[PATCH 3/4] staging/lustre: remove cfs_get_environ and cfs_access_process_vm

From: Peng Tao
Date: Wed Oct 30 2013 - 07:31:28 EST


Reviewed-by: Niu Yawei <yawei.niu@xxxxxxxxx>
Signed-off-by: Peng Tao <bergwolf@xxxxxxxxx>
Signed-off-by: Andreas Dilger <andreas.dilger@xxxxxxxxx>
---
.../staging/lustre/include/linux/libcfs/curproc.h | 1 -
.../lustre/lustre/libcfs/linux/linux-curproc.c | 150 --------------------
2 files changed, 151 deletions(-)

diff --git a/drivers/staging/lustre/include/linux/libcfs/curproc.h b/drivers/staging/lustre/include/linux/libcfs/curproc.h
index de8e35b..1c49ef4 100644
--- a/drivers/staging/lustre/include/linux/libcfs/curproc.h
+++ b/drivers/staging/lustre/include/linux/libcfs/curproc.h
@@ -64,7 +64,6 @@ int cfs_curproc_groups_nr(void);
int current_is_32bit(void);
#define current_pid() (current->pid)
#define current_comm() (current->comm)
-int cfs_get_environ(const char *key, char *value, int *val_len);

typedef __u32 cfs_cap_t;

diff --git a/drivers/staging/lustre/lustre/libcfs/linux/linux-curproc.c b/drivers/staging/lustre/lustre/libcfs/linux/linux-curproc.c
index ea9e949..007f197 100644
--- a/drivers/staging/lustre/lustre/libcfs/linux/linux-curproc.c
+++ b/drivers/staging/lustre/lustre/libcfs/linux/linux-curproc.c
@@ -152,156 +152,6 @@ int current_is_32bit(void)
return is_compat_task();
}

-static int cfs_access_process_vm(struct task_struct *tsk, unsigned long addr,
- void *buf, int len, int write)
-{
- /* Just copied from kernel for the kernels which doesn't
- * have access_process_vm() exported */
- struct mm_struct *mm;
- struct vm_area_struct *vma;
- struct page *page;
- void *old_buf = buf;
-
- mm = get_task_mm(tsk);
- if (!mm)
- return 0;
-
- down_read(&mm->mmap_sem);
- /* ignore errors, just check how much was sucessfully transfered */
- while (len) {
- int bytes, rc, offset;
- void *maddr;
-
- rc = get_user_pages(tsk, mm, addr, 1,
- write, 1, &page, &vma);
- if (rc <= 0)
- break;
-
- bytes = len;
- offset = addr & (PAGE_SIZE-1);
- if (bytes > PAGE_SIZE-offset)
- bytes = PAGE_SIZE-offset;
-
- maddr = kmap(page);
- if (write) {
- copy_to_user_page(vma, page, addr,
- maddr + offset, buf, bytes);
- set_page_dirty_lock(page);
- } else {
- copy_from_user_page(vma, page, addr,
- buf, maddr + offset, bytes);
- }
- kunmap(page);
- page_cache_release(page);
- len -= bytes;
- buf += bytes;
- addr += bytes;
- }
- up_read(&mm->mmap_sem);
- mmput(mm);
-
- return buf - old_buf;
-}
-
-/* Read the environment variable of current process specified by @key. */
-int cfs_get_environ(const char *key, char *value, int *val_len)
-{
- struct mm_struct *mm;
- char *buffer, *tmp_buf = NULL;
- int buf_len = PAGE_CACHE_SIZE;
- int key_len = strlen(key);
- unsigned long addr;
- int rc;
-
- buffer = kmalloc(buf_len, GFP_USER);
- if (!buffer)
- return -ENOMEM;
-
- mm = get_task_mm(current);
- if (!mm) {
- kfree(buffer);
- return -EINVAL;
- }
-
- /* Avoid deadlocks on mmap_sem if called from sys_mmap_pgoff(),
- * which is already holding mmap_sem for writes. If some other
- * thread gets the write lock in the meantime, this thread will
- * block, but at least it won't deadlock on itself. LU-1735 */
- if (down_read_trylock(&mm->mmap_sem) == 0)
- return -EDEADLK;
- up_read(&mm->mmap_sem);
-
- addr = mm->env_start;
- while (addr < mm->env_end) {
- int this_len, retval, scan_len;
- char *env_start, *env_end;
-
- memset(buffer, 0, buf_len);
-
- this_len = min_t(int, mm->env_end - addr, buf_len);
- retval = cfs_access_process_vm(current, addr, buffer,
- this_len, 0);
- if (retval != this_len)
- break;
-
- addr += retval;
-
- /* Parse the buffer to find out the specified key/value pair.
- * The "key=value" entries are separated by '\0'. */
- env_start = buffer;
- scan_len = this_len;
- while (scan_len) {
- char *entry;
- int entry_len;
-
- env_end = memscan(env_start, '\0', scan_len);
- LASSERT(env_end >= env_start &&
- env_end <= env_start + scan_len);
-
- /* The last entry of this buffer cross the buffer
- * boundary, reread it in next cycle. */
- if (unlikely(env_end - env_start == scan_len)) {
- /* This entry is too large to fit in buffer */
- if (unlikely(scan_len == this_len)) {
- CERROR("Too long env variable.\n");
- GOTO(out, rc = -EINVAL);
- }
- addr -= scan_len;
- break;
- }
-
- entry = env_start;
- entry_len = env_end - env_start;
-
- /* Key length + length of '=' */
- if (entry_len > key_len + 1 &&
- !memcmp(entry, key, key_len)) {
- entry += key_len + 1;
- entry_len -= key_len + 1;
- /* The 'value' buffer passed in is too small.*/
- if (entry_len >= *val_len)
- GOTO(out, rc = -EOVERFLOW);
-
- memcpy(value, entry, entry_len);
- *val_len = entry_len;
- GOTO(out, rc = 0);
- }
-
- scan_len -= (env_end - env_start + 1);
- env_start = env_end + 1;
- }
- }
- GOTO(out, rc = -ENOENT);
-
-out:
- mmput(mm);
- kfree((void *)buffer);
- if (tmp_buf)
- kfree((void *)tmp_buf);
- return rc;
-}
-EXPORT_SYMBOL(cfs_get_environ);
-
EXPORT_SYMBOL(cfs_curproc_groups_nr);
EXPORT_SYMBOL(cfs_cap_raise);
EXPORT_SYMBOL(cfs_cap_lower);
--
1.7.9.5

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