struct vxfs_direct *de;
baddr = kaddr + (block * bsize);
limit = baddr + bsize - VXFS_DIRLEN(1);
dbp = (struct vxfs_dirblk *)baddr;
de = (struct vxfs_direct *)
(offset ?
(kaddr + offset) :
(baddr + VXFS_DIRBLKOV(dbp)));
for (; (char *)de <= limit; de = vxfs_next_entry(de)) {
if (!de->d_reclen)
break;
if (!de->d_ino)
continue;
offset = (char *)de - kaddr;
ctx->pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2;
if (!dir_emit(ctx, de->d_name, de->d_namelen,
de->d_ino, DT_UNKNOWN)) {
vxfs_put_page(pp);
return 0;
}
}
offset = 0;
}
vxfs_put_page(pp);
offset = 0;
}
ctx->pos = ((page << PAGE_CACHE_SHIFT) | offset) + 2;
return 0;
}