From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B08AC1FCFF3; Tue, 8 Apr 2025 12:25:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744115113; cv=none; b=bMmOMaSkXl4fusmg6aLVYkh5ZthMPRx9vL072I3hjRacATTvJN13m8Rx5hHDpv5z86G0uuJElsoCXvmiLNBiKAxVFVSQNabhRMRGn2yozRt/20PeD8Cm3WCW70KtJTvk3aVlQJBG26lQqHtPoyMT1Ve/o4aSBARAaIqNJKmVgek= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744115113; c=relaxed/simple; bh=WTFL6DNrCu9yjNCqQxbM8i75J//1Zj4yR52S5NFqpI4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=g0mpCKDIBfI5vA3tDoAtfiotaWgJTgLEnKbzAl40M2IdRxq7t74S2wx551CgwTyga83sldv+kwhzvVSUAMzxUNacX4aFO6Cz4s7ws0tace08n7MD+zUgGO+vwXZhpBYZ5IaDvl8XCxEAe+GVPTeSK1UIudjI3JH+9JOCeNRngB0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yC2z9Wr6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="yC2z9Wr6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2AC3C4CEE5; Tue, 8 Apr 2025 12:25:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744115113; bh=WTFL6DNrCu9yjNCqQxbM8i75J//1Zj4yR52S5NFqpI4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yC2z9Wr6JiRm80La0lUs5pAtIQuOXXbEVG+RpyZfvIHfsKeOjCIQw9OQoK4+Hobmz UtGtjuW/UWuEVTkhov6rqNbJxVHCU8now+o5MNKdFqDtoCsEQDz/kf3Nd/hOLtOmgv r/lVEMlzJiZNgofRpNXW34v4xkI6jLRuMMMbTaIU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Al Viro , Sasha Levin Subject: [PATCH 6.13 355/499] spufs: fix gang directory lifetimes Date: Tue, 8 Apr 2025 12:49:27 +0200 Message-ID: <20250408104900.086589554@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250408104851.256868745@linuxfoundation.org> References: <20250408104851.256868745@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro [ Upstream commit c134deabf4784e155d360744d4a6a835b9de4dd4 ] prior to "[POWERPC] spufs: Fix gang destroy leaks" we used to have a problem with gang lifetimes - creation of a gang returns opened gang directory, which normally gets removed when that gets closed, but if somebody has created a context belonging to that gang and kept it alive until the gang got closed, removal failed and we ended up with a leak. Unfortunately, it had been fixed the wrong way. Dentry of gang directory was no longer pinned, and rmdir on close was gone. One problem was that failure of open kept calling simple_rmdir() as cleanup, which meant an unbalanced dput(). Another bug was in the success case - gang creation incremented link count on root directory, but that was no longer undone when gang got destroyed. Fix consists of * reverting the commit in question * adding a counter to gang, protected by ->i_rwsem of gang directory inode. * having it set to 1 at creation time, dropped in both spufs_dir_close() and spufs_gang_close() and bumped in spufs_create_context(), provided that it's not 0. * using simple_recursive_removal() to take the gang directory out when counter reaches zero. Fixes: 877907d37da9 "[POWERPC] spufs: Fix gang destroy leaks" Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- arch/powerpc/platforms/cell/spufs/gang.c | 1 + arch/powerpc/platforms/cell/spufs/inode.c | 54 +++++++++++++++++++---- arch/powerpc/platforms/cell/spufs/spufs.h | 2 + 3 files changed, 49 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/platforms/cell/spufs/gang.c b/arch/powerpc/platforms/cell/spufs/gang.c index 827d338deaf4c..2c2999de6bfa2 100644 --- a/arch/powerpc/platforms/cell/spufs/gang.c +++ b/arch/powerpc/platforms/cell/spufs/gang.c @@ -25,6 +25,7 @@ struct spu_gang *alloc_spu_gang(void) mutex_init(&gang->aff_mutex); INIT_LIST_HEAD(&gang->list); INIT_LIST_HEAD(&gang->aff_list_head); + gang->alive = 1; out: return gang; diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c index 793c005607cf0..c566e7997f2c1 100644 --- a/arch/powerpc/platforms/cell/spufs/inode.c +++ b/arch/powerpc/platforms/cell/spufs/inode.c @@ -201,6 +201,23 @@ static int spufs_fill_dir(struct dentry *dir, return 0; } +static void unuse_gang(struct dentry *dir) +{ + struct inode *inode = dir->d_inode; + struct spu_gang *gang = SPUFS_I(inode)->i_gang; + + if (gang) { + bool dead; + + inode_lock(inode); // exclusion with spufs_create_context() + dead = !--gang->alive; + inode_unlock(inode); + + if (dead) + simple_recursive_removal(dir, NULL); + } +} + static int spufs_dir_close(struct inode *inode, struct file *file) { struct inode *parent; @@ -215,6 +232,7 @@ static int spufs_dir_close(struct inode *inode, struct file *file) inode_unlock(parent); WARN_ON(ret); + unuse_gang(dir->d_parent); return dcache_dir_close(inode, file); } @@ -407,7 +425,7 @@ spufs_create_context(struct inode *inode, struct dentry *dentry, { int ret; int affinity; - struct spu_gang *gang; + struct spu_gang *gang = SPUFS_I(inode)->i_gang; struct spu_context *neighbor; struct path path = {.mnt = mnt, .dentry = dentry}; @@ -422,11 +440,15 @@ spufs_create_context(struct inode *inode, struct dentry *dentry, if ((flags & SPU_CREATE_ISOLATE) && !isolated_loader) return -ENODEV; - gang = NULL; + if (gang) { + if (!gang->alive) + return -ENOENT; + gang->alive++; + } + neighbor = NULL; affinity = flags & (SPU_CREATE_AFFINITY_MEM | SPU_CREATE_AFFINITY_SPU); if (affinity) { - gang = SPUFS_I(inode)->i_gang; if (!gang) return -EINVAL; mutex_lock(&gang->aff_mutex); @@ -455,6 +477,8 @@ spufs_create_context(struct inode *inode, struct dentry *dentry, out_aff_unlock: if (affinity) mutex_unlock(&gang->aff_mutex); + if (ret && gang) + gang->alive--; // can't reach 0 return ret; } @@ -484,6 +508,7 @@ spufs_mkgang(struct inode *dir, struct dentry *dentry, umode_t mode) inode->i_fop = &simple_dir_operations; d_instantiate(dentry, inode); + dget(dentry); inc_nlink(dir); inc_nlink(d_inode(dentry)); return ret; @@ -494,6 +519,21 @@ spufs_mkgang(struct inode *dir, struct dentry *dentry, umode_t mode) return ret; } +static int spufs_gang_close(struct inode *inode, struct file *file) +{ + unuse_gang(file->f_path.dentry); + return dcache_dir_close(inode, file); +} + +static const struct file_operations spufs_gang_fops = { + .open = dcache_dir_open, + .release = spufs_gang_close, + .llseek = dcache_dir_lseek, + .read = generic_read_dir, + .iterate_shared = dcache_readdir, + .fsync = noop_fsync, +}; + static int spufs_gang_open(const struct path *path) { int ret; @@ -513,7 +553,7 @@ static int spufs_gang_open(const struct path *path) return PTR_ERR(filp); } - filp->f_op = &simple_dir_operations; + filp->f_op = &spufs_gang_fops; fd_install(ret, filp); return ret; } @@ -528,10 +568,8 @@ static int spufs_create_gang(struct inode *inode, ret = spufs_mkgang(inode, dentry, mode & 0777); if (!ret) { ret = spufs_gang_open(&path); - if (ret < 0) { - int err = simple_rmdir(inode, dentry); - WARN_ON(err); - } + if (ret < 0) + unuse_gang(dentry); } return ret; } diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h index 84958487f696a..d33787c57c39a 100644 --- a/arch/powerpc/platforms/cell/spufs/spufs.h +++ b/arch/powerpc/platforms/cell/spufs/spufs.h @@ -151,6 +151,8 @@ struct spu_gang { int aff_flags; struct spu *aff_ref_spu; atomic_t aff_sched_count; + + int alive; }; /* Flag bits for spu_gang aff_flags */ -- 2.39.5