read job id from proc

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;
 

drivers/staging/lustre/lustre/Kconfig

@@ -1,6 +1,6 @@
 config LUSTRE_FS
 	tristate "Lustre file system client support"
-	depends on INET && m && !MIPS && !XTENSA && !SUPERH
+	depends on INET && m
 	select LNET
 	select CRYPTO
 	select CRYPTO_CRC32

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);

drivers/staging/lustre/lustre/llite/vvp_io.c

@@ -1133,8 +1133,11 @@ int vvp_io_init(const struct lu_env *env, struct cl_object *obj,
 		 *
 		 * it's not accurate if the file is shared by different
 		 * jobs.
+		 *
+		 * Save lookup jobid in first io and cache it forever.
 		 */
-		lustre_get_jobid(lli->lli_jobid);
+		if (lli->lli_jobid[0] == '\0')
+			lustre_get_jobid(lli->lli_jobid);
 	} else if (io->ci_type == CIT_SETATTR) {
 		if (!cl_io_is_trunc(io))
 			io->ci_lockreq = CILR_MANDATORY;

drivers/staging/lustre/lustre/obdclass/class_obd.c

@@ -96,6 +96,98 @@ EXPORT_SYMBOL(obd_dirty_transit_pages);
 char obd_jobid_var[JOBSTATS_JOBID_VAR_MAX_LEN + 1] = JOBSTATS_DISABLE;
 EXPORT_SYMBOL(obd_jobid_var);
 
+static char *self_environ_file = "/proc/self/environ";
+static int obd_get_environ(const char *key, char *value, int *val_len)
+{
+	struct path path;
+	struct file *filp = NULL;
+	int buf_len = PAGE_CACHE_SIZE;
+	int key_len = strlen(key);
+	char *buffer = NULL;
+	loff_t pos = 0;
+	int rc;
+
+	buffer = kmalloc(buf_len, GFP_USER);
+	if (!buffer)
+		return -ENOMEM;
+
+	rc = kern_path(self_environ_file, LOOKUP_FOLLOW, &path);
+	if (rc)
+		goto out;
+
+	filp = dentry_open(&path, O_RDONLY, current_cred());
+	if (IS_ERR(filp)) {
+		rc = PTR_ERR(filp);
+		filp = NULL;
+		goto out;
+	}
+
+	/* loop reading... */
+	while (1) {
+		int scan_len, this_len;
+		char *env_start, *env_end;
+		rc = kernel_read(filp, pos, buffer, buf_len);
+		if (rc <= 0)
+			break;
+
+		pos += rc;
+		/* 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 = rc;
+		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");
+					rc = -EINVAL;
+					goto out;
+				}
+				pos -= 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;
+				rc = 0;
+				goto out;
+			}
+
+			scan_len -= (env_end - env_start + 1);
+			env_start = env_end + 1;
+		}
+	}
+	if (rc >= 0)
+		rc = -ENOENT;
+out:
+	if (filp)
+		fput(filp);
+	if (buffer)
+		kfree(buffer);
+	return rc;
+}
+
 /* Get jobid of current process by reading the environment variable
  * stored in between the "env_start" & "env_end" of task struct.
  *
@@ -126,7 +218,7 @@ int lustre_get_jobid(char *jobid)
 		return 0;
 	}
 
-	rc = cfs_get_environ(obd_jobid_var, jobid, &jobid_len);
+	rc = obd_get_environ(obd_jobid_var, jobid, &jobid_len);
 	if (rc) {
 		if (rc == -EOVERFLOW) {
 			/* For the PBS_JOBID and LOADL_STEP_ID keys (which are
@@ -149,6 +241,8 @@ int lustre_get_jobid(char *jobid)
 			       "Get jobid for (%s) failed: rc = %d\n",
 			       obd_jobid_var, rc);
 		}
+	} else {
+		CDEBUG(D_INFO, "Got jobid for (%s) value (%s)\n", obd_jobid_var, jobid);
 	}
 	return rc;
 }