* [PATCH v2 0/2] Move BTRFS RCU string to common library
@ 2014-09-19 9:01 Omar Sandoval
2014-09-19 9:01 ` [PATCH v2 1/2] Return a value from printk_ratelimited Omar Sandoval
` (2 more replies)
0 siblings, 3 replies; 13+ messages in thread
From: Omar Sandoval @ 2014-09-19 9:01 UTC (permalink / raw)
To: Chris Mason, Josef Bacik, linux-btrfs, Paul E. McKenney,
Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Lai Jiangshan,
linux-kernel
This patch series moves the generic RCU string library used internally by BTRFS
to be accessible by anyone. It provides printk_in_rcu and
printk_ratelimited_in_rcu to print these strings. In order to avoid a weird
inconsistency between the two, the first patch fixes printk_ratelimited so it
passes on the return value from printk.
The second patch actually moves the RCU string library. Version 2 passes on the
return values from printk{,_ratelimited} and fixes some style issues.
Omar Sandoval (2):
Return a value from printk_ratelimited
Move BTRFS RCU string to common library
fs/btrfs/check-integrity.c | 6 +--
fs/btrfs/dev-replace.c | 19 +++++-----
fs/btrfs/disk-io.c | 6 +--
fs/btrfs/extent_io.c | 4 +-
fs/btrfs/ioctl.c | 4 +-
fs/btrfs/raid56.c | 2 +-
fs/btrfs/rcu-string.h | 56 ----------------------------
fs/btrfs/scrub.c | 15 ++++----
fs/btrfs/super.c | 2 +-
fs/btrfs/volumes.c | 14 +++----
include/linux/printk.h | 4 +-
include/linux/rcustring.h | 91 ++++++++++++++++++++++++++++++++++++++++++++++
12 files changed, 131 insertions(+), 92 deletions(-)
delete mode 100644 fs/btrfs/rcu-string.h
create mode 100644 include/linux/rcustring.h
--
2.1.0
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v2 1/2] Return a value from printk_ratelimited
2014-09-19 9:01 [PATCH v2 0/2] Move BTRFS RCU string to common library Omar Sandoval
@ 2014-09-19 9:01 ` Omar Sandoval
2014-09-19 17:21 ` Steven Rostedt
2014-09-19 9:01 ` [PATCH v2 2/2] Move BTRFS RCU string to common library Omar Sandoval
2014-09-19 15:45 ` [PATCH v2 0/2] " Paul E. McKenney
2 siblings, 1 reply; 13+ messages in thread
From: Omar Sandoval @ 2014-09-19 9:01 UTC (permalink / raw)
To: Chris Mason, Josef Bacik, linux-btrfs, Paul E. McKenney,
Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Lai Jiangshan,
linux-kernel
printk returns an integer; there's no reason for printk_ratelimited to swallow
it.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
---
include/linux/printk.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/printk.h b/include/linux/printk.h
index d78125f..67534bc 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -343,12 +343,14 @@ extern asmlinkage void dump_stack(void) __cold;
#ifdef CONFIG_PRINTK
#define printk_ratelimited(fmt, ...) \
({ \
+ int __ret = 0; \
static DEFINE_RATELIMIT_STATE(_rs, \
DEFAULT_RATELIMIT_INTERVAL, \
DEFAULT_RATELIMIT_BURST); \
\
if (__ratelimit(&_rs)) \
- printk(fmt, ##__VA_ARGS__); \
+ __ret = printk(fmt, ##__VA_ARGS__); \
+ __ret; \
})
#else
#define printk_ratelimited(fmt, ...) \
--
2.1.0
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v2 2/2] Move BTRFS RCU string to common library
2014-09-19 9:01 [PATCH v2 0/2] Move BTRFS RCU string to common library Omar Sandoval
2014-09-19 9:01 ` [PATCH v2 1/2] Return a value from printk_ratelimited Omar Sandoval
@ 2014-09-19 9:01 ` Omar Sandoval
2014-09-26 23:25 ` josh
2014-09-19 15:45 ` [PATCH v2 0/2] " Paul E. McKenney
2 siblings, 1 reply; 13+ messages in thread
From: Omar Sandoval @ 2014-09-19 9:01 UTC (permalink / raw)
To: Chris Mason, Josef Bacik, linux-btrfs, Paul E. McKenney,
Josh Triplett, Steven Rostedt, Mathieu Desnoyers, Lai Jiangshan,
linux-kernel
The RCU-friendy string API used internally by BTRFS is generic enough for
common use. This doesn't add any new functionality, but instead just moves the
code and documents the existing API.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
---
fs/btrfs/check-integrity.c | 6 +--
fs/btrfs/dev-replace.c | 19 +++++-----
fs/btrfs/disk-io.c | 6 +--
fs/btrfs/extent_io.c | 4 +-
fs/btrfs/ioctl.c | 4 +-
fs/btrfs/raid56.c | 2 +-
fs/btrfs/rcu-string.h | 56 ----------------------------
fs/btrfs/scrub.c | 15 ++++----
fs/btrfs/super.c | 2 +-
fs/btrfs/volumes.c | 14 +++----
include/linux/rcustring.h | 91 ++++++++++++++++++++++++++++++++++++++++++++++
11 files changed, 128 insertions(+), 91 deletions(-)
delete mode 100644 fs/btrfs/rcu-string.h
create mode 100644 include/linux/rcustring.h
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index ce92ae3..4ccd7da 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -94,6 +94,7 @@
#include <linux/mutex.h>
#include <linux/genhd.h>
#include <linux/blkdev.h>
+#include <linux/rcustring.h>
#include "ctree.h"
#include "disk-io.h"
#include "hash.h"
@@ -103,7 +104,6 @@
#include "print-tree.h"
#include "locking.h"
#include "check-integrity.h"
-#include "rcu-string.h"
#define BTRFSIC_BLOCK_HASHTABLE_SIZE 0x10000
#define BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE 0x10000
@@ -851,8 +851,8 @@ static int btrfsic_process_superblock_dev_mirror(
printk_in_rcu(KERN_INFO "New initial S-block (bdev %p, %s)"
" @%llu (%s/%llu/%d)\n",
superblock_bdev,
- rcu_str_deref(device->name), dev_bytenr,
- dev_state->name, dev_bytenr,
+ rcu_string_dereference(device->name),
+ dev_bytenr, dev_state->name, dev_bytenr,
superblock_mirror_num);
list_add(&superblock_tmp->all_blocks_node,
&state->all_blocks_list);
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index eea26e1..87d10cc 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -25,6 +25,7 @@
#include <linux/capability.h>
#include <linux/kthread.h>
#include <linux/math64.h>
+#include <linux/rcustring.h>
#include <asm/div64.h>
#include "ctree.h"
#include "extent_map.h"
@@ -34,7 +35,6 @@
#include "volumes.h"
#include "async-thread.h"
#include "check-integrity.h"
-#include "rcu-string.h"
#include "dev-replace.h"
#include "sysfs.h"
@@ -376,9 +376,9 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
printk_in_rcu(KERN_INFO
"BTRFS: dev_replace from %s (devid %llu) to %s started\n",
src_device->missing ? "<missing disk>" :
- rcu_str_deref(src_device->name),
+ rcu_string_dereference(src_device->name),
src_device->devid,
- rcu_str_deref(tgt_device->name));
+ rcu_string_dereference(tgt_device->name));
tgt_device->total_bytes = src_device->total_bytes;
tgt_device->disk_total_bytes = src_device->disk_total_bytes;
@@ -528,9 +528,10 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
printk_in_rcu(KERN_ERR
"BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n",
src_device->missing ? "<missing disk>" :
- rcu_str_deref(src_device->name),
+ rcu_string_dereference(src_device->name),
src_device->devid,
- rcu_str_deref(tgt_device->name), scrub_ret);
+ rcu_string_dereference(tgt_device->name),
+ scrub_ret);
btrfs_dev_replace_unlock(dev_replace);
mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
mutex_unlock(&root->fs_info->chunk_mutex);
@@ -544,9 +545,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
printk_in_rcu(KERN_INFO
"BTRFS: dev_replace from %s (devid %llu) to %s) finished\n",
src_device->missing ? "<missing disk>" :
- rcu_str_deref(src_device->name),
+ rcu_string_dereference(src_device->name),
src_device->devid,
- rcu_str_deref(tgt_device->name));
+ rcu_string_dereference(tgt_device->name));
tgt_device->is_tgtdev_for_dev_replace = 0;
tgt_device->devid = src_device->devid;
src_device->devid = BTRFS_DEV_REPLACE_DEVID;
@@ -805,10 +806,10 @@ static int btrfs_dev_replace_kthread(void *data)
printk_in_rcu(KERN_INFO
"BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n",
dev_replace->srcdev->missing ? "<missing disk>" :
- rcu_str_deref(dev_replace->srcdev->name),
+ rcu_string_dereference(dev_replace->srcdev->name),
dev_replace->srcdev->devid,
dev_replace->tgtdev ?
