Quoting sukadev@xxxxxxxxxx (sukadev@xxxxxxxxxx): > > >From bdba42b68e2b6765615618fce7eb7d4c6f75685d Mon Sep 17 00:00:00 2001 > From: Sukadev Bhattiprolu <sukadev@xxxxxxxxxx> > Date: Tue, 9 Sep 2008 10:22:11 -0700 > Subject: [PATCH 02/10] Per-mount allocated_ptys > > To enable multiple mounts of devpts, 'allocated_ptys' must be a per-mount > variable rather than a global variable. Move 'allocated_ptys' into the > super_block's s_fs_info. > > Changelog[v2]: > Define and use DEVPTS_SB() wrapper. > > Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxx> > --- > fs/devpts/inode.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++------ > 1 files changed, 48 insertions(+), 7 deletions(-) > > diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c > index ec33833..6e63db7 100644 > --- a/fs/devpts/inode.c > +++ b/fs/devpts/inode.c > @@ -30,7 +30,6 @@ > #define PTMX_MINOR 2 > > extern int pty_limit; /* Config limit on Unix98 ptys */ > -static DEFINE_IDA(allocated_ptys); > static DEFINE_MUTEX(allocated_ptys_lock); > > static struct vfsmount *devpts_mnt; > @@ -55,6 +54,15 @@ static match_table_t tokens = { > {Opt_err, NULL} > }; > > +struct pts_fs_info { > + struct ida allocated_ptys; > +}; > + > +static inline struct pts_fs_info *DEVPTS_SB(struct super_block *sb) This is an odd name... how about DEVPTS_SBINFO or DEVPTS_SB_IDA? > +{ > + return sb->s_fs_info; > +} > + > static inline struct super_block *pts_sb_from_inode(struct inode *inode) > { > if (inode->i_sb->s_magic == DEVPTS_SUPER_MAGIC) > @@ -126,6 +134,19 @@ static const struct super_operations devpts_sops = { > .show_options = devpts_show_options, > }; > > +static void *new_pts_fs_info(void) > +{ > + struct pts_fs_info *fsi; > + > + fsi = kzalloc(sizeof(struct pts_fs_info), GFP_KERNEL); > + if (!fsi) > + return NULL; > + > + ida_init(&fsi->allocated_ptys); > + > + return fsi; > +} > + > static int > devpts_fill_super(struct super_block *s, void *data, int silent) > { > @@ -137,9 +158,13 @@ devpts_fill_super(struct super_block *s, void *data, int silent) > s->s_op = &devpts_sops; > s->s_time_gran = 1; > > + s->s_fs_info = new_pts_fs_info(); > + if (!s->s_fs_info) > + goto fail; > + > inode = new_inode(s); > if (!inode) > - goto fail; > + goto free_fsi; > inode->i_ino = 1; > inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; > inode->i_blocks = 0; > @@ -155,6 +180,9 @@ devpts_fill_super(struct super_block *s, void *data, int silent) > > printk("devpts: get root dentry failed\n"); > iput(inode); > + > +free_fsi: > + kfree(s->s_fs_info); > fail: > return -ENOMEM; > } > @@ -165,11 +193,19 @@ static int devpts_get_sb(struct file_system_type *fs_type, > return get_sb_single(fs_type, flags, data, devpts_fill_super, mnt); > } > > +static void devpts_kill_sb(struct super_block *sb) > +{ > + struct pts_fs_info *fsi = DEVPTS_SB(sb); > + don't you need to ida_destroy(fsi->allocated_ptys) ? > + kfree(fsi); > + kill_anon_super(sb); > +} > + > static struct file_system_type devpts_fs_type = { > .owner = THIS_MODULE, > .name = "devpts", > .get_sb = devpts_get_sb, > - .kill_sb = kill_anon_super, > + .kill_sb = devpts_kill_sb, > }; > > /* > @@ -179,16 +215,18 @@ static struct file_system_type devpts_fs_type = { > > int devpts_new_index(struct inode *ptmx_inode) > { > + struct super_block *sb = pts_sb_from_inode(ptmx_inode); > + struct pts_fs_info *fsi = DEVPTS_SB(sb); > int index; > int ida_ret; > > retry: > - if (!ida_pre_get(&allocated_ptys, GFP_KERNEL)) { > + if (!ida_pre_get(&fsi->allocated_ptys, GFP_KERNEL)) { > return -ENOMEM; > } > > mutex_lock(&allocated_ptys_lock); > - ida_ret = ida_get_new(&allocated_ptys, &index); > + ida_ret = ida_get_new(&fsi->allocated_ptys, &index); > if (ida_ret < 0) { > mutex_unlock(&allocated_ptys_lock); > if (ida_ret == -EAGAIN) > @@ -197,7 +235,7 @@ retry: > } > > if (index >= pty_limit) { > - ida_remove(&allocated_ptys, index); > + ida_remove(&fsi->allocated_ptys, index); > mutex_unlock(&allocated_ptys_lock); > return -EIO; > } > @@ -207,8 +245,11 @@ retry: > > void devpts_kill_index(struct inode *ptmx_inode, int idx) > { > + struct super_block *sb = pts_sb_from_inode(ptmx_inode); > + struct pts_fs_info *fsi = DEVPTS_SB(sb); > + > mutex_lock(&allocated_ptys_lock); > - ida_remove(&allocated_ptys, idx); > + ida_remove(&fsi->allocated_ptys, idx); > mutex_unlock(&allocated_ptys_lock); > } > > -- > 1.5.2.5 _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers