Messages in this thread | | | Date | Tue, 12 Dec 2006 15:36:26 -0500 | From | Peter Staubach <> | Subject | Re: [PATCH 2/3] ensure unique i_ino in filesystems without permanent |
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Jeff Layton wrote: > linux@horizon.com wrote: > >> Doh! Thanks for explaining that. Here's a respun patch with your > suggestion > >> incorporated. Seems to build correctly without stdbool.h. In fact, > I don't see > >> a stdbool.h in Linus' tree as of this morning. Are you sure that > it's needed? > > > > include/linux/types.h:36:typedef _Bool bool; > > > > It's already in there. And <linux/stddef.h> has false and true. > > > > Sorry; I write more user-level code. > > > > The'd be built-in, except that C99 didn't want to add a kewords that > > might conflict with existing code. > > Ok, that makes sense. Though I just found a bug that I missed. I > forgot to change the > EXPORT_SYMBOL in libfs.c. This should fix it: > > Signed-off-by: Jeff Layton <jlayton@redhat.com> > > --- linux-2.6/fs/debugfs/inode.c.super > +++ linux-2.6/fs/debugfs/inode.c > @@ -107,7 +107,7 @@ static int debug_fill_super(struct super > { > static struct tree_descr debug_files[] = {{""}}; > > - return simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); > + return registered_fill_super(sb, DEBUGFS_MAGIC, debug_files); > } > > static int debug_get_sb(struct file_system_type *fs_type, > --- linux-2.6/fs/fuse/control.c.super > +++ linux-2.6/fs/fuse/control.c > @@ -163,7 +163,7 @@ static int fuse_ctl_fill_super(struct su > struct fuse_conn *fc; > int err; > > - err = simple_fill_super(sb, FUSE_CTL_SUPER_MAGIC, &empty_descr); > + err = registered_fill_super(sb, FUSE_CTL_SUPER_MAGIC, &empty_descr); > if (err) > return err; > > --- linux-2.6/fs/libfs.c.super > +++ linux-2.6/fs/libfs.c > @@ -215,7 +215,7 @@ int get_sb_pseudo(struct file_system_typ > s->s_op = ops ? ops : &default_ops; > s->s_time_gran = 1; > root = new_inode(s); > - if (!root) > + if (!root || iunique_register(root, 0)) > goto Enomem; > root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR; > root->i_uid = root->i_gid = 0; > @@ -356,7 +356,8 @@ int simple_commit_write(struct file *fil > return 0; > } >
If iunique_register() fails, does not this create a memory leak because root will need to get iput()'d?
> -int simple_fill_super(struct super_block *s, int magic, struct > tree_descr *files) > +int __simple_fill_super(struct super_block *s, int magic, > + struct tree_descr *files, bool registered) > { > static struct super_operations s_ops = {.statfs = simple_statfs}; > struct inode *inode; > @@ -380,6 +381,12 @@ int simple_fill_super(struct super_block > inode->i_op = &simple_dir_inode_operations; > inode->i_fop = &simple_dir_operations; > inode->i_nlink = 2; > + /* > + * set this as high as a 32 bit val as possible to avoid collisions. > + * This is also well above the highest value that iunique_register > + * will assign to an inode > + */ > + inode->i_ino = 0xffffffff; > root = d_alloc_root(inode); > if (!root) { > iput(inode); > @@ -394,12 +401,15 @@ int simple_fill_super(struct super_block > inode = new_inode(s); > if (!inode) > goto out; > + if (!registered) > + inode->i_ino = i; > + else if (iunique_register(inode, 0)) > + goto out;
Does this not create a memory leak as well?
Thanx...
ps
> inode->i_mode = S_IFREG | files->mode; > inode->i_uid = inode->i_gid = 0; > inode->i_blocks = 0; > inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; > inode->i_fop = files->ops; > - inode->i_ino = i; > d_add(dentry, inode); > } > s->s_root = root; > @@ -618,7 +628,7 @@ EXPORT_SYMBOL(simple_dir_inode_operation > EXPORT_SYMBOL(simple_dir_operations); > EXPORT_SYMBOL(simple_empty); > EXPORT_SYMBOL(d_alloc_name); > -EXPORT_SYMBOL(simple_fill_super); > +EXPORT_SYMBOL(__simple_fill_super); > EXPORT_SYMBOL(simple_getattr); > EXPORT_SYMBOL(simple_link); > EXPORT_SYMBOL(simple_lookup); > --- linux-2.6/include/linux/fs.h.super > +++ linux-2.6/include/linux/fs.h > @@ -1879,10 +1879,35 @@ extern const struct file_operations simp > extern struct inode_operations simple_dir_inode_operations; > struct tree_descr { char *name; const struct file_operations *ops; > int mode; }; > struct dentry *d_alloc_name(struct dentry *, const char *); > -extern int simple_fill_super(struct super_block *, int, struct > tree_descr *); > +extern int __simple_fill_super(struct super_block *s, int magic, > + struct tree_descr *files, bool registered); > extern int simple_pin_fs(struct file_system_type *, struct vfsmount > **mount, int *count); > extern void simple_release_fs(struct vfsmount **mount, int *count); > > +/* > + * Fill a superblock with a standard set of fields, and add the > entries in the > + * "files" struct. Assign i_ino values to the files sequentially. > This function > + * is appropriate for filesystems that need a particular i_ino value > assigned > + * to a particular "files" entry. > + */ > +static inline int simple_fill_super(struct super_block *s, int magic, > + struct tree_descr *files) > +{ > + return __simple_fill_super(s, magic, files, false); > +} > + > +/* > + * Just like simple_fill_super, but does an iunique_register on the > inodes > + * created for "files" entries. This function is appropriate when you > don't > + * need a particular i_ino value assigned to each files entry, and > when the > + * filesystem will have other registered inodes. > + */ > +static inline int registered_fill_super(struct super_block *s, int > magic, > + struct tree_descr *files) > +{ > + return __simple_fill_super(s, magic, files, true); > +} > + > extern ssize_t simple_read_from_buffer(void __user *, size_t, loff_t > *, const void *, size_t); > > #ifdef CONFIG_MIGRATION > --- linux-2.6/security/inode.c.super > +++ linux-2.6/security/inode.c > @@ -130,7 +130,7 @@ static int fill_super(struct super_block > { > static struct tree_descr files[] = {{""}}; > > - return simple_fill_super(sb, SECURITYFS_MAGIC, files); > + return registered_fill_super(sb, SECURITYFS_MAGIC, files); > } > > static int get_sb(struct file_system_type *fs_type, > - > To unsubscribe from this list: send the line "unsubscribe > linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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