- rcu_str_deref(dev_replace->tgtdev->name) :
+ rcu_string_dereference(dev_replace->tgtdev->name) :
"<missing target disk>",
(unsigned int)progress);
}
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a1d36e6..00f7441 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -31,6 +31,7 @@
#include <linux/ratelimit.h>
#include <linux/uuid.h>
#include <linux/semaphore.h>
+#include <linux/rcustring.h>
#include <asm/unaligned.h>
#include "ctree.h"
#include "disk-io.h"
@@ -44,7 +45,6 @@
#include "free-space-cache.h"
#include "inode-map.h"
#include "check-integrity.h"
-#include "rcu-string.h"
#include "dev-replace.h"
#include "raid56.h"
#include "sysfs.h"
@@ -3059,7 +3059,7 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
printk_ratelimited_in_rcu(KERN_WARNING "BTRFS: lost page write due to "
"I/O error on %s\n",
- rcu_str_deref(device->name));
+ rcu_string_dereference(device->name));
/* note, we dont' set_buffer_write_io_error because we have
* our own ways of dealing with the IO errors
*/
@@ -3247,7 +3247,7 @@ static int write_dev_flush(struct btrfs_device *device, int wait)
if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
printk_in_rcu("BTRFS: disabling barriers on dev %s\n",
- rcu_str_deref(device->name));
+ rcu_string_dereference(device->name));
device->nobarriers = 1;
} else if (!bio_flagged(bio, BIO_UPTODATE)) {
ret = -EIO;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index af0359d..441dccd 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -11,6 +11,7 @@
#include <linux/pagevec.h>
#include <linux/prefetch.h>
#include <linux/cleancache.h>
+#include <linux/rcustring.h>
#include "extent_io.h"
#include "extent_map.h"
#include "ctree.h"
@@ -18,7 +19,6 @@
#include "volumes.h"
#include "check-integrity.h"
#include "locking.h"
-#include "rcu-string.h"
#include "backref.h"
static struct kmem_cache *extent_state_cache;
@@ -2065,7 +2065,7 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64 start,
printk_ratelimited_in_rcu(KERN_INFO
"BTRFS: read error corrected: ino %lu off %llu "
"(dev %s sector %llu)\n", page->mapping->host->i_ino,
- start, rcu_str_deref(dev->name), sector);
+ start, rcu_string_dereference(dev->name), sector);
bio_put(bio);
return 0;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 8a8e298..9d4cd72 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -44,6 +44,7 @@
#include <linux/uuid.h>
#include <linux/btrfs.h>
#include <linux/uaccess.h>
+#include <linux/rcustring.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
@@ -53,7 +54,6 @@
#include "locking.h"
#include "inode-map.h"
#include "backref.h"
-#include "rcu-string.h"
#include "send.h"
#include "dev-replace.h"
#include "props.h"
@@ -1583,7 +1583,7 @@ static noinline int btrfs_ioctl_resize(struct file *file,
new_size *= root->sectorsize;
printk_in_rcu(KERN_INFO "BTRFS: new size for %s is %llu\n",
- rcu_str_deref(device->name), new_size);
+ rcu_string_dereference(device->name), new_size);
if (new_size > old_size) {
trans = btrfs_start_transaction(root, 0);
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 0a6b6e4..eecf738 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -32,6 +32,7 @@
#include <linux/list_sort.h>
#include <linux/raid/xor.h>
#include <linux/vmalloc.h>
+#include <linux/rcustring.h>
#include <asm/div64.h>
#include "ctree.h"
#include "extent_map.h"
@@ -42,7 +43,6 @@
#include "raid56.h"
#include "async-thread.h"
#include "check-integrity.h"
-#include "rcu-string.h"
/* set when additional merges to this rbio are not allowed */
#define RBIO_RMW_LOCKED_BIT 1
diff --git a/fs/btrfs/rcu-string.h b/fs/btrfs/rcu-string.h
deleted file mode 100644
index 9e111e4..0000000
--- a/fs/btrfs/rcu-string.h
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright (C) 2012 Red Hat. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-
-struct rcu_string {
- struct rcu_head rcu;
- char str[0];
-};
-
-static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t mask)
-{
- size_t len = strlen(src) + 1;
- struct rcu_string *ret = kzalloc(sizeof(struct rcu_string) +
- (len * sizeof(char)), mask);
- if (!ret)
- return ret;
- strncpy(ret->str, src, len);
- return ret;
-}
-
-static inline void rcu_string_free(struct rcu_string *str)
-{
- if (str)
- kfree_rcu(str, rcu);
-}
-
-#define printk_in_rcu(fmt, ...) do { \
- rcu_read_lock(); \
- printk(fmt, __VA_ARGS__); \
- rcu_read_unlock(); \
-} while (0)
-
-#define printk_ratelimited_in_rcu(fmt, ...) do { \
- rcu_read_lock(); \
- printk_ratelimited(fmt, __VA_ARGS__); \
- rcu_read_unlock(); \
-} while (0)
-
-#define rcu_str_deref(rcu_str) ({ \
- struct rcu_string *__str = rcu_dereference(rcu_str); \
- __str->str; \
-})
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index f4a41f3..62e335f 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -18,6 +18,7 @@
#include <linux/blkdev.h>
#include <linux/ratelimit.h>
+#include <linux/rcustring.h>
#include "ctree.h"
#include "volumes.h"
#include "disk-io.h"
@@ -27,7 +28,6 @@
#include "extent_io.h"
#include "dev-replace.h"
#include "check-integrity.h"
-#include "rcu-string.h"
#include "raid56.h"
/*
@@ -519,7 +519,8 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
"%s, sector %llu, root %llu, inode %llu, offset %llu, "
"length %llu, links %u (path: %s)\n", swarn->errstr,
- swarn->logical, rcu_str_deref(swarn->dev->name),
+ swarn->logical,
+ rcu_string_dereference(swarn->dev->name),
(unsigned long long)swarn->sector, root, inum, offset,
