Commit 5e993e25 authored by Al Viro's avatar Al Viro
Browse files

ncpfs: get rid of d_validate() nonsense 



What we want is to have non-counting references to children in
pagecache of parent directory, and avoid picking them after a child
has been freed.  Fine, so let's just have ->d_prune() clear
parent's inode "has directory contents in page cache" flag.
That way we don't need ->d_fsdata for storing offsets, so we can
use it as a quick and dirty "is it referenced from page cache"
flag.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent ad52184b

fs/ncpfs/dir.c

+51 −47
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ static int ncp_hash_dentry(const struct dentry *, struct qstr *); 
static int ncp_compare_dentry(const struct dentry *, const struct dentry *,

		unsigned int, const char *, const struct qstr *);

static int ncp_delete_dentry(const struct dentry *);

static void ncp_d_prune(struct dentry *dentry);



const struct dentry_operations ncp_dentry_operations =

{
@@ -84,6 +85,7 @@ const struct dentry_operations ncp_dentry_operations = 
	.d_hash		= ncp_hash_dentry,

	.d_compare	= ncp_compare_dentry,

	.d_delete	= ncp_delete_dentry,

	.d_prune	= ncp_d_prune,

};



#define ncp_namespace(i)	(NCP_SERVER(i)->name_space[NCP_FINFO(i)->volNumber])
@@ -384,42 +386,6 @@ finished: 
	return val;

}



static struct dentry *

ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)

{

	struct dentry *dent = dentry;



	if (d_validate(dent, parent)) {

		if (dent->d_name.len <= NCP_MAXPATHLEN &&

		    (unsigned long)dent->d_fsdata == fpos) {

			if (!dent->d_inode) {

				dput(dent);

				dent = NULL;

			}

			return dent;

		}

		dput(dent);

	}



	/* If a pointer is invalid, we search the dentry. */

	spin_lock(&parent->d_lock);

	list_for_each_entry(dent, &parent->d_subdirs, d_child) {

		if ((unsigned long)dent->d_fsdata == fpos) {

			if (dent->d_inode)

				dget(dent);

			else

				dent = NULL;

			spin_unlock(&parent->d_lock);

			goto out;

		}

	}

	spin_unlock(&parent->d_lock);

	return NULL;



out:

	return dent;

}



static time_t ncp_obtain_mtime(struct dentry *dentry)

{

	struct inode *inode = dentry->d_inode;
@@ -435,6 +401,20 @@ static time_t ncp_obtain_mtime(struct dentry *dentry) 
	return ncp_date_dos2unix(i.modifyTime, i.modifyDate);

}



static inline void

ncp_invalidate_dircache_entries(struct dentry *parent)

{

	struct ncp_server *server = NCP_SERVER(parent->d_inode);

	struct dentry *dentry;



	spin_lock(&parent->d_lock);

	list_for_each_entry(dentry, &parent->d_subdirs, d_child) {

		dentry->d_fsdata = NULL;

		ncp_age_dentry(server, dentry);

	}

	spin_unlock(&parent->d_lock);

}



static int ncp_readdir(struct file *file, struct dir_context *ctx)

{

	struct dentry *dentry = file->f_path.dentry;
@@ -500,10 +480,21 @@ static int ncp_readdir(struct file *file, struct dir_context *ctx) 
			struct dentry *dent;

			bool over;



			dent = ncp_dget_fpos(ctl.cache->dentry[ctl.idx],

						dentry, ctx->pos);

			if (!dent)

			spin_lock(&dentry->d_lock);

			if (!(NCP_FINFO(inode)->flags & NCPI_DIR_CACHE)) { 

				spin_unlock(&dentry->d_lock);

				goto invalid_cache;

			}

			dent = ctl.cache->dentry[ctl.idx];

			if (unlikely(!lockref_get_not_dead(&dent->d_lockref))) {

				spin_unlock(&dentry->d_lock);

				goto invalid_cache;

			}

			spin_unlock(&dentry->d_lock);

			if (!dent->d_inode) {

				dput(dent);

				goto invalid_cache;

