Serge E. Hallyn [EMAIL PROTECTED] wrote:
| Quoting [EMAIL PROTECTED] ([EMAIL PROTECTED]):
| >
| > >From bdba42b68e2b6765615618fce7eb7d4c6f75685d Mon Sep 17 00:00:00 2001
| > From: Sukadev Bhattiprolu <[EMAIL PROTECTED]>
| > 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 <[EMAIL PROTECTED]>
| > ---
| > 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?
I was just following established tradition :-)
EXT4_SB(), EXT3_SB(), EXT2_SB(), REISERFS_SB(), NFS_SB()
I don't mind DEVPTS_SBINFO(), but since this will soon have more than
just an ida, DEVPTS_SB_IDA() may not work.
|
| > +{
| > + 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) ?
I had it before, but since all ptys must be destroyed, and ida_remove()
frees the pages as necessary and ida_init() does not alloc memory, I had
commented it out and later removed it. Let me check again.
|
| > + 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
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