Merge branch 'xfs-stack-fixes' into for-next

3 files changed, 265 insertions, 143 deletions

diff --git a/fs/xfs/xfs_dir2.c b/fs/xfs/xfs_dir2.c
index ce16ef02997a..fda46253966a 100644
--- a/fs/xfs/xfs_dir2.c
+++ b/fs/xfs/xfs_dir2.c
@@ -180,16 +180,23 @@ xfs_dir_init(
 	xfs_inode_t	*dp,
 	xfs_inode_t	*pdp)
 {
-	xfs_da_args_t	args;
+	struct xfs_da_args *args;
 	int		error;
 
-	memset((char *)&args, 0, sizeof(args));
-	args.dp = dp;
-	args.trans = tp;
 	ASSERT(S_ISDIR(dp->i_d.di_mode));
-	if ((error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino)))
+	error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
+	if (error)
 		return error;
-	return xfs_dir2_sf_create(&args, pdp->i_ino);
+
+	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
+	if (!args)
+		return ENOMEM;
+
+	args->dp = dp;
+	args->trans = tp;
+	error = xfs_dir2_sf_create(args, pdp->i_ino);
+	kmem_free(args);
+	return error;
 }
 
 /*
@@ -205,41 +212,56 @@ xfs_dir_createname(
 	xfs_bmap_free_t		*flist,		/* bmap's freeblock list */
 	xfs_extlen_t		total)		/* bmap's total block count */
 {
-	xfs_da_args_t		args;
+	struct xfs_da_args	*args;
 	int			rval;
 	int			v;		/* type-checking value */
 
 	ASSERT(S_ISDIR(dp->i_d.di_mode));
-	if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
+	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
+	if (rval)
 		return rval;
 	XFS_STATS_INC(xs_dir_create);
 
-	memset(&args, 0, sizeof(xfs_da_args_t));
-	args.name = name->name;
-	args.namelen = name->len;
-	args.filetype = name->type;
-	args.hashval = dp->i_mount->m_dirnameops->hashname(name);
-	args.inumber = inum;
-	args.dp = dp;
-	args.firstblock = first;
-	args.flist = flist;
-	args.total = total;
-	args.whichfork = XFS_DATA_FORK;
-	args.trans = tp;
-	args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
-
-	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
-		rval = xfs_dir2_sf_addname(&args);
-	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_block_addname(&args);
-	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_leaf_addname(&args);
+	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
+	if (!args)
+		return ENOMEM;
+
+	args->name = name->name;
+	args->namelen = name->len;
+	args->filetype = name->type;
+	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
+	args->inumber = inum;
+	args->dp = dp;
+	args->firstblock = first;
+	args->flist = flist;
+	args->total = total;
+	args->whichfork = XFS_DATA_FORK;
+	args->trans = tp;
+	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
+
+	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
+		rval = xfs_dir2_sf_addname(args);
+		goto out_free;
+	}
+
+	rval = xfs_dir2_isblock(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v) {
+		rval = xfs_dir2_block_addname(args);
+		goto out_free;
+	}
+
+	rval = xfs_dir2_isleaf(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v)
+		rval = xfs_dir2_leaf_addname(args);
 	else
-		rval = xfs_dir2_node_addname(&args);
+		rval = xfs_dir2_node_addname(args);
+
+out_free:
+	kmem_free(args);
 	return rval;
 }
 
@@ -282,46 +304,66 @@ xfs_dir_lookup(
 	xfs_ino_t	*inum,		/* out: inode number */
 	struct xfs_name *ci_name)	/* out: actual name if CI match */
 {
-	xfs_da_args_t	args;
+	struct xfs_da_args *args;
 	int		rval;
 	int		v;		/* type-checking value */
 
 	ASSERT(S_ISDIR(dp->i_d.di_mode));
 	XFS_STATS_INC(xs_dir_lookup);
 
-	memset(&args, 0, sizeof(xfs_da_args_t));
-	args.name = name->name;
-	args.namelen = name->len;
-	args.filetype = name->type;
-	args.hashval = dp->i_mount->m_dirnameops->hashname(name);
-	args.dp = dp;
-	args.whichfork = XFS_DATA_FORK;
-	args.trans = tp;
-	args.op_flags = XFS_DA_OP_OKNOENT;
+	/*
+	 * We need to use KM_NOFS here so that lockdep will not throw false
+	 * positive deadlock warnings on a non-transactional lookup path. It is
+	 * safe to recurse into inode recalim in that case, but lockdep can't
+	 * easily be taught about it. Hence KM_NOFS avoids having to add more
+	 * lockdep Doing this avoids having to add a bunch of lockdep class
+	 * annotations into the reclaim path for the ilock.
+	 */
+	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
+	args->name = name->name;
+	args->namelen = name->len;
+	args->filetype = name->type;
+	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
+	args->dp = dp;
+	args->whichfork = XFS_DATA_FORK;
+	args->trans = tp;
+	args->op_flags = XFS_DA_OP_OKNOENT;
 	if (ci_name)
-		args.op_flags |= XFS_DA_OP_CILOOKUP;
+		args->op_flags |= XFS_DA_OP_CILOOKUP;
 
