Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 666 insertions, 0 deletions

diff --git a/fs/afs/dir.c b/fs/afs/dir.c
new file mode 100644
index 000000000000..6682d6d7f294
--- /dev/null
+++ b/fs/afs/dir.c
@@ -0,0 +1,666 @@
+/* dir.c: AFS filesystem directory handling
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/smp_lock.h>
+#include "vnode.h"
+#include "volume.h"
+#include <rxrpc/call.h>
+#include "super.h"
+#include "internal.h"
+
+static struct dentry *afs_dir_lookup(struct inode *dir, struct dentry *dentry,
+				     struct nameidata *nd);
+static int afs_dir_open(struct inode *inode, struct file *file);
+static int afs_dir_readdir(struct file *file, void *dirent, filldir_t filldir);
+static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd);
+static int afs_d_delete(struct dentry *dentry);
+static int afs_dir_lookup_filldir(void *_cookie, const char *name, int nlen,
+				  loff_t fpos, ino_t ino, unsigned dtype);
+
+struct file_operations afs_dir_file_operations = {
+	.open		= afs_dir_open,
+	.readdir	= afs_dir_readdir,
+};
+
+struct inode_operations afs_dir_inode_operations = {
+	.lookup		= afs_dir_lookup,
+	.getattr	= afs_inode_getattr,
+#if 0 /* TODO */
+	.create		= afs_dir_create,
+	.link		= afs_dir_link,
+	.unlink		= afs_dir_unlink,
+	.symlink	= afs_dir_symlink,
+	.mkdir		= afs_dir_mkdir,
+	.rmdir		= afs_dir_rmdir,
+	.mknod		= afs_dir_mknod,
+	.rename		= afs_dir_rename,
+#endif
+};
+
+static struct dentry_operations afs_fs_dentry_operations = {
+	.d_revalidate	= afs_d_revalidate,
+	.d_delete	= afs_d_delete,
+};
+
+#define AFS_DIR_HASHTBL_SIZE	128
+#define AFS_DIR_DIRENT_SIZE	32
+#define AFS_DIRENT_PER_BLOCK	64
+
+union afs_dirent {
+	struct {
+		uint8_t		valid;
+		uint8_t		unused[1];
+		__be16		hash_next;
+		__be32		vnode;
+		__be32		unique;
+		uint8_t		name[16];
+		uint8_t		overflow[4];	/* if any char of the name (inc
+						 * NUL) reaches here, consume
+						 * the next dirent too */
+	} u;
+	uint8_t	extended_name[32];
+};
+
+/* AFS directory page header (one at the beginning of every 2048-byte chunk) */
+struct afs_dir_pagehdr {
+	__be16		npages;
+	__be16		magic;
+#define AFS_DIR_MAGIC htons(1234)
+	uint8_t		nentries;
+	uint8_t		bitmap[8];
+	uint8_t		pad[19];
+};
+
+/* directory block layout */
+union afs_dir_block {
+
+	struct afs_dir_pagehdr pagehdr;
+
+	struct {
+		struct afs_dir_pagehdr	pagehdr;
+		uint8_t			alloc_ctrs[128];
+		/* dir hash table */
+		uint16_t		hashtable[AFS_DIR_HASHTBL_SIZE];
+	} hdr;
+
+	union afs_dirent dirents[AFS_DIRENT_PER_BLOCK];
+};
+
+/* layout on a linux VM page */
+struct afs_dir_page {
+	union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)];
+};
+
+struct afs_dir_lookup_cookie {
+	struct afs_fid	fid;
+	const char	*name;
+	size_t		nlen;
+	int		found;
+};
+
+/*****************************************************************************/
+/*
+ * check that a directory page is valid
+ */
+static inline void afs_dir_check_page(struct inode *dir, struct page *page)
+{
+	struct afs_dir_page *dbuf;
+	loff_t latter;
+	int tmp, qty;
+
+#if 0
+	/* check the page count */
+	qty = desc.size / sizeof(dbuf->blocks[0]);
+	if (qty == 0)
+		goto error;
+
+	if (page->index==0 && qty!=ntohs(dbuf->blocks[0].pagehdr.npages)) {
+		printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n",
+		       __FUNCTION__,dir->i_ino,qty,ntohs(dbuf->blocks[0].pagehdr.npages));
+		goto error;
+	}
+#endif
+
+	/* determine how many magic numbers there should be in this page */
+	latter = dir->i_size - (page->index << PAGE_CACHE_SHIFT);
+	if (latter >= PAGE_SIZE)
+		qty = PAGE_SIZE;
+	else
+		qty = latter;
+	qty /= sizeof(union afs_dir_block);
+
+	/* check them */
+	dbuf = page_address(page);
+	for (tmp = 0; tmp < qty; tmp++) {
+		if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
+			printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n",
+			       __FUNCTION__, dir->i_ino, tmp, qty,
+			       ntohs(dbuf->blocks[tmp].pagehdr.magic));
+			goto error;
+		}
+	}
+
+	SetPageChecked(page);
