diff options
| -rw-r--r-- | Documentation/filesystems/porting | 18 | ||||
| -rw-r--r-- | fs/btrfs/ioctl.c | 18 | ||||
| -rw-r--r-- | fs/configfs/inode.c | 2 | ||||
| -rw-r--r-- | fs/dcache.c | 9 | ||||
| -rw-r--r-- | fs/gfs2/ops_fstype.c | 2 | ||||
| -rw-r--r-- | fs/inode.c | 12 | ||||
| -rw-r--r-- | fs/namei.c | 4 | ||||
| -rw-r--r-- | fs/ocfs2/inode.c | 2 | ||||
| -rw-r--r-- | fs/overlayfs/readdir.c | 4 | ||||
| -rw-r--r-- | fs/readdir.c | 7 | ||||
| -rw-r--r-- | include/linux/fs.h | 27 |
11 files changed, 73 insertions, 32 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 8810e23..1567a53 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -539,3 +539,21 @@ in your dentry operations instead. it's a symlink. Checking ->i_mode is really needed now. In-tree we had to fix shmem_destroy_callback() that used to take that kind of shortcut; watch out, since that shortcut is no longer valid. +-- +[mandatory] + ->i_mutex is replaced with ->i_rwsem now. inode_lock() et.al. work as + they used to - they just take it exclusive. However, ->lookup() may be + called with parent locked shared. Its instances must not + * use d_instantiate) and d_rehash() separately - use d_add() or + d_splice_alias() instead. + * use d_rehash() alone - call d_add(new_dentry, NULL) instead. + * in the unlikely case when (read-only) access to filesystem + data structures needs exclusion for some reason, arrange it + yourself. None of the in-tree filesystems needed that. + * rely on ->d_parent and ->d_name not changing after dentry has + been fed to d_add() or d_splice_alias(). Again, none of the + in-tree instances relied upon that. + We are guaranteed that lookups of the same name in the same directory + will not happen in parallel ("same" in the sense of your ->d_compare()). + Lookups on different names in the same directory can and do happen in + parallel now. diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 5a23806..0b8ba71 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -837,9 +837,11 @@ static noinline int btrfs_mksubvol(struct path *parent, struct dentry *dentry; int error; - error = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT); - if (error == -EINTR) - return error; + inode_lock_nested(dir, I_MUTEX_PARENT); + // XXX: should've been + // mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT); + // if (error == -EINTR) + // return error; dentry = lookup_one_len(name, parent->dentry, namelen); error = PTR_ERR(dentry); @@ -2366,9 +2368,11 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file, goto out; - err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT); - if (err == -EINTR) - goto out_drop_write; + inode_lock_nested(dir, I_MUTEX_PARENT); + // XXX: should've been + // err = mutex_lock_killable_nested(&dir->i_mutex, I_MUTEX_PARENT); + // if (err == -EINTR) + // goto out_drop_write; dentry = lookup_one_len(vol_args->name, parent, namelen); if (IS_ERR(dentry)) { err = PTR_ERR(dentry); @@ -2558,7 +2562,7 @@ out_dput: dput(dentry); out_unlock_dir: inode_unlock(dir); -out_drop_write: +//out_drop_write: mnt_drop_write_file(file); out: kfree(vol_args); diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c index 03d124a..0387968 100644 --- a/fs/configfs/inode.c +++ b/fs/configfs/inode.c @@ -156,7 +156,7 @@ static void configfs_set_inode_lock_class(struct configfs_dirent *sd, if (depth > 0) { if (depth <= ARRAY_SIZE(default_group_class)) { - lockdep_set_class(&inode->i_mutex, + lockdep_set_class(&inode->i_rwsem, &default_group_class[depth - 1]); } else { /* diff --git a/fs/dcache.c b/fs/dcache.c index 59fcffc..e49ba7d 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2932,7 +2932,8 @@ struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2) static int __d_unalias(struct inode *inode, struct dentry *dentry, struct dentry *alias) { - struct mutex *m1 = NULL, *m2 = NULL; + struct mutex *m1 = NULL; + struct rw_semaphore *m2 = NULL; int ret = -ESTALE; /* If alias and dentry share a parent, then no extra locks required */ @@ -2943,15 +2944,15 @@ static int __d_unalias(struct inode *inode, if (!mutex_trylock(&dentry->d_sb->s_vfs_rename_mutex)) goto out_err; m1 = &dentry->d_sb->s_vfs_rename_mutex; - if (!inode_trylock(alias->d_parent->d_inode)) + if (!inode_trylock_shared(alias->d_parent->d_inode)) goto out_err; - m2 = &alias->d_parent->d_inode->i_mutex; + m2 = &alias->d_parent->d_inode->i_rwsem; out_unalias: __d_move(alias, dentry, false); ret = 0; out_err: if (m2) - mutex_unlock(m2); + up_read(m2); if (m1) mutex_unlock(m1); return ret; diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index c09c63d..4546360 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -824,7 +824,7 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo) * i_mutex