diff options
Diffstat (limited to 'fs/seq_file.c')
| -rw-r--r-- | fs/seq_file.c | 716 |
1 files changed, 567 insertions, 149 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c index 3f54dbd6c49..3857b720cb1 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -6,13 +6,42 @@ */ #include <linux/fs.h> -#include <linux/module.h> +#include <linux/export.h> #include <linux/seq_file.h> +#include <linux/vmalloc.h> #include <linux/slab.h> +#include <linux/cred.h> +#include <linux/mm.h> #include <asm/uaccess.h> #include <asm/page.h> + +/* + * seq_files have a buffer which can may overflow. When this happens a larger + * buffer is reallocated and all the data will be printed again. + * The overflow state is true when m->count == m->size. + */ +static bool seq_overflow(struct seq_file *m) +{ + return m->count == m->size; +} + +static void seq_set_overflow(struct seq_file *m) +{ + m->count = m->size; +} + +static void *seq_buf_alloc(unsigned long size) +{ + void *buf; + + buf = kmalloc(size, GFP_KERNEL | __GFP_NOWARN); + if (!buf && size > PAGE_SIZE) + buf = vmalloc(size); + return buf; +} + /** * seq_open - initialize sequential file * @file: file we initialize @@ -40,6 +69,9 @@ int seq_open(struct file *file, const struct seq_operations *op) memset(p, 0, sizeof(*p)); mutex_init(&p->lock); p->op = op; +#ifdef CONFIG_USER_NS + p->user_ns = file->f_cred->user_ns; +#endif /* * Wrappers around seq_open(e.g. swaps_open) need to be @@ -48,12 +80,79 @@ int seq_open(struct file *file, const struct seq_operations *op) */ file->f_version = 0; - /* SEQ files support lseek, but not pread/pwrite */ - file->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE); + /* + * seq_files support lseek() and pread(). They do not implement + * write() at all, but we clear FMODE_PWRITE here for historical + * reasons. + * + * If a client of seq_files a) implements file.write() and b) wishes to + * support pwrite() then that client will need to implement its own + * file.open() which calls seq_open() and then sets FMODE_PWRITE. + */ + file->f_mode &= ~FMODE_PWRITE; return 0; } EXPORT_SYMBOL(seq_open); +static int traverse(struct seq_file *m, loff_t offset) +{ + loff_t pos = 0, index; + int error = 0; + void *p; + + m->version = 0; + index = 0; + m->count = m->from = 0; + if (!offset) { + m->index = index; + return 0; + } + if (!m->buf) { + m->buf = seq_buf_alloc(m->size = PAGE_SIZE); + if (!m->buf) + return -ENOMEM; + } + p = m->op->start(m, &index); + while (p) { + error = PTR_ERR(p); + if (IS_ERR(p)) + break; + error = m->op->show(m, p); + if (error < 0) + break; + if (unlikely(error)) { + error = 0; + m->count = 0; + } + if (seq_overflow(m)) + goto Eoverflow; + if (pos + m->count > offset) { + m->from = offset - pos; + m->count -= m->from; + m->index = index; + break; + } + pos += m->count; + m->count = 0; + if (pos == offset) { + index++; + m->index = index; + break; + } + p = m->op->next(m, p, &index); + } + m->op->stop(m, p); + m->index = index; + return error; + +Eoverflow: + m->op->stop(m, p); + kvfree(m->buf); + m->count = 0; + m->buf = seq_buf_alloc(m->size <<= 1); + return !m->buf ? -ENOMEM : -EAGAIN; +} + /** * seq_read - ->read() method for sequential files. * @file: the file to read from @@ -65,7 +164,7 @@ EXPORT_SYMBOL(seq_open); */ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) { - struct seq_file *m = (struct seq_file *)file->private_data; + struct seq_file *m = file->private_data; size_t copied = 0; loff_t pos; size_t n; @@ -73,6 +172,7 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) int err = 0; mutex_lock(&m->lock); + /* * seq_file->op->..m_start/m_stop/m_next may do special actions * or