+	return;
+
+ error:
+	SetPageChecked(page);
+	SetPageError(page);
+
+} /* end afs_dir_check_page() */
+
+/*****************************************************************************/
+/*
+ * discard a page cached in the pagecache
+ */
+static inline void afs_dir_put_page(struct page *page)
+{
+	kunmap(page);
+	page_cache_release(page);
+
+} /* end afs_dir_put_page() */
+
+/*****************************************************************************/
+/*
+ * get a page into the pagecache
+ */
+static struct page *afs_dir_get_page(struct inode *dir, unsigned long index)
+{
+	struct page *page;
+
+	_enter("{%lu},%lu", dir->i_ino, index);
+
+	page = read_cache_page(dir->i_mapping,index,
+			       (filler_t *) dir->i_mapping->a_ops->readpage,
+			       NULL);
+	if (!IS_ERR(page)) {
+		wait_on_page_locked(page);
+		kmap(page);
+		if (!PageUptodate(page))
+			goto fail;
+		if (!PageChecked(page))
+			afs_dir_check_page(dir, page);
+		if (PageError(page))
+			goto fail;
+	}
+	return page;
+
+ fail:
+	afs_dir_put_page(page);
+	return ERR_PTR(-EIO);
+} /* end afs_dir_get_page() */
+
+/*****************************************************************************/
+/*
+ * open an AFS directory file
+ */
+static int afs_dir_open(struct inode *inode, struct file *file)
+{
+	_enter("{%lu}", inode->i_ino);
+
+	BUG_ON(sizeof(union afs_dir_block) != 2048);
+	BUG_ON(sizeof(union afs_dirent) != 32);
+
+	if (AFS_FS_I(inode)->flags & AFS_VNODE_DELETED)
+		return -ENOENT;
+
+	_leave(" = 0");
+	return 0;
+
+} /* end afs_dir_open() */
+
+/*****************************************************************************/
+/*
+ * deal with one block in an AFS directory
+ */
+static int afs_dir_iterate_block(unsigned *fpos,
+				 union afs_dir_block *block,
+				 unsigned blkoff,
+				 void *cookie,
+				 filldir_t filldir)
+{
+	union afs_dirent *dire;
+	unsigned offset, next, curr;
+	size_t nlen;
+	int tmp, ret;
+
+	_enter("%u,%x,%p,,",*fpos,blkoff,block);
+
+	curr = (*fpos - blkoff) / sizeof(union afs_dirent);
+
+	/* walk through the block, an entry at a time */
+	for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
+	     offset < AFS_DIRENT_PER_BLOCK;
+	     offset = next
+	     ) {
+		next = offset + 1;
+
+		/* skip entries marked unused in the bitmap */
+		if (!(block->pagehdr.bitmap[offset / 8] &
+		      (1 << (offset % 8)))) {
+			_debug("ENT[%Zu.%u]: unused\n",
+			       blkoff / sizeof(union afs_dir_block), offset);
+			if (offset >= curr)
+				*fpos = blkoff +
+					next * sizeof(union afs_dirent);
+			continue;
+		}
+
+		/* got a valid entry */
+		dire = &block->dirents[offset];
+		nlen = strnlen(dire->u.name,
+			       sizeof(*block) -
+			       offset * sizeof(union afs_dirent));
+
+		_debug("ENT[%Zu.%u]: %s %Zu \"%s\"\n",
+		       blkoff / sizeof(union afs_dir_block), offset,
+		       (offset < curr ? "skip" : "fill"),
+		       nlen, dire->u.name);
+
+		/* work out where the next possible entry is */
+		for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
+			if (next >= AFS_DIRENT_PER_BLOCK) {
+				_debug("ENT[%Zu.%u]:"
+				       " %u travelled beyond end dir block"
+				       " (len %u/%Zu)\n",
+				       blkoff / sizeof(union afs_dir_block),
+				       offset, next, tmp, nlen);
+				return -EIO;
+			}
+			if (!(block->pagehdr.bitmap[next / 8] &
+			      (1 << (next % 8)))) {
+				_debug("ENT[%Zu.%u]:"
+				       " %u unmarked extension (len %u/%Zu)\n",
+				       blkoff / sizeof(union afs_dir_block),
+				       offset, next, tmp, nlen);
+				return -EIO;
+			}
+
+			_debug("ENT[%Zu.%u]: ext %u/%Zu\n",
+			       blkoff / sizeof(union afs_dir_block),
+			       next, tmp, nlen);
+			next++;
+		}
+
+		/* skip if starts before the current position */
+		if (offset < curr)
+			continue;
+
+		/* found the next entry */
+		ret = filldir(cookie,
+			      dire->u.name,
+			      nlen,
+			      blkoff + offset * sizeof(union afs_dirent),
+			      ntohl(dire->u.vnode),
+			      filldir == afs_dir_lookup_filldir ?
