diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2011-06-17 13:33:20 -0700 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2012-11-20 04:19:19 -0800 |
| commit | 33d6dce607573b5fd7a43168e0d91221b3ca532b (patch) | |
| tree | c7743ed6aab1fe2026f20e6a1ddf708a16aa1c84 | |
| parent | 4f326c0064b20b78b8041f4d2f6fe188a1129f18 (diff) | |
proc: Generalize proc inode allocation
Generalize the proc inode allocation so that it can be
used without having to having to create a proc_dir_entry.
This will allow namespace file descriptors to remain light
weight entitities but still have the same inode number
when the backing namespace is the same.
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| -rw-r--r-- | fs/proc/generic.c | 26 | ||||
| -rw-r--r-- | include/linux/proc_fs.h | 10 |
2 files changed, 23 insertions, 13 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 0d80cef4cfb9..7b3ae3cc0ef9 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -350,14 +350,14 @@ static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */ * Return an inode number between PROC_DYNAMIC_FIRST and * 0xffffffff, or zero on failure. */ -static unsigned int get_inode_number(void) +int proc_alloc_inum(unsigned int *inum) { unsigned int i; int error; retry: - if (ida_pre_get(&proc_inum_ida, GFP_KERNEL) == 0) - return 0; + if (!ida_pre_get(&proc_inum_ida, GFP_KERNEL)) + return -ENOMEM; spin_lock(&proc_inum_lock); error = ida_get_new(&proc_inum_ida, &i); @@ -365,18 +365,19 @@ retry: if (error == -EAGAIN) goto retry; else if (error) - return 0; + return error; if (i > UINT_MAX - PROC_DYNAMIC_FIRST) { spin_lock(&proc_inum_lock); ida_remove(&proc_inum_ida, i); spin_unlock(&proc_inum_lock); - return 0; + return -ENOSPC; } - return PROC_DYNAMIC_FIRST + i; + *inum = PROC_DYNAMIC_FIRST + i; + return 0; } -static void release_inode_number(unsigned int inum) +void proc_free_inum(unsigned int inum) { spin_lock(&proc_inum_lock); ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST); @@ -554,13 +555,12 @@ static const struct inode_operations proc_dir_inode_operations = { static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp) { - unsigned int i; struct proc_dir_entry *tmp; + int ret; - i = get_inode_number(); - if (i == 0) - return -EAGAIN; - dp->low_ino = i; + ret = proc_alloc_inum(&dp->low_ino); + if (ret) + return ret; if (S_ISDIR(dp->mode)) { if (dp->proc_iops == NULL) { @@ -764,7 +764,7 @@ EXPORT_SYMBOL(proc_create_data); static void free_proc_entry(struct proc_dir_entry *de) { - release_inode_number(de->low_ino); + proc_free_inum(de->low_ino); if (S_ISLNK(de->mode)) kfree(de->data); diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 31447819bc55..bf1d000fbba6 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -176,6 +176,8 @@ extern struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name, extern struct file *proc_ns_fget(int fd); extern bool proc_ns_inode(struct inode *inode); +extern int proc_alloc_inum(unsigned int *pino); +extern void proc_free_inum(unsigned int inum); #else #define proc_net_fops_create(net, name, mode, fops) ({ (void)(mode), NULL; }) @@ -235,6 +237,14 @@ static inline bool proc_ns_inode(struct inode *inode) return false; } +static inline int proc_alloc_inum(unsigned int *inum) +{ + *inum = 1; + return 0; +} +static inline void proc_free_inum(unsigned int inum) +{ +} #endif /* CONFIG_PROC_FS */ #if !defined(CONFIG_PROC_KCORE) |