-	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
-		rval = xfs_dir2_sf_lookup(&args);
-	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_block_lookup(&args);
-	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_leaf_lookup(&args);
+	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
+		rval = xfs_dir2_sf_lookup(args);
+		goto out_check_rval;
+	}
+
+	rval = xfs_dir2_isblock(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v) {
+		rval = xfs_dir2_block_lookup(args);
+		goto out_check_rval;
+	}
+
+	rval = xfs_dir2_isleaf(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v)
+		rval = xfs_dir2_leaf_lookup(args);
 	else
-		rval = xfs_dir2_node_lookup(&args);
+		rval = xfs_dir2_node_lookup(args);
+
+out_check_rval:
 	if (rval == EEXIST)
 		rval = 0;
 	if (!rval) {
-		*inum = args.inumber;
+		*inum = args->inumber;
 		if (ci_name) {
-			ci_name->name = args.value;
-			ci_name->len = args.valuelen;
+			ci_name->name = args->value;
+			ci_name->len = args->valuelen;
 		}
 	}
+out_free:
+	kmem_free(args);
 	return rval;
 }
 
@@ -338,38 +380,51 @@ xfs_dir_removename(
 	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
 	xfs_extlen_t	total)		/* bmap's total block count */
 {
-	xfs_da_args_t	args;
+	struct xfs_da_args *args;
 	int		rval;
 	int		v;		/* type-checking value */
 
 	ASSERT(S_ISDIR(dp->i_d.di_mode));
 	XFS_STATS_INC(xs_dir_remove);
 
-	memset(&args, 0, sizeof(xfs_da_args_t));
-	args.name = name->name;
-	args.namelen = name->len;
-	args.filetype = name->type;
-	args.hashval = dp->i_mount->m_dirnameops->hashname(name);
-	args.inumber = ino;
-	args.dp = dp;
-	args.firstblock = first;
-	args.flist = flist;
-	args.total = total;
-	args.whichfork = XFS_DATA_FORK;
-	args.trans = tp;
-
-	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
-		rval = xfs_dir2_sf_removename(&args);
-	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_block_removename(&args);
-	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_leaf_removename(&args);
+	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
+	if (!args)
+		return ENOMEM;
+
+	args->name = name->name;
+	args->namelen = name->len;
+	args->filetype = name->type;
+	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
+	args->inumber = ino;
+	args->dp = dp;
+	args->firstblock = first;
+	args->flist = flist;
+	args->total = total;
+	args->whichfork = XFS_DATA_FORK;
+	args->trans = tp;
+
+	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
+		rval = xfs_dir2_sf_removename(args);
+		goto out_free;
+	}
+
+	rval = xfs_dir2_isblock(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v) {
+		rval = xfs_dir2_block_removename(args);
+		goto out_free;
+	}
+
+	rval = xfs_dir2_isleaf(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v)
+		rval = xfs_dir2_leaf_removename(args);
 	else
-		rval = xfs_dir2_node_removename(&args);
+		rval = xfs_dir2_node_removename(args);
+out_free:
+	kmem_free(args);
 	return rval;
 }
 
@@ -386,40 +441,54 @@ xfs_dir_replace(
 	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
 	xfs_extlen_t	total)		/* bmap's total block count */
 {
-	xfs_da_args_t	args;
+	struct xfs_da_args *args;
 	int		rval;
 	int		v;		/* type-checking value */
 
 	ASSERT(S_ISDIR(dp->i_d.di_mode));
 
-	if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
+	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
+	if (rval)
 		return rval;
 