min(isize - offset, (u64)PAGE_SIZE), nlink,
(char *)(unsigned long)ipath->fspath->val[i]);
@@ -531,7 +532,7 @@ err:
printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
"%s, sector %llu, root %llu, inode %llu, offset %llu: path "
"resolving failed with ret=%d\n", swarn->errstr,
- swarn->logical, rcu_str_deref(swarn->dev->name),
+ swarn->logical, rcu_string_dereference(swarn->dev->name),
(unsigned long long)swarn->sector, root, inum, offset, ret);
free_ipath(ipath);
@@ -595,7 +596,7 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
"BTRFS: %s at logical %llu on dev %s, "
"sector %llu: metadata %s (level %d) in tree "
"%llu\n", errstr, swarn.logical,
- rcu_str_deref(dev->name),
+ rcu_string_dereference(dev->name),
(unsigned long long)swarn.sector,
ref_level ? "node" : "leaf",
ret < 0 ? -1 : ref_level,
@@ -796,7 +797,7 @@ out:
num_uncorrectable_read_errors);
printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
"unable to fixup (nodatasum) error at logical %llu on dev %s\n",
- fixup->logical, rcu_str_deref(fixup->dev->name));
+ fixup->logical, rcu_string_dereference(fixup->dev->name));
}
btrfs_free_path(path);
@@ -1198,7 +1199,7 @@ corrected_error:
spin_unlock(&sctx->stat_lock);
printk_ratelimited_in_rcu(KERN_ERR
"BTRFS: fixed up error at logical %llu on dev %s\n",
- logical, rcu_str_deref(dev->name));
+ logical, rcu_string_dereference(dev->name));
}
} else {
did_not_correct_error:
@@ -1207,7 +1208,7 @@ did_not_correct_error:
spin_unlock(&sctx->stat_lock);
printk_ratelimited_in_rcu(KERN_ERR
"BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
- logical, rcu_str_deref(dev->name));
+ logical, rcu_string_dereference(dev->name));
}
out:
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index c4124de..cf4db62 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -42,6 +42,7 @@
#include <linux/cleancache.h>
#include <linux/ratelimit.h>
#include <linux/btrfs.h>
+#include <linux/rcustring.h>
#include "delayed-inode.h"
#include "ctree.h"
#include "disk-io.h"
@@ -54,7 +55,6 @@
#include "volumes.h"
#include "export.h"
#include "compression.h"
-#include "rcu-string.h"
#include "dev-replace.h"
#include "free-space-cache.h"
#include "backref.h"
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 340a92d..8b1e5e8 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -27,6 +27,7 @@
#include <linux/kthread.h>
#include <linux/raid/pq.h>
#include <linux/semaphore.h>
+#include <linux/rcustring.h>
#include <asm/div64.h>
#include "ctree.h"
#include "extent_map.h"
@@ -37,7 +38,6 @@
#include "raid56.h"
#include "async-thread.h"
#include "check-integrity.h"
-#include "rcu-string.h"
#include "math.h"
#include "dev-replace.h"
#include "sysfs.h"
@@ -6323,7 +6323,7 @@ static int update_dev_stat_item(struct btrfs_trans_handle *trans,
if (ret < 0) {
printk_in_rcu(KERN_WARNING "BTRFS: "
"error %d while searching for dev_stats item for device %s!\n",
- ret, rcu_str_deref(device->name));
+ ret, rcu_string_dereference(device->name));
goto out;
}
@@ -6334,7 +6334,7 @@ static int update_dev_stat_item(struct btrfs_trans_handle *trans,
if (ret != 0) {
printk_in_rcu(KERN_WARNING "BTRFS: "
"delete too small dev_stats item for device %s failed %d!\n",
- rcu_str_deref(device->name), ret);
+ rcu_string_dereference(device->name), ret);
goto out;
}
ret = 1;
@@ -6347,8 +6347,8 @@ static int update_dev_stat_item(struct btrfs_trans_handle *trans,
&key, sizeof(*ptr));
if (ret < 0) {
printk_in_rcu(KERN_WARNING "BTRFS: "
- "insert dev_stats item for device %s failed %d!\n",
- rcu_str_deref(device->name), ret);
+ "insert dev_stats item for device %s failed %d!\n",
+ rcu_string_dereference(device->name), ret);
goto out;
}
}
@@ -6402,7 +6402,7 @@ static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
return;
printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
"bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
- rcu_str_deref(dev->name),
+ rcu_string_dereference(dev->name),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
@@ -6422,7 +6422,7 @@ static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
printk_in_rcu(KERN_INFO "BTRFS: "
"bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
- rcu_str_deref(dev->name),
+ rcu_string_dereference(dev->name),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
diff --git a/include/linux/rcustring.h b/include/linux/rcustring.h
new file mode 100644
index 0000000..18980e9
--- /dev/null
+++ b/include/linux/rcustring.h
@@ -0,0 +1,91 @@
+/*
+ * RCU-friendly strings
+ *
+ * Copyright (C) 2012 Red Hat. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ */
+
+#ifndef _LINUX_RCUSTRING_H
+#define _LINUX_RCUSTRING_H
+
+struct rcu_string {
+ struct rcu_head rcu;
+ char str[0];
+};
+
+/**
+ * rcu_string_strdup() - create an RCU string from a string
+ * @src: The string to copy
+ * @flags: Flags for kmalloc
+ */
+static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t flags)
+{
+ struct rcu_string *ret;
+ size_t len = strlen(src) + 1;
+
+ ret = kmalloc(sizeof(struct rcu_string) + (len * sizeof(char)), flags);
+ if (!ret)
+ return ret;
+ memcpy(ret->str, src, len);
+ return ret;
+}
+
+/**
+ * rcu_string_free() - free an RCU string
+ * @str: The string
+ */
+static inline void rcu_string_free(struct rcu_string *str)
+{
+ if (str)
+ kfree_rcu(str, rcu);
+}
+
+/*
+ * rcu_string_dereference() - dereference an RCU string
+ * @str: The string
+ *
+ * Like rcu_dereference, this must be done in an RCU critical section.