+			      ntohl(dire->u.unique) : DT_UNKNOWN);
+		if (ret < 0) {
+			_leave(" = 0 [full]");
+			return 0;
+		}
+
+		*fpos = blkoff + next * sizeof(union afs_dirent);
+	}
+
+	_leave(" = 1 [more]");
+	return 1;
+} /* end afs_dir_iterate_block() */
+
+/*****************************************************************************/
+/*
+ * read an AFS directory
+ */
+static int afs_dir_iterate(struct inode *dir, unsigned *fpos, void *cookie,
+			   filldir_t filldir)
+{
+	union afs_dir_block	*dblock;
+	struct afs_dir_page *dbuf;
+	struct page *page;
+	unsigned blkoff, limit;
+	int ret;
+
+	_enter("{%lu},%u,,", dir->i_ino, *fpos);
+
+	if (AFS_FS_I(dir)->flags & AFS_VNODE_DELETED) {
+		_leave(" = -ESTALE");
+		return -ESTALE;
+	}
+
+	/* round the file position up to the next entry boundary */
+	*fpos += sizeof(union afs_dirent) - 1;
+	*fpos &= ~(sizeof(union afs_dirent) - 1);
+
+	/* walk through the blocks in sequence */
+	ret = 0;
+	while (*fpos < dir->i_size) {
+		blkoff = *fpos & ~(sizeof(union afs_dir_block) - 1);
+
+		/* fetch the appropriate page from the directory */
+		page = afs_dir_get_page(dir, blkoff / PAGE_SIZE);
+		if (IS_ERR(page)) {
+			ret = PTR_ERR(page);
+			break;
+		}
+
+		limit = blkoff & ~(PAGE_SIZE - 1);
+
+		dbuf = page_address(page);
+
+		/* deal with the individual blocks stashed on this page */
+		do {
+			dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
+					       sizeof(union afs_dir_block)];
+			ret = afs_dir_iterate_block(fpos, dblock, blkoff,
+						    cookie, filldir);
+			if (ret != 1) {
+				afs_dir_put_page(page);
+				goto out;
+			}
+
+			blkoff += sizeof(union afs_dir_block);
+
+		} while (*fpos < dir->i_size && blkoff < limit);
+
+		afs_dir_put_page(page);
+		ret = 0;
+	}
+
+ out:
+	_leave(" = %d", ret);
+	return ret;
+} /* end afs_dir_iterate() */
+
+/*****************************************************************************/
+/*
+ * read an AFS directory
+ */
+static int afs_dir_readdir(struct file *file, void *cookie, filldir_t filldir)
+{
+	unsigned fpos;
+	int ret;
+
+	_enter("{%Ld,{%lu}}", file->f_pos, file->f_dentry->d_inode->i_ino);
+
+	fpos = file->f_pos;
+	ret = afs_dir_iterate(file->f_dentry->d_inode, &fpos, cookie, filldir);
+	file->f_pos = fpos;
+
+	_leave(" = %d", ret);
+	return ret;
+} /* end afs_dir_readdir() */
+
+/*****************************************************************************/
+/*
+ * search the directory for a name
+ * - if afs_dir_iterate_block() spots this function, it'll pass the FID
+ *   uniquifier through dtype
+ */
+static int afs_dir_lookup_filldir(void *_cookie, const char *name, int nlen,
+				  loff_t fpos, ino_t ino, unsigned dtype)
+{
+	struct afs_dir_lookup_cookie *cookie = _cookie;
+
+	_enter("{%s,%Zu},%s,%u,,%lu,%u",
+	       cookie->name, cookie->nlen, name, nlen, ino, dtype);
+
+	if (cookie->nlen != nlen || memcmp(cookie->name, name, nlen) != 0) {
+		_leave(" = 0 [no]");
+		return 0;
+	}
+
+	cookie->fid.vnode = ino;
+	cookie->fid.unique = dtype;
+	cookie->found = 1;
+
+	_leave(" = -1 [found]");
+	return -1;
+} /* end afs_dir_lookup_filldir() */