-	memset(&args, 0, sizeof(xfs_da_args_t));
-	args.name = name->name;
-	args.namelen = name->len;
-	args.filetype = name->type;
-	args.hashval = dp->i_mount->m_dirnameops->hashname(name);
-	args.inumber = inum;
-	args.dp = dp;
-	args.firstblock = first;
-	args.flist = flist;
-	args.total = total;
-	args.whichfork = XFS_DATA_FORK;
-	args.trans = tp;
-
-	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
-		rval = xfs_dir2_sf_replace(&args);
-	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_block_replace(&args);
-	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_leaf_replace(&args);
+	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
+	if (!args)
+		return ENOMEM;
+
+	args->name = name->name;
+	args->namelen = name->len;
+	args->filetype = name->type;
+	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
+	args->inumber = inum;
+	args->dp = dp;
+	args->firstblock = first;
+	args->flist = flist;
+	args->total = total;
+	args->whichfork = XFS_DATA_FORK;
+	args->trans = tp;
+
+	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
+		rval = xfs_dir2_sf_replace(args);
+		goto out_free;
+	}
+
+	rval = xfs_dir2_isblock(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v) {
+		rval = xfs_dir2_block_replace(args);
+		goto out_free;
+	}
+
+	rval = xfs_dir2_isleaf(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v)
+		rval = xfs_dir2_leaf_replace(args);
 	else
-		rval = xfs_dir2_node_replace(&args);
+		rval = xfs_dir2_node_replace(args);
+out_free:
+	kmem_free(args);
 	return rval;
 }
 
@@ -434,7 +503,7 @@ xfs_dir_canenter(
 	struct xfs_name	*name,		/* name of entry to add */
 	uint		resblks)
 {
-	xfs_da_args_t	args;
+	struct xfs_da_args *args;
 	int		rval;
 	int		v;		/* type-checking value */
 
@@ -443,29 +512,42 @@ xfs_dir_canenter(
 
 	ASSERT(S_ISDIR(dp->i_d.di_mode));
 
-	memset(&args, 0, sizeof(xfs_da_args_t));
-	args.name = name->name;
-	args.namelen = name->len;
-	args.filetype = name->type;
-	args.hashval = dp->i_mount->m_dirnameops->hashname(name);
-	args.dp = dp;
-	args.whichfork = XFS_DATA_FORK;
-	args.trans = tp;
-	args.op_flags = XFS_DA_OP_JUSTCHECK | XFS_DA_OP_ADDNAME |
+	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
+	if (!args)
+		return ENOMEM;
+
+	args->name = name->name;
+	args->namelen = name->len;
+	args->filetype = name->type;
+	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
+	args->dp = dp;
+	args->whichfork = XFS_DATA_FORK;
+	args->trans = tp;
+	args->op_flags = XFS_DA_OP_JUSTCHECK | XFS_DA_OP_ADDNAME |
 							XFS_DA_OP_OKNOENT;
 
-	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
-		rval = xfs_dir2_sf_addname(&args);
-	else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_block_addname(&args);
-	else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
-		return rval;
-	else if (v)
-		rval = xfs_dir2_leaf_addname(&args);
+	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
+		rval = xfs_dir2_sf_addname(args);
+		goto out_free;
+	}
+
+	rval = xfs_dir2_isblock(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v) {
+		rval = xfs_dir2_block_addname(args);
+		goto out_free;
+	}
+
+	rval = xfs_dir2_isleaf(tp, dp, &v);
+	if (rval)
+		goto out_free;
+	if (v)
+		rval = xfs_dir2_leaf_addname(args);
 	else
-		rval = xfs_dir2_node_addname(&args);
+		rval = xfs_dir2_node_addname(args);
+out_free:
+	kmem_free(args);
 	return rval;
 }
 
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 9ddfb8190ca1..bb3bb658e39c 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -48,6 +48,18 @@
 #include <linux/fiemap.h>
 #include <linux/slab.h>
 
+/*
+ * Directories have different lock order w.r.t. mmap_sem compared to regular
+ * files. This is due to readdir potentially triggering page faults on a user
+ * buffer inside filldir(), and this happens with the ilock on the directory
+ * held. For regular files, the lock order is the other way around - the
+ * mmap_sem is taken during the page fault, and then we lock the ilock to do
+ * block mapping. Hence we need a different class for the directory ilock so
+ * that lockdep can tell them apart.
+ */
+static struct lock_class_key xfs_nondir_ilock_class;
+static struct lock_class_key xfs_dir_ilock_class;
+
 static int
 xfs_initxattrs(
 	struct inode		*inode,
@@ -1191,6 +1203,7 @@ xfs_setup_inode(
 	xfs_diflags_to_iflags(inode, ip);
 
 	ip->d_ops = ip->i_mount->m_nondir_inode_ops;
+	lockdep_set_class(&ip->i_lock.mr_lock, &xfs_nondir_ilock_class);
 	switch (inode->i_mode & S_IFMT) {
 	case S_IFREG:
 		inode->i_op = &xfs_inode_operations;
@@ -1198,6 +1211,7 @@ xfs_setup_inode(
 		inode->i_mapping->a_ops = &xfs_address_space_operations;
 		break;
 	case S_IFDIR:
+		lockdep_set_class(&ip->i_lock.mr_lock, &xfs_dir_ilock_class);
 		if (xfs_sb_version_hasasciici(&XFS_M(inode->i_sb)->m_sb))
 			inode->i_op = &xfs_dir_ci_inode_operations;
 		else
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index b57a8e08b3d1..7e5455391176 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -499,13 +499,6 @@ xlog_cil_push(
 	cil->xc_ctx = new_ctx;
 