optimisations based on the file->f_version, so we want to @@ -85,9 +185,26 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) * need of passing another argument to all the seq_file methods. */ m->version = file->f_version; + + /* Don't assume *ppos is where we left it */ + if (unlikely(*ppos != m->read_pos)) { + while ((err = traverse(m, *ppos)) == -EAGAIN) + ; + if (err) { + /* With prejudice... */ + m->read_pos = 0; + m->version = 0; + m->index = 0; + m->count = 0; + goto Done; + } else { + m->read_pos = *ppos; + } + } + /* grab buffer if we didn't have one */ if (!m->buf) { - m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL); + m->buf = seq_buf_alloc(m->size = PAGE_SIZE); if (!m->buf) goto Enomem; } @@ -108,9 +225,9 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) goto Done; } /* we need at least one record in buffer */ + pos = m->index; + p = m->op->start(m, &pos); while (1) { - pos = m->index; - p = m->op->start(m, &pos); err = PTR_ERR(p); if (!p || IS_ERR(p)) break; @@ -119,15 +236,22 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) break; if (unlikely(err)) m->count = 0; + if (unlikely(!m->count)) { + p = m->op->next(m, p, &pos); + m->index = pos; + continue; + } if (m->count < m->size) goto Fill; m->op->stop(m, p); - kfree(m->buf); - m->buf = kmalloc(m->size <<= 1, GFP_KERNEL); + kvfree(m->buf); + m->count = 0; + m->buf = seq_buf_alloc(m->size <<= 1); if (!m->buf) goto Enomem; - m->count = 0; m->version = 0; + pos = m->index; + p = m->op->start(m, &pos); } m->op->stop(m, p); m->count = 0; @@ -143,7 +267,7 @@ Fill: break; } err = m->op->show(m, p); - if (m->count == m->size || err) { + if (seq_overflow(m) || err) { m->count = offs; if (likely(err <= 0)) break; @@ -165,8 +289,10 @@ Fill: Done: if (!copied) copied = err; - else + else { *ppos += copied; + m->read_pos += copied; + } file->f_version = m->version; mutex_unlock(&m->lock); return copied; @@ -179,98 +305,45 @@ Efault: } EXPORT_SYMBOL(seq_read); -static int traverse(struct seq_file *m, loff_t offset) -{ - loff_t pos = 0, index; - int error = 0; - void *p; - - m->version = 0; - index = 0; - m->count = m->from = 0; - if (!offset) { - m->index = index; - return 0; - } - if (!m->buf) { - m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL); - if (!m->buf) - return -ENOMEM; - } - p = m->op->start(m, &index); - while (p) { - error = PTR_ERR(p); - if (IS_ERR(p)) - break; - error = m->op->show(m, p); - if (error < 0) - break; - if (unlikely(error)) { - error = 0; - m->count = 0; - } - if (m->count == m->size) - goto Eoverflow; - if (pos + m->count > offset) { - m->from = offset - pos; - m->count -= m->from; - m->index = index; - break; - } - pos += m->count; - m->count = 0; - if (pos == offset) { - index++; - m->index = index; - break; - } - p = m->op->next(m, p, &index); - } - m->op->stop(m, p); - return error; - -Eoverflow: - m->op->stop(m, p); - kfree(m->buf); - m->buf = kmalloc(m->size <<= 1, GFP_KERNEL); - return !m->buf ? -ENOMEM : -EAGAIN; -} - /** * seq_lseek - ->llseek() method for sequential files. * @file: the file in question * @offset: new position - * @origin: 0 for absolute, 1 for relative position + * @whence: 0 for absolute, 1 for relative position * * Ready-made ->f_op->llseek() */ -loff_t seq_lseek(struct file *file, loff_t offset, int origin) +loff_t seq_lseek(struct file *file, loff_t offset, int whence) { - struct seq_file *m = (struct seq_file *)file->private_data; + struct seq_file *m = file->private_data; loff_t retval = -EINVAL; mutex_lock(&m->lock); m->version = file->f_version; - switch (origin) { - case 1: - offset += file->f_pos; - case 0: - if (offset < 0) - break; - retval = offset; - if (offset != file->f_pos) { - while ((retval=traverse(m, offset)) == -EAGAIN) - ; - if (retval) { - /* with extreme prejudice... */ - file->f_pos = 0; - m->version = 0; - m->index = 0; - m->count = 0; - } else { - retval = file->f_pos = offset; - } + switch (whence) { + case SEEK_CUR: + offset += file->f_pos; + case SEEK_SET: + if (offset < 0) + break; + retval = offset; + if (offset != m->read_pos) { + while ((retval = traverse(m, offset)) == -EAGAIN) + ; + if (retval) { + /* with extreme prejudice... */ + file->f_pos = 0; + m->read_pos = 0; + m->version = 0; + m->index = 0; + m->count = 0; + } else { + m->read_pos = offset; + retval = file->f_pos = offset; } + } else { + file->f_pos = offset; + } } file->f_version = m->version; mutex_unlock(&m->lock); @@ -281,15 +354,15 @@ EXPORT_SYMBOL(seq_lseek); /** * seq_release - free the structures associated with sequential file. * @file: file in question - * @inode: file->f_path.dentry->d_inode + * @inode: its inode * * Frees the structures associated with sequential file; can be used * as ->f_op->release() if you don't have private data to destroy. */ int seq_release(struct inode *inode, struct file *file) { - struct seq_file *m = (struct seq_file *)file->private_data; - kfree(m->buf); + struct seq_file *m = file->private_data; + kvfree(m->buf); kfree(m); return 0; } @@ -323,7 +396,7 @@ int seq_escape(struct seq_file *m, const char *s, const char *esc) *p++ = '0' + (c & 07); continue; } - m->count = m->size; + seq_set_overflow(m); return -1; } m->count = p - m->buf; @@ -331,26 +404,47 @@ int seq_escape(struct seq_file *m, const char *s, const char *esc) } EXPORT_SYMBOL(seq_escape); -int seq_printf(struct seq_file *m, const char *f, ...) +int seq_vprintf(struct seq_file *m, const char *f, va_list args) { - va_list args; int len; if (m->count < m->size) { - va_start(args, f); len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); - va_end(args); if (m->count + len < m->size) { m->count += len; return 0; } } - m->count = m->size; + seq_set_overflow(m); return -1; } +EXPORT_SYMBOL(seq_vprintf); + +int seq_printf(struct seq_file *m, const char *f, ...) +{ + int ret; + va_list args; + + va_start(args, f); + ret = seq_vprintf(m, f, args); + va_end(args); + + return ret; +} EXPORT_SYMBOL(seq_printf); -static char *mangle_path(char *s, char *p, char *esc) +/** + * mangle_path - mangle and copy path to buffer beginning + * @s: buffer start + * @p: beginning of path in above buffer + * @esc: set of characters that need escaping + * + * Copy the path from @p to @s, replacing each occurrence of character from + * @esc with usual octal escape. + * Returns pointer past last written character in @s, or NULL in case of + * failure. + */ +char *mangle_path(char *s, const char *p, const char *esc) { while (s <= p) { char c = *p++; @@ -369,79 +463,120 @@ static char *mangle_path(char *s, char *p, char *esc) } return NULL; } +EXPORT_SYMBOL(mangle_path); -/* - * return the absolute path of 'dentry' residing in mount 'mnt'. +/** + * seq_path - seq_file interface to print a pathname + * @m: the seq_file handle + * @path: the struct path to print + * @esc: set of characters to escape in the output + * + * return the absolute path of 'path', as represented by the + * dentry / mnt pair in the path parameter. */ -int seq_path(struct seq_file *m, struct path *path, char *esc) +int seq_path(struct seq_file *m, const struct path *path, const char *esc) { - if (m->count < m->size) { - char *s = m->buf + m->count; - char *p = d_path(path, s, m->size - m->count); + char *buf; + size_t size = seq_get_buf(m, &buf); + int res = -1; + + if (size) { + char *p = d_path(path, buf, size); if (!IS_ERR(p)) { - s = mangle_path(s, p, esc); - if (s) { - p = m->buf + m->count; - m->count = s - m->buf; - return s - p; - } + char *end = mangle_path(buf, p, esc); + if (end) + res = end - buf; } } - m->count = m->size; - return -1; + seq_commit(m, res); + + return res; } EXPORT_SYMBOL(seq_path); /* * Same as seq_path, but relative to supplied root. - * - * root may be changed, see __d_path(). */ -int seq_path_root(struct seq_file *m, struct path *path, struct path *root, - char *esc) +int seq_path_root(struct seq_file *m, const struct path *path, + const struct path *root, const char *esc) { - int err = -ENAMETOOLONG; - if (m->count < m->size) { - char *s = m->buf + m->count; + char *buf; + size_t size = seq_get_buf(m, &buf); + int res = -ENAMETOOLONG; + + if (size) { char *p; - spin_lock(&dcache_lock); - p = __d_path(path, root, s, m->size - m->count); - spin_unlock(&dcache_lock); - err = PTR_ERR(p); + p = __d_path(path, root, buf, size); + if (!p) + return SEQ_SKIP; + res = PTR_ERR(p); if (!IS_ERR(p)) { - s = mangle_path(s, p, esc); - if (s) { - p = m->buf + m->count; - m->count = s - m->buf; - return 0; - } + char *end = mangle_path(buf, p, esc); + if (end) + res = end - buf; + else + res = -ENAMETOOLONG; } } - m->count = m->size; - return err; + seq_commit(m, res); + + return res < 0 && res != -ENAMETOOLONG ? res : 0; } /* * returns the path of the 'dentry' from the root of its filesystem. */ -int seq_dentry(struct seq_file *m, struct dentry *dentry, char *esc) +int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) { - if (m->count < m->size) { - char *s = m->buf + m->count; - char *p = dentry_path(dentry, s, m->size - m->count); + char *buf; + size_t size = seq_get_buf(m, &buf); + int res = -1; + + if (size) { + char *p = dentry_path(dentry, buf, size); if (!IS_ERR(p)) { - s = mangle_path(s, p, esc); - if (s) { - p = m->buf + m->count; - m->count = s - m->buf; - return s - p; - } + char *end = mangle_path(buf, p, esc); + if (end) + res = end - buf; } } - m->count = m->size; + seq_commit(m, res); + + return res; +} + +int seq_bitmap(struct seq_file *m, const unsigned long *bits, + unsigned int nr_bits) +{ + if (m->count < m->size) { + int len = bitmap_scnprintf(m->buf + m->count, + m->size - m->count, bits, nr_bits); + if (m->count + len < m->size) { + m->count += len; + return 0; + } + } + seq_set_overflow(m); + return -1; +} +EXPORT_SYMBOL(seq_bitmap); + +int seq_bitmap_list(struct seq_file *m, const unsigned long *bits, + unsigned int nr_bits) +{ + if (m->count < m->size) { + int len = bitmap_scnlistprintf(m->buf + m->count, + m->size - m->count, bits, nr_bits); + if (m->count + len < m->size) { + m->count += len; + return 0; + } + } + seq_set_overflow(m); return -1; } +EXPORT_SYMBOL(seq_bitmap_list); static void *single_start(struct seq_file *p, loff_t *pos) { @@ -479,6 +614,24 @@ int single_open(struct file *file, int (*show)(struct seq_file *, void *), } EXPORT_SYMBOL(single_open); +int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), + void *data, size_t size) +{ + char *buf = seq_buf_alloc(size); + int ret; + if (!buf) + return -ENOMEM; + ret = single_open(file, show, data); + if (ret) { + kvfree(buf); + return ret; + } + ((struct seq_file *)file->private_data)->buf = buf; + ((struct seq_file *)file->private_data)->size = size; + return 0; +} +EXPORT_SYMBOL(single_open_size); + int single_release(struct inode *inode, struct file *file) { const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; @@ -549,11 +702,98 @@ int seq_puts(struct seq_file *m, const char *s) m->count += len; return 0; } - m->count = m->size; + seq_set_overflow(m); return -1; } EXPORT_SYMBOL(seq_puts); +/* + * A helper routine for putting decimal numbers without rich format of printf(). + * only 'unsigned long long' is supported. + * This routine will put one byte delimiter + number into seq_file. + * This routine is very quick when you show lots of numbers. + * In usual cases, it will be better to use seq_printf(). It's easier to read. + */ +int seq_put_decimal_ull(struct seq_file *m, char delimiter, + unsigned long long num) +{ + int len; + + if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ + goto overflow; + + if (delimiter) + m->buf[m->count++] = delimiter; + + if (num < 10) { + m->buf[m->count++] = num + '0'; + return 0; + } + + len = num_to_str(m->buf + m->count, m->size - m->count, num); + if (!len) + goto overflow; + m->count += len; + return 0; +overflow: + seq_set_overflow(m); + return -1; +} +EXPORT_SYMBOL(seq_put_decimal_ull); + +int seq_put_decimal_ll(struct seq_file *m, char delimiter, + long long num) +{ + if (num < 0) { + if (m->count + 3 >= m->size) { + seq_set_overflow(m); + return -1; + } + if (delimiter) + m->buf[m->count++] = delimiter; + num = -num; + delimiter = '-'; + } + return seq_put_decimal_ull(m, delimiter, num); + +} +EXPORT_SYMBOL(seq_put_decimal_ll); + +/** + * seq_write - write arbitrary data to buffer + * @seq: seq_file identifying the buffer to which data should be written + * @data: data address + * @len: number of bytes + * + * Return 0 on success, non-zero otherwise. + */ +int seq_write(struct seq_file *seq, const void *data, size_t len) +{ + if (seq->count + len < seq->size) { + memcpy(seq->buf + seq->count, data, len); + seq->count += len; + return 0; + } + seq_set_overflow(seq); + return -1; +} +EXPORT_SYMBOL(seq_write); + +/** + * seq_pad - write padding spaces to buffer + * @m: seq_file identifying the buffer to which data should be written + * @c: the byte to append after padding if non-zero + */ +void seq_pad(struct seq_file *m, char c) +{ + int size = m->pad_until - m->count; + if (size > 0) + seq_printf(m, "%*s", size, ""); + if (c) + seq_putc(m, c); +} +EXPORT_SYMBOL(seq_pad); + struct list_head *seq_list_start(struct list_head *head, loff_t pos) { struct list_head *lh; @@ -564,7 +804,6 @@ struct list_head *seq_list_start(struct list_head *head, loff_t pos) return NULL; } - EXPORT_SYMBOL(seq_list_start); struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) @@ -574,7 +813,6 @@ struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) return seq_list_start(head, pos - 1); } - EXPORT_SYMBOL(seq_list_start_head); struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) @@ -585,5 +823,185 @@ struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) ++*ppos; return lh == head ? NULL : lh; } - EXPORT_SYMBOL(seq_list_next); + +/** + * seq_hlist_start - start an iteration of a hlist + * @head: the head of the hlist + * @pos: the start position of the sequence + * + * Called at seq_file->op->start(). + */ +struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) +{ + struct hlist_node *node; + + hlist_for_each(node, head) + if (pos-- == 0) + return node; + return NULL; +} +EXPORT_SYMBOL(seq_hlist_start); + +/** + * seq_hlist_start_head - start an iteration of a hlist + * @head: the head of the hlist + * @pos: the start position of the sequence + * + * Called at seq_file->op->start(). Call this function if you want to + * print a header at the top of the output. + */ +struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) +{ + if (!pos) + return SEQ_START_TOKEN; + + return seq_hlist_start(head, pos - 1); +} +EXPORT_SYMBOL(seq_hlist_start_head); + +/** + * seq_hlist_next - move to the next position of the hlist + * @v: the