Commit e5fef2a9 authored by Linus Torvalds's avatar Linus Torvalds
Browse files
Pull AFS updates from David Howells:
 "A set of fix and development patches for AFS for 5.2.

  Summary:

   - Fix the AFS file locking so that sqlite can run on an AFS mount and
     also so that firefox and gnome can use a homedir that's mounted
     through AFS.

     This required emulation of fine-grained locking when the server
     will only support whole-file locks and no upgrade/downgrade. Four
     modes are provided, settable by mount parameter:

       "flock=local"   - No reference to the server

       "flock=openafs" - Fine-grained locks are local-only, whole-file
                         locks require sufficient server locks

       "flock=strict"  - All locks require sufficient server locks

       "flock=write"   - Always get an exclusive server lock

     If the volume is a read-only or backup volume, then flock=local for
     that volume.

   - Log extra information for a couple of cases where the client mucks
     up somehow: AFS vnode with undefined type and dir check failure -
     in both cases we seem to end up with unfilled data, but the issues
     happen infrequently and are difficult to reproduce at will.

   - Implement silly rename for unlink() and rename().

   - Set i_blocks so that du can get some information about usage.

   - Fix xattr handlers to return the right amount of data and to not
     overflow buffers.

   - Implement getting/setting raw AFS and YFS ACLs as xattrs"

* tag 'afs-next-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Implement YFS ACL setting
  afs: Get YFS ACLs and information through xattrs
  afs: implement acl setting
  afs: Get an AFS3 ACL as an xattr
  afs: Fix getting the afs.fid xattr
  afs: Fix the afs.cell and afs.volume xattr handlers
  afs: Calculate i_blocks based on file size
  afs: Log more information for "kAFS: AFS vnode with undefined type\n"
  afs: Provide mount-time configurable byte-range file locking emulation
  afs: Add more tracepoints
  afs: Implement sillyrename for unlink and rename
  afs: Add directory reload tracepoint
  afs: Handle lock rpc ops failing on a file that got deleted
  afs: Improve dir check failure reports
  afs: Add file locking tracepoints
  afs: Further fix file locking
  afs: Fix AFS file locking to allow fine grained locks
  afs: Calculate lock extend timer from set/extend reply reception
  afs: Split wait from afs_make_call()
parents 149e703c f5e45463
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+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ kafs-y := \
	cmservice.o \
	dir.o \
	dir_edit.o \
	dir_silly.o \
	dynroot.o \
	file.o \
	flock.o \
+2 −0
Original line number Diff line number Diff line
@@ -17,8 +17,10 @@

enum AFS_FS_Operations {
	FSFETCHDATA		= 130,	/* AFS Fetch file data */
	FSFETCHACL		= 131,	/* AFS Fetch file ACL */
	FSFETCHSTATUS		= 132,	/* AFS Fetch file status */
	FSSTOREDATA		= 133,	/* AFS Store file data */
	FSSTOREACL		= 134,	/* AFS Store file ACL */
	FSSTORESTATUS		= 135,	/* AFS Store file status */
	FSREMOVEFILE		= 136,	/* AFS Remove a file */
	FSCREATEFILE		= 137,	/* AFS Create a file */
+151 −16
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ static int afs_dir_open(struct inode *inode, struct file *file);
static int afs_readdir(struct file *file, struct dir_context *ctx);
static int afs_d_revalidate(struct dentry *dentry, unsigned int flags);
static int afs_d_delete(const struct dentry *dentry);
static void afs_d_iput(struct dentry *dentry, struct inode *inode);
static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name, int nlen,
				  loff_t fpos, u64 ino, unsigned dtype);
static int afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen,
@@ -85,6 +86,7 @@ const struct dentry_operations afs_fs_dentry_operations = {
	.d_delete	= afs_d_delete,
	.d_release	= afs_d_release,
	.d_automount	= afs_d_automount,
	.d_iput		= afs_d_iput,
};

struct afs_lookup_one_cookie {
@@ -159,6 +161,38 @@ error:
	return false;
}

/*
 * Check the contents of a directory that we've just read.
 */
static bool afs_dir_check_pages(struct afs_vnode *dvnode, struct afs_read *req)
{
	struct afs_xdr_dir_page *dbuf;
	unsigned int i, j, qty = PAGE_SIZE / sizeof(union afs_xdr_dir_block);

