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Commit 9ac3d3e8 authored by Al Viro's avatar Al Viro
Browse files

nfs: switch to ->iterate_shared() 



aside of the usual care about seeding dcache from readdir, we need
to be careful about the pagecache evictions here.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 9cf843e3

fs/nfs/dir.c

+43 −28
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ static void nfs_readdir_clear_array(struct page*); 
const struct file_operations nfs_dir_operations = {

	.llseek		= nfs_llseek_dir,

	.read		= generic_read_dir,

	.iterate	= nfs_readdir,

	.iterate_shared	= nfs_readdir,

	.open		= nfs_opendir,

	.release	= nfs_closedir,

	.fsync		= nfs_fsync_dir,
@@ -145,6 +145,7 @@ struct nfs_cache_array_entry { 
};



struct nfs_cache_array {

	atomic_t refcount;

	int size;

	int eof_index;

	u64 last_cookie;
@@ -200,11 +201,20 @@ void nfs_readdir_clear_array(struct page *page) 
	int i;



	array = kmap_atomic(page);

	if (atomic_dec_and_test(&array->refcount))

		for (i = 0; i < array->size; i++)

			kfree(array->array[i].string.name);

	kunmap_atomic(array);

}



static bool grab_page(struct page *page)

{

	struct nfs_cache_array *array = kmap_atomic(page);

	bool res = atomic_inc_not_zero(&array->refcount);

	kunmap_atomic(array);

	return res;

}



/*

 * the caller is responsible for freeing qstr.name

 * when called by nfs_readdir_add_to_array, the strings will be freed in
@@ -470,6 +480,7 @@ static 
void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)

{

	struct qstr filename = QSTR_INIT(entry->name, entry->len);

	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);

	struct dentry *dentry;

	struct dentry *alias;

	struct inode *dir = d_inode(parent);
@@ -489,7 +500,13 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) 
	filename.hash = full_name_hash(filename.name, filename.len);



	dentry = d_lookup(parent, &filename);

	if (dentry != NULL) {

again:

	if (!dentry) {

		dentry = d_alloc_parallel(parent, &filename, &wq);

		if (IS_ERR(dentry))

			return;

	}

	if (!d_in_lookup(dentry)) {

		/* Is there a mountpoint here? If so, just exit */

		if (!nfs_fsid_equal(&NFS_SB(dentry->d_sb)->fsid,

					&entry->fattr->fsid))
@@ -503,26 +520,21 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) 
		} else {

			d_invalidate(dentry);

			dput(dentry);

			dentry = NULL;

			goto again;

		}

	}



	dentry = d_alloc(parent, &filename);

	if (dentry == NULL)

		return;



	inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label);

	if (IS_ERR(inode))

		goto out;



	alias = d_splice_alias(inode, dentry);

	d_lookup_done(dentry);

	if (alias) {

		if (IS_ERR(alias))

			goto out;

	else if (alias) {

		nfs_set_verifier(alias, nfs_save_change_attribute(dir));

		dput(alias);

	} else

		dput(dentry);

		dentry = alias;

	}

	nfs_set_verifier(dentry, nfs_save_change_attribute(dir));



out:

	dput(dentry);

}
@@ -643,6 +655,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, 
		goto out_label_free;

	}

	memset(array, 0, sizeof(struct nfs_cache_array));

	atomic_set(&array->refcount, 1);

	array->eof_index = -1;



	status = nfs_readdir_alloc_pages(pages, array_size);
@@ -705,7 +718,6 @@ int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page) 
static

void cache_page_release(nfs_readdir_descriptor_t *desc)

{

	if (!desc->page->mapping)

	nfs_readdir_clear_array(desc->page);

	put_page(desc->page);

	desc->page = NULL;
@@ -714,8 +726,16 @@ void cache_page_release(nfs_readdir_descriptor_t *desc) 
static

struct page *get_cache_page(nfs_readdir_descriptor_t *desc)

{

	return read_cache_page(file_inode(desc->file)->i_mapping,

	struct page *page;



	for (;;) {

		page = read_cache_page(file_inode(desc->file)->i_mapping,

			desc->page_index, (filler_t *)nfs_readdir_filler, desc);

		if (IS_ERR(page) || grab_page(page))

			break;

		put_page(page);

	}

	return page;

}



/*
@@ -934,13 +954,11 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx) 


static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)

{

	struct inode *inode = file_inode(filp);

	struct nfs_open_dir_context *dir_ctx = filp->private_data;



	dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n",

			filp, offset, whence);



	inode_lock(inode);

	switch (whence) {

		case 1:

			offset += filp->f_pos;
@@ -948,16 +966,13 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence) 
			if (offset >= 0)

				break;

		default:

			offset = -EINVAL;

			goto out;

			return -EINVAL;

	}

	if (offset != filp->f_pos) {

		filp->f_pos = offset;

		dir_ctx->dir_cookie = 0;

		dir_ctx->duped = 0;

	}

out:

	inode_unlock(inode);

	return offset;

}