current iterator + * @head: the head of the hlist + * @ppos: the current position + * + * Called at seq_file->op->next(). + */ +struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, + loff_t *ppos) +{ + struct hlist_node *node = v; + + ++*ppos; + if (v == SEQ_START_TOKEN) + return head->first; + else + return node->next; +} +EXPORT_SYMBOL(seq_hlist_next); + +/** + * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU + * @head: the head of the hlist + * @pos: the start position of the sequence + * + * Called at seq_file->op->start(). + * + * This list-traversal primitive may safely run concurrently with + * the _rcu list-mutation primitives such as hlist_add_head_rcu() + * as long as the traversal is guarded by rcu_read_lock(). + */ +struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, + loff_t pos) +{ + struct hlist_node *node; + + __hlist_for_each_rcu(node, head) + if (pos-- == 0) + return node; + return NULL; +} +EXPORT_SYMBOL(seq_hlist_start_rcu); + +/** + * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU + * @head: the head of the hlist + * @pos: the start position of the sequence + * + * Called at seq_file->op->start(). Call this function if you want to + * print a header at the top of the output. + * + * This list-traversal primitive may safely run concurrently with + * the _rcu list-mutation primitives such as hlist_add_head_rcu() + * as long as the traversal is guarded by rcu_read_lock(). + */ +struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, + loff_t pos) +{ + if (!pos) + return SEQ_START_TOKEN; + + return seq_hlist_start_rcu(head, pos - 1); +} +EXPORT_SYMBOL(seq_hlist_start_head_rcu); + +/** + * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU + * @v: the current iterator + * @head: the head of the hlist + * @ppos: the current position + * + * Called at seq_file->op->next(). + * + * This list-traversal primitive may safely run concurrently with + * the _rcu list-mutation primitives such as hlist_add_head_rcu() + * as long as the traversal is guarded by rcu_read_lock(). + */ +struct hlist_node *seq_hlist_next_rcu(void *v, + struct hlist_head *head, + loff_t *ppos) +{ + struct hlist_node *node = v; + + ++*ppos; + if (v == SEQ_START_TOKEN) + return rcu_dereference(head->first); + else + return rcu_dereference(node->next); +} +EXPORT_SYMBOL(seq_hlist_next_rcu); + +/** + * seq_hlist_start_precpu - start an iteration of a percpu hlist array + * @head: pointer to percpu array of struct hlist_heads + * @cpu: pointer to cpu "cursor" + * @pos: start position of sequence + * + * Called at seq_file->op->start(). + */ +struct hlist_node * +seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) +{ + struct hlist_node *node; + + for_each_possible_cpu(*cpu) { + hlist_for_each(node, per_cpu_ptr(head, *cpu)) { + if (pos-- == 0) + return node; + } + } + return NULL; +} +EXPORT_SYMBOL(seq_hlist_start_percpu); + +/** + * seq_hlist_next_percpu - move to the next position of the percpu hlist array + * @v: pointer to current hlist_node + * @head: pointer to percpu array of struct hlist_heads + * @cpu: pointer to cpu "cursor" + * @pos: start position of sequence + * + * Called at seq_file->op->next(). + */ +struct hlist_node * +seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, + int *cpu, loff_t *pos) +{ + struct hlist_node *node = v; + + ++*pos; + + if (node->next) + return node->next; + + for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; + *cpu = cpumask_next(*cpu, cpu_possible_mask)) { + struct hlist_head *bucket = per_cpu_ptr(head, *cpu); + + if (!hlist_empty(bucket)) + return bucket->first; + } + return NULL; +} +EXPORT_SYMBOL(seq_hlist_next_percpu); |