	for (i = 0; i < req->nr_pages; i++)
		if (!afs_dir_check_page(dvnode, req->pages[i], req->actual_len))
			goto bad;
	return true;

bad:
	pr_warn("DIR %llx:%llx f=%llx l=%llx al=%llx r=%llx\n",
		dvnode->fid.vid, dvnode->fid.vnode,
		req->file_size, req->len, req->actual_len, req->remain);
	pr_warn("DIR %llx %x %x %x\n",
		req->pos, req->index, req->nr_pages, req->offset);

	for (i = 0; i < req->nr_pages; i++) {
		dbuf = kmap(req->pages[i]);
		for (j = 0; j < qty; j++) {
			union afs_xdr_dir_block *block = &dbuf->blocks[j];

			pr_warn("[%02x] %32phN\n", i * qty + j, block);
		}
		kunmap(req->pages[i]);
	}
	return false;
}

/*
 * open an AFS directory file
 */
@@ -277,6 +311,7 @@ retry:
		goto error;

	if (!test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags)) {
		trace_afs_reload_dir(dvnode);
		ret = afs_fetch_data(dvnode, key, req);
		if (ret < 0)
			goto error_unlock;
@@ -288,9 +323,7 @@ retry:

		/* Validate the data we just read. */
		ret = -EIO;
		for (i = 0; i < req->nr_pages; i++)
			if (!afs_dir_check_page(dvnode, req->pages[i],
						req->actual_len))
		if (!afs_dir_check_pages(dvnode, req))
			goto error_unlock;

		// TODO: Trim excess pages
@@ -743,7 +776,7 @@ success:
		ti = afs_iget(dir->i_sb, key, &cookie->fids[i],
			      &cookie->statuses[i],
			      &cookie->callbacks[i],
			      cbi);
			      cbi, dvnode);
		if (i == 0) {
			inode = ti;
		} else {
@@ -875,8 +908,14 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
			(void *)(unsigned long)dvnode->status.data_version;
	}
	d = d_splice_alias(inode, dentry);
	if (!IS_ERR_OR_NULL(d))
	if (!IS_ERR_OR_NULL(d)) {
		d->d_fsdata = dentry->d_fsdata;
		trace_afs_lookup(dvnode, &d->d_name,
				 inode ? AFS_FS_I(inode) : NULL);
	} else {
		trace_afs_lookup(dvnode, &dentry->d_name,
				 inode ? AFS_FS_I(inode) : NULL);
	}
	return d;
}

@@ -1052,6 +1091,16 @@ zap:
	return 1;
}

/*
 * Clean up sillyrename files on dentry removal.
 */
static void afs_d_iput(struct dentry *dentry, struct inode *inode)
{
	if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
		afs_silly_iput(dentry, inode);
	iput(inode);
}

/*
 * handle dentry release
 */
@@ -1076,7 +1125,7 @@ static void afs_vnode_new_inode(struct afs_fs_cursor *fc,
		return;

	inode = afs_iget(fc->vnode->vfs_inode.i_sb, fc->key,
			 newfid, newstatus, newcb, fc->cbi);
			 newfid, newstatus, newcb, fc->cbi, fc->vnode);
	if (IS_ERR(inode)) {
		/* ENOMEM or EINTR at a really inconvenient time - just abandon
		 * the new directory on the server.
@@ -1194,6 +1243,12 @@ static int afs_rmdir(struct inode *dir, struct dentry *dentry)
			goto error_key;
	}

	if (vnode) {
		ret = down_write_killable(&vnode->rmdir_lock);
		if (ret < 0)
			goto error_key;
	}

	ret = -ERESTARTSYS;
	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
		while (afs_select_fileserver(&fc)) {
@@ -1212,6 +1267,8 @@ static int afs_rmdir(struct inode *dir, struct dentry *dentry)
		}
	}

	if (vnode)
		up_write(&vnode->rmdir_lock);
error_key:
	key_put(key);
error:
@@ -1228,7 +1285,7 @@ error:
 * However, if we didn't have a callback promise outstanding, or it was
 * outstanding on a different server, then it won't break it either...
 */
static int afs_dir_remove_link(struct dentry *dentry, struct key *key,
int afs_dir_remove_link(struct dentry *dentry, struct key *key,
			unsigned long d_version_before,
			unsigned long d_version_after)
{
@@ -1277,6 +1334,7 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
	struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode = NULL;
	struct key *key;
	unsigned long d_version = (unsigned long)dentry->d_fsdata;
	bool need_rehash = false;
	u64 data_version = dvnode->status.data_version;
	int ret;