+
+/*****************************************************************************/
+/*
+ * look up an entry in a directory
+ */
+static struct dentry *afs_dir_lookup(struct inode *dir, struct dentry *dentry,
+				     struct nameidata *nd)
+{
+	struct afs_dir_lookup_cookie cookie;
+	struct afs_super_info *as;
+	struct afs_vnode *vnode;
+	struct inode *inode;
+	unsigned fpos;
+	int ret;
+
+	_enter("{%lu},%p{%s}", dir->i_ino, dentry, dentry->d_name.name);
+
+	/* insanity checks first */
+	BUG_ON(sizeof(union afs_dir_block) != 2048);
+	BUG_ON(sizeof(union afs_dirent) != 32);
+
+	if (dentry->d_name.len > 255) {
+		_leave(" = -ENAMETOOLONG");
+		return ERR_PTR(-ENAMETOOLONG);
+	}
+
+	vnode = AFS_FS_I(dir);
+	if (vnode->flags & AFS_VNODE_DELETED) {
+		_leave(" = -ESTALE");
+		return ERR_PTR(-ESTALE);
+	}
+
+	as = dir->i_sb->s_fs_info;
+
+	/* search the directory */
+	cookie.name	= dentry->d_name.name;
+	cookie.nlen	= dentry->d_name.len;
+	cookie.fid.vid	= as->volume->vid;
+	cookie.found	= 0;
+
+	fpos = 0;
+	ret = afs_dir_iterate(dir, &fpos, &cookie, afs_dir_lookup_filldir);
+	if (ret < 0) {
+		_leave(" = %d", ret);
+		return ERR_PTR(ret);
+	}
+
+	ret = -ENOENT;
+	if (!cookie.found) {
+		_leave(" = %d", ret);
+		return ERR_PTR(ret);
+	}
+
+	/* instantiate the dentry */
+	ret = afs_iget(dir->i_sb, &cookie.fid, &inode);
+	if (ret < 0) {
+		_leave(" = %d", ret);
+		return ERR_PTR(ret);
+	}
+
+	dentry->d_op = &afs_fs_dentry_operations;
+	dentry->d_fsdata = (void *) (unsigned long) vnode->status.version;
+
+	d_add(dentry, inode);
+	_leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%lu }",
+	       cookie.fid.vnode,
+	       cookie.fid.unique,
+	       dentry->d_inode->i_ino,
+	       dentry->d_inode->i_version);
+
+	return NULL;
+} /* end afs_dir_lookup() */
+
+/*****************************************************************************/
+/*
+ * check that a dentry lookup hit has found a valid entry
+ * - NOTE! the hit can be a negative hit too, so we can't assume we have an
+ *   inode
+ * (derived from nfs_lookup_revalidate)
+ */
+static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	struct afs_dir_lookup_cookie cookie;
+	struct dentry *parent;
+	struct inode *inode, *dir;
+	unsigned fpos;
+	int ret;
+
+	_enter("{sb=%p n=%s},", dentry->d_sb, dentry->d_name.name);
+
+	/* lock down the parent dentry so we can peer at it */
+	parent = dget_parent(dentry->d_parent);
+
+	dir = parent->d_inode;
+	inode = dentry->d_inode;
+
+	/* handle a negative dentry */
+	if (!inode)
+		goto out_bad;
+
+	/* handle a bad inode */
+	if (is_bad_inode(inode)) {
+		printk("kAFS: afs_d_revalidate: %s/%s has bad inode\n",
+		       dentry->d_parent->d_name.name, dentry->d_name.name);
+		goto out_bad;
+	}
+
+	/* force a full look up if the parent directory changed since last the
+	 * server was consulted
+	 * - otherwise this inode must still exist, even if the inode details
+	 *   themselves have changed
+	 */
+	if (AFS_FS_I(dir)->flags & AFS_VNODE_CHANGED)
+		afs_vnode_fetch_status(AFS_FS_I(dir));
+
+	if (AFS_FS_I(dir)->flags & AFS_VNODE_DELETED) {
