linux-kernel - [PATCH] cifs: don't check for failure from mempool

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Message-ID: <87h91xxbd6.fsf@notabene.neil.brown.name>
Date:   Mon, 10 Apr 2017 12:08:53 +1000
From:   NeilBrown <neilb@...e.com>
To:     Steve French <sfrench@...ba.org>
Cc:     linux-cifs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] cifs: don't check for failure from mempool_alloc()


mempool_alloc() cannot fail if the gfp flags allow it to
sleep, and both GFP_FS allows for sleeping.

So these tests of the return value from mempool_alloc()
cannot be needed.

Signed-off-by: NeilBrown <neilb@...e.com>
---
 fs/cifs/misc.c          | 14 +++++---------
 fs/cifs/smb2transport.c | 30 +++++++++++++-----------------
 fs/cifs/transport.c     | 32 ++++++++++++++------------------
 3 files changed, 32 insertions(+), 44 deletions(-)

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index d3fb11529ed9..843787850435 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -167,13 +167,11 @@ cifs_buf_get(void)
 
 	/* clear the first few header bytes */
 	/* for most paths, more is cleared in header_assemble */
-	if (ret_buf) {
-		memset(ret_buf, 0, buf_size + 3);
-		atomic_inc(&bufAllocCount);
+	memset(ret_buf, 0, buf_size + 3);
+	atomic_inc(&bufAllocCount);
 #ifdef CONFIG_CIFS_STATS2
-		atomic_inc(&totBufAllocCount);
+	atomic_inc(&totBufAllocCount);
 #endif /* CONFIG_CIFS_STATS2 */
-	}
 
 	return ret_buf;
 }
@@ -201,15 +199,13 @@ cifs_small_buf_get(void)
    albeit slightly larger than necessary and maxbuffersize
    defaults to this and can not be bigger */
 	ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
-	if (ret_buf) {
 	/* No need to clear memory here, cleared in header assemble */
 	/*	memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
-		atomic_inc(&smBufAllocCount);
+	atomic_inc(&smBufAllocCount);
 #ifdef CONFIG_CIFS_STATS2
-		atomic_inc(&totSmBufAllocCount);
+	atomic_inc(&totSmBufAllocCount);
 #endif /* CONFIG_CIFS_STATS2 */
 
-	}
 	return ret_buf;
 }
 
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 506b67fc93d9..c69ec96e92ac 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -538,23 +538,19 @@ smb2_mid_entry_alloc(const struct smb2_sync_hdr *shdr,
 	}
 
 	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
-	if (temp == NULL)
-		return temp;
-	else {
-		memset(temp, 0, sizeof(struct mid_q_entry));
-		temp->mid = le64_to_cpu(shdr->MessageId);
-		temp->pid = current->pid;
-		temp->command = shdr->Command; /* Always LE */
-		temp->when_alloc = jiffies;
-		temp->server = server;
-
-		/*
-		 * The default is for the mid to be synchronous, so the
-		 * default callback just wakes up the current task.
-		 */
-		temp->callback = cifs_wake_up_task;
-		temp->callback_data = current;
-	}
+	memset(temp, 0, sizeof(struct mid_q_entry));
+	temp->mid = le64_to_cpu(shdr->MessageId);
+	temp->pid = current->pid;
+	temp->command = shdr->Command; /* Always LE */
+	temp->when_alloc = jiffies;
+	temp->server = server;
+
+	/*
+	 * The default is for the mid to be synchronous, so the
+	 * default callback just wakes up the current task.
+	 */
+	temp->callback = cifs_wake_up_task;
+	temp->callback_data = current;
 
 	atomic_inc(&midCount);
 	temp->mid_state = MID_REQUEST_ALLOCATED;
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index f6e13a977fc8..4d64b5b8fc9c 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -55,26 +55,22 @@ AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
 	}
 
 	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
-	if (temp == NULL)
-		return temp;
-	else {
-		memset(temp, 0, sizeof(struct mid_q_entry));
-		temp->mid = get_mid(smb_buffer);
-		temp->pid = current->pid;
-		temp->command = cpu_to_le16(smb_buffer->Command);
-		cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
+	memset(temp, 0, sizeof(struct mid_q_entry));
+	temp->mid = get_mid(smb_buffer);
+	temp->pid = current->pid;
+	temp->command = cpu_to_le16(smb_buffer->Command);
+	cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
 	/*	do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
-		/* when mid allocated can be before when sent */
-		temp->when_alloc = jiffies;
-		temp->server = server;
+	/* when mid allocated can be before when sent */
+	temp->when_alloc = jiffies;
+	temp->server = server;
 
-		/*
-		 * The default is for the mid to be synchronous, so the
-		 * default callback just wakes up the current task.
-		 */
-		temp->callback = cifs_wake_up_task;
-		temp->callback_data = current;
-	}
+	/*
+	 * The default is for the mid to be synchronous, so the
+	 * default callback just wakes up the current task.
+	 */
+	temp->callback = cifs_wake_up_task;
+	temp->callback_data = current;
 
 	atomic_inc(&midCount);
 	temp->mid_state = MID_REQUEST_ALLOCATED;
-- 
2.12.2


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