on quota files is special. Since this inode is hidden system * file, we are safe to define locking ourselves. */ - lockdep_set_class(&sdp->sd_quota_inode->i_mutex, + lockdep_set_class(&sdp->sd_quota_inode->i_rwsem, &gfs2_quota_imutex_key); error = gfs2_rindex_update(sdp); @@ -166,8 +166,8 @@ int inode_init_always(struct super_block *sb, struct inode *inode) spin_lock_init(&inode->i_lock); lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key); - mutex_init(&inode->i_mutex); - lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key); + init_rwsem(&inode->i_rwsem); + lockdep_set_class(&inode->i_rwsem, &sb->s_type->i_mutex_key); atomic_set(&inode->i_dio_count, 0); @@ -925,13 +925,13 @@ void lockdep_annotate_inode_mutex_key(struct inode *inode) struct file_system_type *type = inode->i_sb->s_type; /* Set new key only if filesystem hasn't already changed it */ - if (lockdep_match_class(&inode->i_mutex, &type->i_mutex_key)) { + if (lockdep_match_class(&inode->i_rwsem, &type->i_mutex_key)) { /* * ensure nobody is actually holding i_mutex */ - mutex_destroy(&inode->i_mutex); - mutex_init(&inode->i_mutex); - lockdep_set_class(&inode->i_mutex, + // mutex_destroy(&inode->i_mutex); + init_rwsem(&inode->i_rwsem); + lockdep_set_class(&inode->i_rwsem, &type->i_mutex_dir_key); } } @@ -1607,7 +1607,7 @@ static struct dentry *lookup_slow(const struct qstr *name, struct inode *inode = dir->d_inode; DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); - inode_lock(inode); + inode_lock_shared(inode); /* Don't go there if it's already dead */ if (unlikely(IS_DEADDIR(inode))) goto out; @@ -1638,7 +1638,7 @@ again: } } out: - inode_unlock(inode); + inode_unlock_shared(inode); return dentry; } diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index 12f4a9e..0748777 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -262,7 +262,7 @@ static int ocfs2_init_locked_inode(struct inode *inode, void *opaque) inode->i_ino = args->fi_ino; OCFS2_I(inode)->ip_blkno = args->fi_blkno; if (args->fi_sysfile_type != 0) - lockdep_set_class(&inode->i_mutex, + lockdep_set_class(&inode->i_rwsem, &ocfs2_sysfile_lock_key[args->fi_sysfile_type]); if (args->fi_sysfile_type == USER_QUOTA_SYSTEM_INODE || args->fi_sysfile_type == GROUP_QUOTA_SYSTEM_INODE || diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 6ec1e43..da186ee 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -218,7 +218,9 @@ static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd) cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE); old_cred = override_creds(override_cred); - err = mutex_lock_killable(&dir->d_inode->i_mutex); + inode_lock(dir->d_inode); + err = 0; + // XXX: err = mutex_lock_killable(&dir->d_inode->i_mutex); if (!err) { while (rdd->first_maybe_whiteout) { p = rdd->first_maybe_whiteout; diff --git a/fs/readdir.c b/fs/readdir.c index e69ef3b..bf583e8 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -32,9 +32,10 @@ int iterate_dir(struct file *file, struct dir_context *ctx) if (res) goto out; - res = mutex_lock_killable(&inode->i_mutex); - if (res) - goto out; + inode_lock(inode); + // res = mutex_lock_killable(&inode->i_mutex); + // if (res) + // goto out; res = -ENOENT; if (!IS_DEADDIR(inode)) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 00cecc5..3018f31 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -647,7 +647,7 @@ struct inode { /* Misc */ unsigned long i_state; - struct mutex i_mutex; + struct rw_semaphore i_rwsem; unsigned long dirtied_when; /* jiffies of first dirtying */ unsigned long dirtied_time_when; @@ -734,27 +734,42 @@ enum inode_i_mutex_lock_class static inline void inode_lock(struct inode *inode) { - mutex_lock(&inode->i_mutex); + down_write(&inode->i_rwsem); } static inline void inode_unlock(struct inode *inode) { - mutex_unlock(&inode->i_mutex); + up_write(&inode->i_rwsem); +} + +static inline void inode_lock_shared(struct inode *inode) +{ + down_read(&inode->i_rwsem); +} + +static inline void inode_unlock_shared(struct inode *inode) +{ + up_read(&inode->i_rwsem); } static inline int inode_trylock(struct inode *inode) { - return mutex_trylock(&inode->i_mutex); + return down_write_trylock(&inode->i_rwsem); +} + +static inline int inode_trylock_shared(struct inode *inode) +{ + return down_read_trylock(&inode->i_rwsem); } static inline int inode_is_locked(struct inode *inode) { - return mutex_is_locked(&inode->i_mutex); + return rwsem_is_locked(&inode->i_rwsem); } static inline void inode_lock_nested(struct inode *inode, unsigned subclass) { - mutex_lock_nested(&inode->i_mutex, subclass); + down_write_nested(&inode->i_rwsem, subclass); } void lock_two_nondirectories(struct inode *, struct inode*); |