			}

			over = !dir_emit(ctx, dent->d_name.name,

					dent->d_name.len,

					dent->d_inode->i_ino, DT_UNKNOWN);
@@ -548,6 +539,9 @@ init_cache: 
	ctl.filled = 0;

	ctl.valid  = 1;

read_really:

	spin_lock(&dentry->d_lock);

	NCP_FINFO(inode)->flags |= NCPI_DIR_CACHE;

	spin_unlock(&dentry->d_lock);

	if (ncp_is_server_root(inode)) {

		ncp_read_volume_list(file, ctx, &ctl);

	} else {
@@ -573,6 +567,13 @@ out: 
	return result;

}



static void ncp_d_prune(struct dentry *dentry)

{

	if (!dentry->d_fsdata)	/* not referenced from page cache */

		return;

	NCP_FINFO(dentry->d_parent->d_inode)->flags &= ~NCPI_DIR_CACHE;

}



static int

ncp_fill_cache(struct file *file, struct dir_context *ctx,

		struct ncp_cache_control *ctrl, struct ncp_entry_info *entry,
@@ -630,6 +631,10 @@ ncp_fill_cache(struct file *file, struct dir_context *ctx, 
			d_instantiate(newdent, inode);

			if (!hashed)

				d_rehash(newdent);

		} else {

			spin_lock(&dentry->d_lock);

			NCP_FINFO(inode)->flags &= ~NCPI_DIR_CACHE;

			spin_unlock(&dentry->d_lock);

		}

	} else {

		struct inode *inode = newdent->d_inode;
@@ -639,12 +644,6 @@ ncp_fill_cache(struct file *file, struct dir_context *ctx, 
		mutex_unlock(&inode->i_mutex);

	}



	if (newdent->d_inode) {

		ino = newdent->d_inode->i_ino;

		newdent->d_fsdata = (void *) ctl.fpos;

		ncp_new_dentry(newdent);

	}



	if (ctl.idx >= NCP_DIRCACHE_SIZE) {

		if (ctl.page) {

			kunmap(ctl.page);
@@ -660,7 +659,12 @@ ncp_fill_cache(struct file *file, struct dir_context *ctx, 
			ctl.cache = kmap(ctl.page);

	}

	if (ctl.cache) {

		if (newdent->d_inode) {

			newdent->d_fsdata = newdent;

			ctl.cache->dentry[ctl.idx] = newdent;

			ino = newdent->d_inode->i_ino;

			ncp_new_dentry(newdent);

		}

 		valid = 1;

	}

	dput(newdent);

fs/ncpfs/ncp_fs_i.h

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ struct ncp_inode_info { 
	int	access;

	int	flags;

#define NCPI_KLUDGE_SYMLINK	0x0001

#define NCPI_DIR_CACHE		0x0002

	__u8	file_handle[6];

	struct inode vfs_inode;

};

fs/ncpfs/ncplib_kernel.h

+0 −30
Original line number Diff line number Diff line
@@ -184,36 +184,6 @@ ncp_new_dentry(struct dentry* dentry) 
	dentry->d_time = jiffies;

}



static inline void

ncp_renew_dentries(struct dentry *parent)

{

	struct ncp_server *server = NCP_SERVER(parent->d_inode);

	struct dentry *dentry;



	spin_lock(&parent->d_lock);

	list_for_each_entry(dentry, &parent->d_subdirs, d_child) {

		if (dentry->d_fsdata == NULL)

			ncp_age_dentry(server, dentry);

		else

			ncp_new_dentry(dentry);

	}

	spin_unlock(&parent->d_lock);

}



static inline void

ncp_invalidate_dircache_entries(struct dentry *parent)

{

	struct ncp_server *server = NCP_SERVER(parent->d_inode);

	struct dentry *dentry;



	spin_lock(&parent->d_lock);

	list_for_each_entry(dentry, &parent->d_subdirs, d_child) {

		dentry->d_fsdata = NULL;

		ncp_age_dentry(server, dentry);

	}

	spin_unlock(&parent->d_lock);

}



struct ncp_cache_head {

	time_t		mtime;

	unsigned long	time;	/* cache age */

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