@@ -1300,6 +1358,21 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
			goto error_key;
	}

	spin_lock(&dentry->d_lock);
	if (vnode && d_count(dentry) > 1) {
		spin_unlock(&dentry->d_lock);
		/* Start asynchronous writeout of the inode */
		write_inode_now(d_inode(dentry), 0);
		ret = afs_sillyrename(dvnode, vnode, dentry, key);
		goto error_key;
	}
	if (!d_unhashed(dentry)) {
		/* Prevent a race with RCU lookup. */
		__d_drop(dentry);
		need_rehash = true;
	}
	spin_unlock(&dentry->d_lock);

	ret = -ERESTARTSYS;
	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
		while (afs_select_fileserver(&fc)) {
@@ -1331,6 +1404,9 @@ static int afs_unlink(struct inode *dir, struct dentry *dentry)
					    afs_edit_dir_for_unlink);
	}

	if (need_rehash && ret < 0 && ret != -ENOENT)
		d_rehash(dentry);

error_key:
	key_put(key);
error:
@@ -1551,6 +1627,8 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
{
	struct afs_fs_cursor fc;
	struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
	struct dentry *tmp = NULL, *rehash = NULL;
	struct inode *new_inode;
	struct key *key;
	u64 orig_data_version, new_data_version;
	bool new_negative = d_is_negative(new_dentry);
@@ -1559,6 +1637,10 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
	if (flags)
		return -EINVAL;

	/* Don't allow silly-rename files be moved around. */
	if (old_dentry->d_flags & DCACHE_NFSFS_RENAMED)
		return -EINVAL;

	vnode = AFS_FS_I(d_inode(old_dentry));
	orig_dvnode = AFS_FS_I(old_dir);
	new_dvnode = AFS_FS_I(new_dir);
@@ -1577,12 +1659,48 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
		goto error;
	}

	/* For non-directories, check whether the target is busy and if so,
	 * make a copy of the dentry and then do a silly-rename.  If the
	 * silly-rename succeeds, the copied dentry is hashed and becomes the
	 * new target.
	 */
	if (d_is_positive(new_dentry) && !d_is_dir(new_dentry)) {
		/* To prevent any new references to the target during the
		 * rename, we unhash the dentry in advance.
		 */
		if (!d_unhashed(new_dentry)) {
			d_drop(new_dentry);
			rehash = new_dentry;
		}

		if (d_count(new_dentry) > 2) {
			/* copy the target dentry's name */
			ret = -ENOMEM;
			tmp = d_alloc(new_dentry->d_parent,
				      &new_dentry->d_name);
			if (!tmp)
				goto error_rehash;

			ret = afs_sillyrename(new_dvnode,
					      AFS_FS_I(d_inode(new_dentry)),
					      new_dentry, key);
			if (ret)
				goto error_rehash;

			new_dentry = tmp;
			rehash = NULL;
			new_negative = true;
			orig_data_version = orig_dvnode->status.data_version;
			new_data_version = new_dvnode->status.data_version;
		}
	}

	ret = -ERESTARTSYS;
	if (afs_begin_vnode_operation(&fc, orig_dvnode, key)) {
		if (orig_dvnode != new_dvnode) {
			if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) {
				afs_end_vnode_operation(&fc);
				goto error_key;
				goto error_rehash;
			}
		}
		while (afs_select_fileserver(&fc)) {
@@ -1599,25 +1717,42 @@ static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
			mutex_unlock(&new_dvnode->io_lock);
		ret = afs_end_vnode_operation(&fc);
		if (ret < 0)
			goto error_key;
			goto error_rehash;
	}

	if (ret == 0) {
		if (rehash)
			d_rehash(rehash);
		if (test_bit(AFS_VNODE_DIR_VALID, &orig_dvnode->flags))
		    afs_edit_dir_remove(orig_dvnode, &old_dentry->d_name,
					afs_edit_dir_for_rename);
					afs_edit_dir_for_rename_0);