+ */
+static inline char *rcu_string_dereference(struct rcu_string *rcu_str)
+{
+ return rcu_dereference(rcu_str)->str;
+}
+
+/**
+ * printk_in_rcu() - printk in an RCU read-side critical section
+ */
+#define printk_in_rcu(fmt, ...) \
+({ \
+ int __ret; \
+ rcu_read_lock(); \
+ __ret = printk(fmt, __VA_ARGS__); \
+ rcu_read_unlock(); \
+ __ret; \
+})
+
+/**
+ * printk_ratelimited_in_rcu() - printk in an RCU read-side critical section
+ */
+#define printk_ratelimited_in_rcu(fmt, ...) \
+({ \
+ int __ret; \
+ rcu_read_lock(); \
+ __ret = printk_ratelimited(fmt, __VA_ARGS__); \
+ rcu_read_unlock(); \
+ __ret; \
+})
+
+#endif
--
2.1.0
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH v2 0/2] Move BTRFS RCU string to common library
2014-09-19 9:01 [PATCH v2 0/2] Move BTRFS RCU string to common library Omar Sandoval
2014-09-19 9:01 ` [PATCH v2 1/2] Return a value from printk_ratelimited Omar Sandoval
2014-09-19 9:01 ` [PATCH v2 2/2] Move BTRFS RCU string to common library Omar Sandoval
@ 2014-09-19 15:45 ` Paul E. McKenney
2014-09-19 15:47 ` Chris Mason
2 siblings, 1 reply; 13+ messages in thread
From: Paul E. McKenney @ 2014-09-19 15:45 UTC (permalink / raw)
To: Omar Sandoval
Cc: Chris Mason, Josef Bacik, linux-btrfs, Josh Triplett,
Steven Rostedt, Mathieu Desnoyers, Lai Jiangshan, linux-kernel
On Fri, Sep 19, 2014 at 02:01:28AM -0700, Omar Sandoval wrote:
> This patch series moves the generic RCU string library used internally by BTRFS
> to be accessible by anyone. It provides printk_in_rcu and
> printk_ratelimited_in_rcu to print these strings. In order to avoid a weird
> inconsistency between the two, the first patch fixes printk_ratelimited so it
> passes on the return value from printk.
>
> The second patch actually moves the RCU string library. Version 2 passes on the
> return values from printk{,_ratelimited} and fixes some style issues.
>
> Omar Sandoval (2):
For the series:
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> Return a value from printk_ratelimited
> Move BTRFS RCU string to common library
>
> fs/btrfs/check-integrity.c | 6 +--
> fs/btrfs/dev-replace.c | 19 +++++-----
> fs/btrfs/disk-io.c | 6 +--
> fs/btrfs/extent_io.c | 4 +-
> fs/btrfs/ioctl.c | 4 +-
> fs/btrfs/raid56.c | 2 +-
> fs/btrfs/rcu-string.h | 56 ----------------------------
> fs/btrfs/scrub.c | 15 ++++----
> fs/btrfs/super.c | 2 +-
> fs/btrfs/volumes.c | 14 +++----
> include/linux/printk.h | 4 +-
> include/linux/rcustring.h | 91 ++++++++++++++++++++++++++++++++++++++++++++++
> 12 files changed, 131 insertions(+), 92 deletions(-)
> delete mode 100644 fs/btrfs/rcu-string.h
> create mode 100644 include/linux/rcustring.h
>
> --
> 2.1.0
>
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 0/2] Move BTRFS RCU string to common library
2014-09-19 15:45 ` [PATCH v2 0/2] " Paul E. McKenney
@ 2014-09-19 15:47 ` Chris Mason
2014-09-19 16:05 ` Paul E. McKenney
0 siblings, 1 reply; 13+ messages in thread
From: Chris Mason @ 2014-09-19 15:47 UTC (permalink / raw)
To: paulmck, Omar Sandoval
Cc: Josef Bacik, linux-btrfs, Josh Triplett, Steven Rostedt,
Mathieu Desnoyers, Lai Jiangshan, linux-kernel
On 09/19/2014 11:45 AM, Paul E. McKenney wrote:
> On Fri, Sep 19, 2014 at 02:01:28AM -0700, Omar Sandoval wrote:
>> This patch series moves the generic RCU string library used internally by BTRFS
>> to be accessible by anyone. It provides printk_in_rcu and
>> printk_ratelimited_in_rcu to print these strings. In order to avoid a weird
>> inconsistency between the two, the first patch fixes printk_ratelimited so it
>> passes on the return value from printk.
>>
>> The second patch actually moves the RCU string library. Version 2 passes on the
>> return values from printk{,_ratelimited} and fixes some style issues.
>>
>> Omar Sandoval (2):
>
> For the series:
>
> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Fine by me too, Paul, do you want to merge it in?
-chris
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 0/2] Move BTRFS RCU string to common library
2014-09-19 15:47 ` Chris Mason
@ 2014-09-19 16:05 ` Paul E. McKenney
2014-09-19 16:22 ` Chris Mason
0 siblings, 1 reply; 13+ messages in thread
From: Paul E. McKenney @ 2014-09-19 16:05 UTC (permalink / raw)
To: Chris Mason
Cc: Omar Sandoval, Josef Bacik, linux-btrfs, Josh Triplett,
Steven Rostedt, Mathieu Desnoyers, Lai Jiangshan, linux-kernel
On Fri, Sep 19, 2014 at 11:47:53AM -0400, Chris Mason wrote:
>
>
> On 09/19/2014 11:45 AM, Paul E. McKenney wrote:
> > On Fri, Sep 19, 2014 at 02:01:28AM -0700, Omar Sandoval wrote:
> >> This patch series moves the generic RCU string library used internally by BTRFS
> >> to be accessible by anyone. It provides printk_in_rcu and
> >> printk_ratelimited_in_rcu to print these strings. In order to avoid a weird
> >> inconsistency between the two, the first patch fixes printk_ratelimited so it
> >> passes on the return value from printk.
> >>
> >> The second patch actually moves the RCU string library. Version 2 passes on the
> >> return values from printk{,_ratelimited} and fixes some style issues.
> >>
> >> Omar Sandoval (2):
> >
> > For the series:
> >
> > Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
>
> Fine by me too, Paul, do you want to merge it in?
I would be happy to.
Are you thinking in terms of 3.18 or 3.19? These look OK either way, but
thought I should check.
Thanx, Paul
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 0/2] Move BTRFS RCU string to common library
2014-09-19 16:05 ` Paul E. McKenney
@ 2014-09-19 16:22 ` Chris Mason
2014-09-21 13:25 ` Paul E. McKenney
0 siblings, 1 reply; 13+ messages in thread
From: Chris Mason @ 2014-09-19 16:22 UTC (permalink / raw)
To: paulmck
Cc: Omar Sandoval, Josef Bacik, linux-btrfs, Josh Triplett,
Steven Rostedt, Mathieu Desnoyers, Lai Jiangshan, linux-kernel
On 09/19/2014 12:05 PM, Paul E. McKenney wrote:
> On Fri, Sep 19, 2014 at 11:47:53AM -0400, Chris Mason wrote:
>>
>>
>> On 09/19/2014 11:45 AM, Paul E. McKenney wrote:
>>> On Fri, Sep 19, 2014 at 02:01:28AM -0700, Omar Sandoval wrote:
>>>> This patch series moves the generic RCU string library used internally by BTRFS
>>>> to be accessible by anyone. It provides printk_in_rcu and
>>>> printk_ratelimited_in_rcu to print these strings. In order to avoid a weird
>>>> inconsistency between the two, the first patch fixes printk_ratelimited so it
>>>> passes on the return value from printk.
