From fe5f171bb272946ce5fbf843ce2f8467d0d41b9a Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Sun, 31 Jan 2010 19:46:40 +0900 Subject: [PATCH] nilfs2: fix potential hang in nilfs_error on errors=remount-ro nilfs_error() calls nilfs_detach_segment_constructor() if errors=remount-ro option is specified, and this may lead to a hang due to recursive locking of, for instance, nilfs->ns_segctor_sem and others. In this case, detaching segment constructor is not necessary because read-only flag is set to the filesystem and further writes are blocked. This fixes the potential hang issue by removing the nilfs_detach_segment_constructor() call from nilfs_error. Signed-off-by: Ryusuke Konishi --- fs/nilfs2/segment.c | 11 +++++++++-- fs/nilfs2/super.c | 3 --- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 9280b0f10792..ab439a7ef2d8 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -2875,8 +2875,15 @@ int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi) struct the_nilfs *nilfs = sbi->s_nilfs; int err; - /* Each field of nilfs_segctor is cleared through the initialization - of super-block info */ + if (NILFS_SC(sbi)) { + /* + * This happens if the filesystem was remounted + * read/write after nilfs_error degenerated it into a + * read-only mount. + */ + nilfs_detach_segment_constructor(sbi); + } + sbi->s_sc_info = nilfs_segctor_new(sbi); if (!sbi->s_sc_info) return -ENOMEM; diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 3f88401a375b..f068270f6c75 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -96,9 +96,6 @@ void nilfs_error(struct super_block *sb, const char *function, if (!(sb->s_flags & MS_RDONLY)) { struct the_nilfs *nilfs = sbi->s_nilfs; - if (!nilfs_test_opt(sbi, ERRORS_CONT)) - nilfs_detach_segment_constructor(sbi); - down_write(&nilfs->ns_sem); if (!(nilfs->ns_mount_state & NILFS_ERROR_FS)) { nilfs->ns_mount_state |= NILFS_ERROR_FS; -- 2.34.1