		if (!new_negative &&
		    test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags))
			afs_edit_dir_remove(new_dvnode, &new_dentry->d_name,
					    afs_edit_dir_for_rename);
					    afs_edit_dir_for_rename_1);

		if (test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags))
			afs_edit_dir_add(new_dvnode, &new_dentry->d_name,
					 &vnode->fid,  afs_edit_dir_for_rename);
					 &vnode->fid, afs_edit_dir_for_rename_2);

		new_inode = d_inode(new_dentry);
		if (new_inode) {
			spin_lock(&new_inode->i_lock);
			if (new_inode->i_nlink > 0)
				drop_nlink(new_inode);
			spin_unlock(&new_inode->i_lock);
		}
		d_move(old_dentry, new_dentry);
		goto error_tmp;
	}

error_key:
error_rehash:
	if (rehash)
		d_rehash(rehash);
error_tmp:
	if (tmp)
		dput(tmp);
	key_put(key);
error:
	_leave(" = %d", ret);

fs/afs/dir_silly.c

0 → 100644
+239 −0
Original line number Diff line number Diff line
/* AFS silly rename handling
 *
 * Copyright (C) 2019 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 * - Derived from NFS's sillyrename.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/fsnotify.h>
#include "internal.h"

/*
 * Actually perform the silly rename step.
 */
static int afs_do_silly_rename(struct afs_vnode *dvnode, struct afs_vnode *vnode,
			       struct dentry *old, struct dentry *new,
			       struct key *key)
{
	struct afs_fs_cursor fc;
	u64 dir_data_version = dvnode->status.data_version;
	int ret = -ERESTARTSYS;

	_enter("%pd,%pd", old, new);

	trace_afs_silly_rename(vnode, false);
	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
		while (afs_select_fileserver(&fc)) {
			fc.cb_break = afs_calc_vnode_cb_break(dvnode);
			afs_fs_rename(&fc, old->d_name.name,
				      dvnode, new->d_name.name,
				      dir_data_version, dir_data_version);
		}

		afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
		ret = afs_end_vnode_operation(&fc);
	}

	if (ret == 0) {
		spin_lock(&old->d_lock);
		old->d_flags |= DCACHE_NFSFS_RENAMED;
		spin_unlock(&old->d_lock);
		if (dvnode->silly_key != key) {
			key_put(dvnode->silly_key);
			dvnode->silly_key = key_get(key);
		}

		if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
			afs_edit_dir_remove(dvnode, &old->d_name,
					    afs_edit_dir_for_silly_0);
		if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
			afs_edit_dir_add(dvnode, &new->d_name,
					 &vnode->fid, afs_edit_dir_for_silly_1);

		/* vfs_unlink and the like do not issue this when a file is
		 * sillyrenamed, so do it here.
		 */
		fsnotify_nameremove(old, 0);
	}

	_leave(" = %d", ret);
	return ret;
}

/**
 * afs_sillyrename - Perform a silly-rename of a dentry
 *
 * AFS is stateless and the server doesn't know when the client is holding a
 * file open.  To prevent application problems when a file is unlinked while
 * it's still open, the client performs a "silly-rename".  That is, it renames
 * the file to a hidden file in the same directory, and only performs the
 * unlink once the last reference to it is put.
 *
 * The final cleanup is done during dentry_iput.
 */
int afs_sillyrename(struct afs_vnode *dvnode, struct afs_vnode *vnode,
		    struct dentry *dentry, struct key *key)
{
	static unsigned int sillycounter;
	struct dentry *sdentry = NULL;
	unsigned char silly[16];
	int ret = -EBUSY;

	_enter("");

	/* We don't allow a dentry to be silly-renamed twice. */
	if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
		return -EBUSY;

	sdentry = NULL;
	do {
		int slen;

		dput(sdentry);
		sillycounter++;

		/* Create a silly name.  Note that the ".__afs" prefix is
		 * understood by the salvager and must not be changed.
		 */
		slen = scnprintf(silly, sizeof(silly), ".__afs%04X", sillycounter);
		sdentry = lookup_one_len(silly, dentry->d_parent, slen);