>>>>
>>>> The second patch actually moves the RCU string library. Version 2 passes on the
>>>> return values from printk{,_ratelimited} and fixes some style issues.
>>>>
>>>> Omar Sandoval (2):
>>>
>>> For the series:
>>>
>>> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
>>
>> Fine by me too, Paul, do you want to merge it in?
>
> I would be happy to.
>
> Are you thinking in terms of 3.18 or 3.19? These look OK either way, but
> thought I should check.
Either way is fine with me. Actually this will have minor conflicts
with my current branch headed for-next, so I can resolve and send as a
stand alone pull.
-chris
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 1/2] Return a value from printk_ratelimited
2014-09-19 9:01 ` [PATCH v2 1/2] Return a value from printk_ratelimited Omar Sandoval
@ 2014-09-19 17:21 ` Steven Rostedt
2014-09-19 18:15 ` Joe Perches
0 siblings, 1 reply; 13+ messages in thread
From: Steven Rostedt @ 2014-09-19 17:21 UTC (permalink / raw)
To: Omar Sandoval
Cc: Chris Mason, Josef Bacik, linux-btrfs, Paul E. McKenney,
Josh Triplett, Mathieu Desnoyers, Lai Jiangshan, linux-kernel
On Fri, 19 Sep 2014 02:01:29 -0700
Omar Sandoval <osandov@osandov.com> wrote:
> printk returns an integer; there's no reason for printk_ratelimited to swallow
> it.
>
> Signed-off-by: Omar Sandoval <osandov@osandov.com>
> ---
> include/linux/printk.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/printk.h b/include/linux/printk.h
> index d78125f..67534bc 100644
> --- a/include/linux/printk.h
> +++ b/include/linux/printk.h
> @@ -343,12 +343,14 @@ extern asmlinkage void dump_stack(void) __cold;
> #ifdef CONFIG_PRINTK
> #define printk_ratelimited(fmt, ...) \
> ({ \
> + int __ret = 0; \
My only issues is with the "__ret" name.
It's not really unique enough. If something else uses __ret and does
printk_ratelimit("some fmt string %d\n", __ret);
This will not print the right value.
printk_ratelimit can be used almost anywhere thus using a really unique
value may be worth while here.
What about:
int ______r
?
-- Steve
> static DEFINE_RATELIMIT_STATE(_rs, \
> DEFAULT_RATELIMIT_INTERVAL, \
> DEFAULT_RATELIMIT_BURST); \
> \
> if (__ratelimit(&_rs)) \
> - printk(fmt, ##__VA_ARGS__); \
> + __ret = printk(fmt, ##__VA_ARGS__); \
> + __ret; \
> })
> #else
> #define printk_ratelimited(fmt, ...) \
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 1/2] Return a value from printk_ratelimited
2014-09-19 17:21 ` Steven Rostedt
@ 2014-09-19 18:15 ` Joe Perches
2014-09-21 13:25 ` Paul E. McKenney
0 siblings, 1 reply; 13+ messages in thread
From: Joe Perches @ 2014-09-19 18:15 UTC (permalink / raw)
To: Steven Rostedt
Cc: Omar Sandoval, Chris Mason, Josef Bacik, linux-btrfs,
Paul E. McKenney, Josh Triplett, Mathieu Desnoyers,
Lai Jiangshan, linux-kernel
On Fri, 2014-09-19 at 13:21 -0400, Steven Rostedt wrote:
> On Fri, 19 Sep 2014 02:01:29 -0700
> Omar Sandoval <osandov@osandov.com> wrote:
>
> > printk returns an integer; there's no reason for printk_ratelimited to swallow
> > it.
Except for the lack of usefulness of the return value itself.
See: https://lkml.org/lkml/2009/10/7/275
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 1/2] Return a value from printk_ratelimited
2014-09-19 18:15 ` Joe Perches
@ 2014-09-21 13:25 ` Paul E. McKenney
2014-09-21 15:53 ` Joe Perches
0 siblings, 1 reply; 13+ messages in thread
From: Paul E. McKenney @ 2014-09-21 13:25 UTC (permalink / raw)
To: Joe Perches
Cc: Steven Rostedt, Omar Sandoval, Chris Mason, Josef Bacik,
linux-btrfs, Josh Triplett, Mathieu Desnoyers, Lai Jiangshan,
linux-kernel
On Fri, Sep 19, 2014 at 11:15:53AM -0700, Joe Perches wrote:
> On Fri, 2014-09-19 at 13:21 -0400, Steven Rostedt wrote:
> > On Fri, 19 Sep 2014 02:01:29 -0700
> > Omar Sandoval <osandov@osandov.com> wrote:
> >
> > > printk returns an integer; there's no reason for printk_ratelimited to swallow
> > > it.
>
> Except for the lack of usefulness of the return value itself.
> See: https://lkml.org/lkml/2009/10/7/275
When printk()'s return value is changed to void, then yes, we should
clearly change this code to match that.
So, I have to ask... What happened to the patch later in that series
that was to remove the uses of the printk() return value?
Thanx, Paul
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 0/2] Move BTRFS RCU string to common library
2014-09-19 16:22 ` Chris Mason
@ 2014-09-21 13:25 ` Paul E. McKenney
0 siblings, 0 replies; 13+ messages in thread
From: Paul E. McKenney @ 2014-09-21 13:25 UTC (permalink / raw)
To: Chris Mason
Cc: Omar Sandoval, Josef Bacik, linux-btrfs, Josh Triplett,
Steven Rostedt, Mathieu Desnoyers, Lai Jiangshan, linux-kernel
On Fri, Sep 19, 2014 at 12:22:57PM -0400, Chris Mason wrote:
> On 09/19/2014 12:05 PM, Paul E. McKenney wrote:
> > On Fri, Sep 19, 2014 at 11:47:53AM -0400, Chris Mason wrote:
> >>
> >>
> >> On 09/19/2014 11:45 AM, Paul E. McKenney wrote:
> >>> On Fri, Sep 19, 2014 at 02:01:28AM -0700, Omar Sandoval wrote:
> >>>> This patch series moves the generic RCU string library used internally by BTRFS
> >>>> to be accessible by anyone. It provides printk_in_rcu and
> >>>> printk_ratelimited_in_rcu to print these strings. In order to avoid a weird
> >>>> inconsistency between the two, the first patch fixes printk_ratelimited so it
> >>>> passes on the return value from printk.
> >>>>
> >>>> The second patch actually moves the RCU string library. Version 2 passes on the
> >>>> return values from printk{,_ratelimited} and fixes some style issues.