 	/*
-	 * mirror the new sequence into the cil structure so that we can do
-	 * unlocked checks against the current sequence in log forces without
-	 * risking deferencing a freed context pointer.
-	 */
-	cil->xc_current_sequence = new_ctx->sequence;
-
-	/*
 	 * The switch is now done, so we can drop the context lock and move out
 	 * of a shared context. We can't just go straight to the commit record,
 	 * though - we need to synchronise with previous and future commits so
@@ -523,8 +516,15 @@ xlog_cil_push(
 	 * Hence we need to add this context to the committing context list so
 	 * that higher sequences will wait for us to write out a commit record
 	 * before they do.
+	 *
+	 * xfs_log_force_lsn requires us to mirror the new sequence into the cil
+	 * structure atomically with the addition of this sequence to the
+	 * committing list. This also ensures that we can do unlocked checks
+	 * against the current sequence in log forces without risking
+	 * deferencing a freed context pointer.
 	 */
 	spin_lock(&cil->xc_push_lock);
+	cil->xc_current_sequence = new_ctx->sequence;
 	list_add(&ctx->committing, &cil->xc_committing);
 	spin_unlock(&cil->xc_push_lock);
 	up_write(&cil->xc_ctx_lock);
@@ -662,8 +662,14 @@ xlog_cil_push_background(
 
 }
 
+/*
+ * xlog_cil_push_now() is used to trigger an immediate CIL push to the sequence
+ * number that is passed. When it returns, the work will be queued for
+ * @push_seq, but it won't be completed. The caller is expected to do any
+ * waiting for push_seq to complete if it is required.
+ */
 static void
-xlog_cil_push_foreground(
+xlog_cil_push_now(
 	struct xlog	*log,
 	xfs_lsn_t	push_seq)
 {
@@ -688,10 +694,8 @@ xlog_cil_push_foreground(
 	}
 
 	cil->xc_push_seq = push_seq;
+	queue_work(log->l_mp->m_cil_workqueue, &cil->xc_push_work);
 	spin_unlock(&cil->xc_push_lock);
-
-	/* do the push now */
-	xlog_cil_push(log);
 }
 
 bool
@@ -795,7 +799,8 @@ xlog_cil_force_lsn(
 	 * xlog_cil_push() handles racing pushes for the same sequence,
 	 * so no need to deal with it here.
 	 */
-	xlog_cil_push_foreground(log, sequence);
+restart:
+	xlog_cil_push_now(log, sequence);
 
 	/*
 	 * See if we can find a previous sequence still committing.
@@ -803,7 +808,6 @@ xlog_cil_force_lsn(
 	 * before allowing the force of push_seq to go ahead. Hence block
 	 * on commits for those as well.
 	 */
-restart:
 	spin_lock(&cil->xc_push_lock);
 	list_for_each_entry(ctx, &cil->xc_committing, committing) {
 		if (ctx->sequence > sequence)
@@ -821,6 +825,28 @@ restart:
 		/* found it! */
 		commit_lsn = ctx->commit_lsn;
 	}
+
+	/*
+	 * The call to xlog_cil_push_now() executes the push in the background.
+	 * Hence by the time we have got here it our sequence may not have been
+	 * pushed yet. This is true if the current sequence still matches the
+	 * push sequence after the above wait loop and the CIL still contains
+	 * dirty objects.
+	 *
+	 * When the push occurs, it will empty the CIL and
+	 * atomically increment the currect sequence past the push sequence and
+	 * move it into the committing list. Of course, if the CIL is clean at
+	 * the time of the push, it won't have pushed the CIL at all, so in that
+	 * case we should try the push for this sequence again from the start
+	 * just in case.
+	 */
+
+	if (sequence == cil->xc_current_sequence &&
+	    !list_empty(&cil->xc_cil)) {
+		spin_unlock(&cil->xc_push_lock);
+		goto restart;
+	}
+
 	spin_unlock(&cil->xc_push_lock);
 	return commit_lsn;
 }