		/* N.B. Better to return EBUSY here ... it could be dangerous
		 * to delete the file while it's in use.
		 */
		if (IS_ERR(sdentry))
			goto out;
	} while (!d_is_negative(sdentry));

	ihold(&vnode->vfs_inode);

	ret = afs_do_silly_rename(dvnode, vnode, dentry, sdentry, key);
	switch (ret) {
	case 0:
		/* The rename succeeded. */
		d_move(dentry, sdentry);
		break;
	case -ERESTARTSYS:
		/* The result of the rename is unknown. Play it safe by forcing
		 * a new lookup.
		 */
		d_drop(dentry);
		d_drop(sdentry);
	}

	iput(&vnode->vfs_inode);
	dput(sdentry);
out:
	_leave(" = %d", ret);
	return ret;
}

/*
 * Tell the server to remove a sillyrename file.
 */
static int afs_do_silly_unlink(struct afs_vnode *dvnode, struct afs_vnode *vnode,
			       struct dentry *dentry, struct key *key)
{
	struct afs_fs_cursor fc;
	u64 dir_data_version = dvnode->status.data_version;
	int ret = -ERESTARTSYS;

	_enter("");

	trace_afs_silly_rename(vnode, true);
	if (afs_begin_vnode_operation(&fc, dvnode, key)) {
		while (afs_select_fileserver(&fc)) {
			fc.cb_break = afs_calc_vnode_cb_break(dvnode);

			if (test_bit(AFS_SERVER_FL_IS_YFS, &fc.cbi->server->flags) &&
			    !test_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags)) {
				yfs_fs_remove_file2(&fc, vnode, dentry->d_name.name,
						    dir_data_version);
				if (fc.ac.error != -ECONNABORTED ||
				    fc.ac.abort_code != RXGEN_OPCODE)
					continue;
				set_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags);
			}

			afs_fs_remove(&fc, vnode, dentry->d_name.name, false,
				      dir_data_version);
		}

		afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
		ret = afs_end_vnode_operation(&fc);
		if (ret == 0) {
			drop_nlink(&vnode->vfs_inode);
			if (vnode->vfs_inode.i_nlink == 0) {
				set_bit(AFS_VNODE_DELETED, &vnode->flags);
				clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
			}
		}
		if (ret == 0 &&
		    test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
			afs_edit_dir_remove(dvnode, &dentry->d_name,
					    afs_edit_dir_for_unlink);
	}

	_leave(" = %d", ret);
	return ret;
}

/*
 * Remove sillyrename file on iput.
 */
int afs_silly_iput(struct dentry *dentry, struct inode *inode)
{
	struct afs_vnode *dvnode = AFS_FS_I(d_inode(dentry->d_parent));
	struct afs_vnode *vnode = AFS_FS_I(inode);
	struct dentry *alias;
	int ret;

	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);

	_enter("%p{%pd},%llx", dentry, dentry, vnode->fid.vnode);

	down_read(&dvnode->rmdir_lock);

	alias = d_alloc_parallel(dentry->d_parent, &dentry->d_name, &wq);
	if (IS_ERR(alias)) {
		up_read(&dvnode->rmdir_lock);
		return 0;
	}

	if (!d_in_lookup(alias)) {
		/* We raced with lookup...  See if we need to transfer the
		 * sillyrename information to the aliased dentry.
		 */
		ret = 0;
		spin_lock(&alias->d_lock);
		if (d_really_is_positive(alias) &&
		    !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
			alias->d_flags |= DCACHE_NFSFS_RENAMED;
			ret = 1;
		}
		spin_unlock(&alias->d_lock);
		up_read(&dvnode->rmdir_lock);
		dput(alias);
		return ret;
	}

	/* Stop lock-release from complaining. */
	spin_lock(&vnode->lock);
	vnode->lock_state = AFS_VNODE_LOCK_DELETED;
	trace_afs_flock_ev(vnode, NULL, afs_flock_silly_delete, 0);
	spin_unlock(&vnode->lock);

	afs_do_silly_unlink(dvnode, vnode, dentry, dvnode->silly_key);
	up_read(&dvnode->rmdir_lock);
	d_lookup_done(alias);
	dput(alias);
	return 1;
}
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