> >>>>
> >>>> Omar Sandoval (2):
> >>>
> >>> For the series:
> >>>
> >>> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> >>
> >> Fine by me too, Paul, do you want to merge it in?
> >
> > I would be happy to.
> >
> > Are you thinking in terms of 3.18 or 3.19? These look OK either way, but
> > thought I should check.
>
> Either way is fine with me. Actually this will have minor conflicts
> with my current branch headed for-next, so I can resolve and send as a
> stand alone pull.
There are no conflicts with RCU, just adding a file, so I am just as
happy to have you send this via your tree.
Thanx, Paul
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 1/2] Return a value from printk_ratelimited
2014-09-21 13:25 ` Paul E. McKenney
@ 2014-09-21 15:53 ` Joe Perches
0 siblings, 0 replies; 13+ messages in thread
From: Joe Perches @ 2014-09-21 15:53 UTC (permalink / raw)
To: paulmck, Alan Jenkins
Cc: Steven Rostedt, Omar Sandoval, Chris Mason, Josef Bacik,
linux-btrfs, Josh Triplett, Mathieu Desnoyers, Lai Jiangshan,
linux-kernel
On Sun, 2014-09-21 at 06:25 -0700, Paul E. McKenney wrote:
> On Fri, Sep 19, 2014 at 11:15:53AM -0700, Joe Perches wrote:
> > On Fri, 2014-09-19 at 13:21 -0400, Steven Rostedt wrote:
> > > On Fri, 19 Sep 2014 02:01:29 -0700
> > > Omar Sandoval <osandov@osandov.com> wrote:
> > >
> > > > printk returns an integer; there's no reason for printk_ratelimited to swallow
> > > > it.
> >
> > Except for the lack of usefulness of the return value itself.
> > See: https://lkml.org/lkml/2009/10/7/275
>
> When printk()'s return value is changed to void, then yes, we should
> clearly change this code to match that.
>
> So, I have to ask... What happened to the patch later in that series
> that was to remove the uses of the printk() return value?
I don't know.
Last I recall via searching emails, Alan Jenkins was going to do
something with it. (I've added his old email to this reply, but
I doubt still works)
I remember checking whether or not the removing the return value
reduced the code size on x86 (it did not), and forgot about it.
I don't know if removing the printk return value reduces overall
image size in any arch, so I didn't pursue it.
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v2 2/2] Move BTRFS RCU string to common library
2014-09-19 9:01 ` [PATCH v2 2/2] Move BTRFS RCU string to common library Omar Sandoval
@ 2014-09-26 23:25 ` josh
0 siblings, 0 replies; 13+ messages in thread
From: josh @ 2014-09-26 23:25 UTC (permalink / raw)
To: Omar Sandoval
Cc: Chris Mason, Josef Bacik, linux-btrfs, Paul E. McKenney,
Steven Rostedt, Mathieu Desnoyers, Lai Jiangshan, linux-kernel
On Fri, Sep 19, 2014 at 02:01:30AM -0700, Omar Sandoval wrote:
> The RCU-friendy string API used internally by BTRFS is generic enough for
> common use. This doesn't add any new functionality, but instead just moves the
> code and documents the existing API.
>
> Signed-off-by: Omar Sandoval <osandov@osandov.com>
One nit: shouldn't the returned rcu_string pointer have an __rcu
address space annotation?
With that fixed:
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
> fs/btrfs/check-integrity.c | 6 +--
> fs/btrfs/dev-replace.c | 19 +++++-----
> fs/btrfs/disk-io.c | 6 +--
> fs/btrfs/extent_io.c | 4 +-
> fs/btrfs/ioctl.c | 4 +-
> fs/btrfs/raid56.c | 2 +-
> fs/btrfs/rcu-string.h | 56 ----------------------------
> fs/btrfs/scrub.c | 15 ++++----
> fs/btrfs/super.c | 2 +-
> fs/btrfs/volumes.c | 14 +++----
> include/linux/rcustring.h | 91 ++++++++++++++++++++++++++++++++++++++++++++++
> 11 files changed, 128 insertions(+), 91 deletions(-)
> delete mode 100644 fs/btrfs/rcu-string.h
> create mode 100644 include/linux/rcustring.h
>
> diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
> index ce92ae3..4ccd7da 100644
> --- a/fs/btrfs/check-integrity.c
> +++ b/fs/btrfs/check-integrity.c
> @@ -94,6 +94,7 @@
> #include <linux/mutex.h>
> #include <linux/genhd.h>
> #include <linux/blkdev.h>
> +#include <linux/rcustring.h>
> #include "ctree.h"
> #include "disk-io.h"
> #include "hash.h"
> @@ -103,7 +104,6 @@
> #include "print-tree.h"
> #include "locking.h"
> #include "check-integrity.h"
> -#include "rcu-string.h"
>
> #define BTRFSIC_BLOCK_HASHTABLE_SIZE 0x10000
> #define BTRFSIC_BLOCK_LINK_HASHTABLE_SIZE 0x10000
> @@ -851,8 +851,8 @@ static int btrfsic_process_superblock_dev_mirror(
> printk_in_rcu(KERN_INFO "New initial S-block (bdev %p, %s)"
> " @%llu (%s/%llu/%d)\n",
> superblock_bdev,
> - rcu_str_deref(device->name), dev_bytenr,
> - dev_state->name, dev_bytenr,
> + rcu_string_dereference(device->name),
> + dev_bytenr, dev_state->name, dev_bytenr,
> superblock_mirror_num);
> list_add(&superblock_tmp->all_blocks_node,
> &state->all_blocks_list);
> diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
> index eea26e1..87d10cc 100644
> --- a/fs/btrfs/dev-replace.c
> +++ b/fs/btrfs/dev-replace.c
> @@ -25,6 +25,7 @@
> #include <linux/capability.h>
> #include <linux/kthread.h>
> #include <linux/math64.h>
> +#include <linux/rcustring.h>
> #include <asm/div64.h>
> #include "ctree.h"
> #include "extent_map.h"
> @@ -34,7 +35,6 @@
> #include "volumes.h"
> #include "async-thread.h"
> #include "check-integrity.h"
> -#include "rcu-string.h"
> #include "dev-replace.h"
> #include "sysfs.h"
>
> @@ -376,9 +376,9 @@ int btrfs_dev_replace_start(struct btrfs_root *root,
> printk_in_rcu(KERN_INFO
> "BTRFS: dev_replace from %s (devid %llu) to %s started\n",
> src_device->missing ? "<missing disk>" :
> - rcu_str_deref(src_device->name),
> + rcu_string_dereference(src_device->name),
> src_device->devid,
> - rcu_str_deref(tgt_device->name));
> + rcu_string_dereference(tgt_device->name));
>
> tgt_device->total_bytes = src_device->total_bytes;
> tgt_device->disk_total_bytes = src_device->disk_total_bytes;
> @@ -528,9 +528,10 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
> printk_in_rcu(KERN_ERR
> "BTRFS: btrfs_scrub_dev(%s, %llu, %s) failed %d\n",
> src_device->missing ? "<missing disk>" :
> - rcu_str_deref(src_device->name),
> + rcu_string_dereference(src_device->name),
> src_device->devid,
> - rcu_str_deref(tgt_device->name), scrub_ret);
> + rcu_string_dereference(tgt_device->name),
> + scrub_ret);
> btrfs_dev_replace_unlock(dev_replace);
> mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
> mutex_unlock(&root->fs_info->chunk_mutex);
> @@ -544,9 +545,9 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info,
> printk_in_rcu(KERN_INFO
> "BTRFS: dev_replace from %s (devid %llu) to %s) finished\n",
> src_device->missing ? "<missing disk>" :
> - rcu_str_deref(src_device->name),
> + rcu_string_dereference(src_device->name),
> src_device->devid,
> - rcu_str_deref(tgt_device->name));
> + rcu_string_dereference(tgt_device->name));
> tgt_device->is_tgtdev_for_dev_replace = 0;
> tgt_device->devid = src_device->devid;
> src_device->devid = BTRFS_DEV_REPLACE_DEVID;
> @@ -805,10 +806,10 @@ static int btrfs_dev_replace_kthread(void *data)
> printk_in_rcu(KERN_INFO
> "BTRFS: continuing dev_replace from %s (devid %llu) to %s @%u%%\n",
> dev_replace->srcdev->missing ? "<missing disk>" :
> - rcu_str_deref(dev_replace->srcdev->name),
> + rcu_string_dereference(dev_replace->srcdev->name),
> dev_replace->srcdev->devid,
> dev_replace->tgtdev ?