+		_debug("%s: parent dir deleted", dentry->d_name.name);
+		goto out_bad;
+	}
+
+	if (AFS_FS_I(inode)->flags & AFS_VNODE_DELETED) {
+		_debug("%s: file already deleted", dentry->d_name.name);
+		goto out_bad;
+	}
+
+	if ((unsigned long) dentry->d_fsdata !=
+	    (unsigned long) AFS_FS_I(dir)->status.version) {
+		_debug("%s: parent changed %lu -> %u",
+		       dentry->d_name.name,
+		       (unsigned long) dentry->d_fsdata,
+		       (unsigned) AFS_FS_I(dir)->status.version);
+
+		/* search the directory for this vnode */
+		cookie.name	= dentry->d_name.name;
+		cookie.nlen	= dentry->d_name.len;
+		cookie.fid.vid	= AFS_FS_I(inode)->volume->vid;
+		cookie.found	= 0;
+
+		fpos = 0;
+		ret = afs_dir_iterate(dir, &fpos, &cookie,
+				      afs_dir_lookup_filldir);
+		if (ret < 0) {
+			_debug("failed to iterate dir %s: %d",
+			       parent->d_name.name, ret);
+			goto out_bad;
+		}
+
+		if (!cookie.found) {
+			_debug("%s: dirent not found", dentry->d_name.name);
+			goto not_found;
+		}
+
+		/* if the vnode ID has changed, then the dirent points to a
+		 * different file */
+		if (cookie.fid.vnode != AFS_FS_I(inode)->fid.vnode) {
+			_debug("%s: dirent changed", dentry->d_name.name);
+			goto not_found;
+		}
+
+		/* if the vnode ID uniqifier has changed, then the file has
+		 * been deleted */
+		if (cookie.fid.unique != AFS_FS_I(inode)->fid.unique) {
+			_debug("%s: file deleted (uq %u -> %u I:%lu)",
+			       dentry->d_name.name,
+			       cookie.fid.unique,
+			       AFS_FS_I(inode)->fid.unique,
+			       inode->i_version);
+			spin_lock(&AFS_FS_I(inode)->lock);
+			AFS_FS_I(inode)->flags |= AFS_VNODE_DELETED;
+			spin_unlock(&AFS_FS_I(inode)->lock);
+			invalidate_remote_inode(inode);
+			goto out_bad;
+		}
+
+		dentry->d_fsdata =
+			(void *) (unsigned long) AFS_FS_I(dir)->status.version;
+	}
+
+ out_valid:
+	dput(parent);
+	_leave(" = 1 [valid]");
+	return 1;
+
+	/* the dirent, if it exists, now points to a different vnode */
+ not_found:
+	spin_lock(&dentry->d_lock);
+	dentry->d_flags |= DCACHE_NFSFS_RENAMED;
+	spin_unlock(&dentry->d_lock);
+
+ out_bad:
+	if (inode) {
+		/* don't unhash if we have submounts */
+		if (have_submounts(dentry))
+			goto out_valid;
+	}
+
+	shrink_dcache_parent(dentry);
+
+	_debug("dropping dentry %s/%s",
+	       dentry->d_parent->d_name.name, dentry->d_name.name);
+	d_drop(dentry);
+
+	dput(parent);
+
+	_leave(" = 0 [bad]");
+	return 0;
+} /* end afs_d_revalidate() */
+
+/*****************************************************************************/
+/*
+ * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
+ * sleep)
+ * - called from dput() when d_count is going to 0.
+ * - return 1 to request dentry be unhashed, 0 otherwise
+ */
+static int afs_d_delete(struct dentry *dentry)
+{
+	_enter("%s", dentry->d_name.name);
+
+	if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+		goto zap;
+
+	if (dentry->d_inode) {
+		if (AFS_FS_I(dentry->d_inode)->flags & AFS_VNODE_DELETED)
+			goto zap;
+	}
+
+	_leave(" = 0 [keep]");
+	return 0;
+
+ zap:
+	_leave(" = 1 [zap]");
+	return 1;
+} /* end afs_d_delete() */