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 <konishi.ryusuke@lab.ntt.co.jp>
This commit is contained in:
Ryusuke Konishi 2010-01-31 19:46:40 +09:00
parent 7512487e6d
commit fe5f171bb2
2 changed files with 9 additions and 5 deletions

View file

@ -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;

View file

@ -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;