> - rcu_str_deref(dev_replace->tgtdev->name) :
> + rcu_string_dereference(dev_replace->tgtdev->name) :
> "<missing target disk>",
> (unsigned int)progress);
> }
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index a1d36e6..00f7441 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -31,6 +31,7 @@
> #include <linux/ratelimit.h>
> #include <linux/uuid.h>
> #include <linux/semaphore.h>
> +#include <linux/rcustring.h>
> #include <asm/unaligned.h>
> #include "ctree.h"
> #include "disk-io.h"
> @@ -44,7 +45,6 @@
> #include "free-space-cache.h"
> #include "inode-map.h"
> #include "check-integrity.h"
> -#include "rcu-string.h"
> #include "dev-replace.h"
> #include "raid56.h"
> #include "sysfs.h"
> @@ -3059,7 +3059,7 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
>
> printk_ratelimited_in_rcu(KERN_WARNING "BTRFS: lost page write due to "
> "I/O error on %s\n",
> - rcu_str_deref(device->name));
> + rcu_string_dereference(device->name));
> /* note, we dont' set_buffer_write_io_error because we have
> * our own ways of dealing with the IO errors
> */
> @@ -3247,7 +3247,7 @@ static int write_dev_flush(struct btrfs_device *device, int wait)
>
> if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
> printk_in_rcu("BTRFS: disabling barriers on dev %s\n",
> - rcu_str_deref(device->name));
> + rcu_string_dereference(device->name));
> device->nobarriers = 1;
> } else if (!bio_flagged(bio, BIO_UPTODATE)) {
> ret = -EIO;
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index af0359d..441dccd 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -11,6 +11,7 @@
> #include <linux/pagevec.h>
> #include <linux/prefetch.h>
> #include <linux/cleancache.h>
> +#include <linux/rcustring.h>
> #include "extent_io.h"
> #include "extent_map.h"
> #include "ctree.h"
> @@ -18,7 +19,6 @@
> #include "volumes.h"
> #include "check-integrity.h"
> #include "locking.h"
> -#include "rcu-string.h"
> #include "backref.h"
>
> static struct kmem_cache *extent_state_cache;
> @@ -2065,7 +2065,7 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64 start,
> printk_ratelimited_in_rcu(KERN_INFO
> "BTRFS: read error corrected: ino %lu off %llu "
> "(dev %s sector %llu)\n", page->mapping->host->i_ino,
> - start, rcu_str_deref(dev->name), sector);
> + start, rcu_string_dereference(dev->name), sector);
>
> bio_put(bio);
> return 0;
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 8a8e298..9d4cd72 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -44,6 +44,7 @@
> #include <linux/uuid.h>
> #include <linux/btrfs.h>
> #include <linux/uaccess.h>
> +#include <linux/rcustring.h>
> #include "ctree.h"
> #include "disk-io.h"
> #include "transaction.h"
> @@ -53,7 +54,6 @@
> #include "locking.h"
> #include "inode-map.h"
> #include "backref.h"
> -#include "rcu-string.h"
> #include "send.h"
> #include "dev-replace.h"
> #include "props.h"
> @@ -1583,7 +1583,7 @@ static noinline int btrfs_ioctl_resize(struct file *file,
> new_size *= root->sectorsize;
>
> printk_in_rcu(KERN_INFO "BTRFS: new size for %s is %llu\n",
> - rcu_str_deref(device->name), new_size);
> + rcu_string_dereference(device->name), new_size);
>
> if (new_size > old_size) {
> trans = btrfs_start_transaction(root, 0);
> diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
> index 0a6b6e4..eecf738 100644
> --- a/fs/btrfs/raid56.c
> +++ b/fs/btrfs/raid56.c
> @@ -32,6 +32,7 @@
> #include <linux/list_sort.h>
> #include <linux/raid/xor.h>
> #include <linux/vmalloc.h>
> +#include <linux/rcustring.h>
> #include <asm/div64.h>
> #include "ctree.h"
> #include "extent_map.h"
> @@ -42,7 +43,6 @@
> #include "raid56.h"
> #include "async-thread.h"
> #include "check-integrity.h"
> -#include "rcu-string.h"
>
> /* set when additional merges to this rbio are not allowed */
> #define RBIO_RMW_LOCKED_BIT 1
> diff --git a/fs/btrfs/rcu-string.h b/fs/btrfs/rcu-string.h
> deleted file mode 100644
> index 9e111e4..0000000
> --- a/fs/btrfs/rcu-string.h
> +++ /dev/null
> @@ -1,56 +0,0 @@
> -/*
> - * Copyright (C) 2012 Red Hat. All rights reserved.
> - *
> - * This program is free software; you can redistribute it and/or
> - * modify it under the terms of the GNU General Public
> - * License v2 as published by the Free Software Foundation.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - * General Public License for more details.
> - *
> - * You should have received a copy of the GNU General Public
> - * License along with this program; if not, write to the
> - * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
> - * Boston, MA 021110-1307, USA.
> - */
> -
> -struct rcu_string {
> - struct rcu_head rcu;
> - char str[0];
> -};
> -
> -static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t mask)
> -{
> - size_t len = strlen(src) + 1;
> - struct rcu_string *ret = kzalloc(sizeof(struct rcu_string) +
> - (len * sizeof(char)), mask);
> - if (!ret)
> - return ret;
> - strncpy(ret->str, src, len);
> - return ret;
> -}
> -
> -static inline void rcu_string_free(struct rcu_string *str)
> -{
> - if (str)
> - kfree_rcu(str, rcu);
> -}
> -
> -#define printk_in_rcu(fmt, ...) do { \
> - rcu_read_lock(); \
> - printk(fmt, __VA_ARGS__); \
> - rcu_read_unlock(); \
> -} while (0)
> -
> -#define printk_ratelimited_in_rcu(fmt, ...) do { \
> - rcu_read_lock(); \
> - printk_ratelimited(fmt, __VA_ARGS__); \
> - rcu_read_unlock(); \
> -} while (0)
> -
> -#define rcu_str_deref(rcu_str) ({ \
> - struct rcu_string *__str = rcu_dereference(rcu_str); \
> - __str->str; \
> -})
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index f4a41f3..62e335f 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -18,6 +18,7 @@
>
> #include <linux/blkdev.h>
> #include <linux/ratelimit.h>
> +#include <linux/rcustring.h>
> #include "ctree.h"
> #include "volumes.h"
> #include "disk-io.h"
> @@ -27,7 +28,6 @@
> #include "extent_io.h"
> #include "dev-replace.h"
> #include "check-integrity.h"
> -#include "rcu-string.h"
> #include "raid56.h"
>
> /*
> @@ -519,7 +519,8 @@ static int scrub_print_warning_inode(u64 inum, u64 offset, u64 root,
> printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
> "%s, sector %llu, root %llu, inode %llu, offset %llu, "
> "length %llu, links %u (path: %s)\n", swarn->errstr,
> - swarn->logical, rcu_str_deref(swarn->dev->name),
> + swarn->logical,
> + rcu_string_dereference(swarn->dev->name),
> (unsigned long long)swarn->sector, root, inum, offset,
> min(isize - offset, (u64)PAGE_SIZE), nlink,
> (char *)(unsigned long)ipath->fspath->val[i]);
> @@ -531,7 +532,7 @@ err:
> printk_in_rcu(KERN_WARNING "BTRFS: %s at logical %llu on dev "
> "%s, sector %llu, root %llu, inode %llu, offset %llu: path "
> "resolving failed with ret=%d\n", swarn->errstr,
> - swarn->logical, rcu_str_deref(swarn->dev->name),
> + swarn->logical, rcu_string_dereference(swarn->dev->name),
> (unsigned long long)swarn->sector, root, inum, offset, ret);
>
> free_ipath(ipath);
> @@ -595,7 +596,7 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
> "BTRFS: %s at logical %llu on dev %s, "
> "sector %llu: metadata %s (level %d) in tree "
> "%llu\n", errstr, swarn.logical,
> - rcu_str_deref(dev->name),
> + rcu_string_dereference(dev->name),
> (unsigned long long)swarn.sector,
> ref_level ? "node" : "leaf",
> ret < 0 ? -1 : ref_level,
> @@ -796,7 +797,7 @@ out:
> num_uncorrectable_read_errors);
> printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
> "unable to fixup (nodatasum) error at logical %llu on dev %s\n",
> - fixup->logical, rcu_str_deref(fixup->dev->name));
> + fixup->logical, rcu_string_dereference(fixup->dev->name));
> }
>
> btrfs_free_path(path);
> @@ -1198,7 +1199,7 @@ corrected_error:
> spin_unlock(&sctx->stat_lock);
> printk_ratelimited_in_rcu(KERN_ERR
> "BTRFS: fixed up error at logical %llu on dev %s\n",
> - logical, rcu_str_deref(dev->name));
> + logical, rcu_string_dereference(dev->name));
> }
> } else {
> did_not_correct_error:
> @@ -1207,7 +1208,7 @@ did_not_correct_error:
> spin_unlock(&sctx->stat_lock);
> printk_ratelimited_in_rcu(KERN_ERR
> "BTRFS: unable to fixup (regular) error at logical %llu on dev %s\n",
> - logical, rcu_str_deref(dev->name));
> + logical, rcu_string_dereference(dev->name));
> }
>
> out:
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index c4124de..cf4db62 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -42,6 +42,7 @@
> #include <linux/cleancache.h>
> #include <linux/ratelimit.h>
> #include <linux/btrfs.h>
> +#include <linux/rcustring.h>
> #include "delayed-inode.h"
> #include "ctree.h"
> #include "disk-io.h"
> @@ -54,7 +55,6 @@
> #include "volumes.h"
> #include "export.h"
> #include "compression.h"
> -#include "rcu-string.h"
> #include "dev-replace.h"
> #include "free-space-cache.h"
> #include "backref.h"
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 340a92d..8b1e5e8 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -27,6 +27,7 @@
> #include <linux/kthread.h>
> #include <linux/raid/pq.h>
> #include <linux/semaphore.h>
> +#include <linux/rcustring.h>
> #include <asm/div64.h>
> #include "ctree.h"
> #include "extent_map.h"
> @@ -37,7 +38,6 @@
> #include "raid56.h"
> #include "async-thread.h"
> #include "check-integrity.h"
> -#include "rcu-string.h"
> #include "math.h"
> #include "dev-replace.h"
> #include "sysfs.h"
> @@ -6323,7 +6323,7 @@ static int update_dev_stat_item(struct btrfs_trans_handle *trans,
> if (ret < 0) {
> printk_in_rcu(KERN_WARNING "BTRFS: "
> "error %d while searching for dev_stats item for device %s!\n",
> - ret, rcu_str_deref(device->name));
> + ret, rcu_string_dereference(device->name));
> goto out;
> }
>
> @@ -6334,7 +6334,7 @@ static int update_dev_stat_item(struct btrfs_trans_handle *trans,
> if (ret != 0) {
> printk_in_rcu(KERN_WARNING "BTRFS: "
> "delete too small dev_stats item for device %s failed %d!\n",
> - rcu_str_deref(device->name), ret);
> + rcu_string_dereference(device->name), ret);
> goto out;
> }
> ret = 1;
> @@ -6347,8 +6347,8 @@ static int update_dev_stat_item(struct btrfs_trans_handle *trans,
> &key, sizeof(*ptr));
> if (ret < 0) {
> printk_in_rcu(KERN_WARNING "BTRFS: "
> - "insert dev_stats item for device %s failed %d!\n",
> - rcu_str_deref(device->name), ret);
> + "insert dev_stats item for device %s failed %d!\n",
> + rcu_string_dereference(device->name), ret);
> goto out;
> }
> }
> @@ -6402,7 +6402,7 @@ static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
> return;
> printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
> "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
> - rcu_str_deref(dev->name),
> + rcu_string_dereference(dev->name),
> btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
> btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
> btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
> @@ -6422,7 +6422,7 @@ static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
>
> printk_in_rcu(KERN_INFO "BTRFS: "
> "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
> - rcu_str_deref(dev->name),
> + rcu_string_dereference(dev->name),
> btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
> btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
> btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
> diff --git a/include/linux/rcustring.h b/include/linux/rcustring.h
> new file mode 100644
> index 0000000..18980e9
> --- /dev/null
> +++ b/include/linux/rcustring.h
> @@ -0,0 +1,91 @@
> +/*
> + * RCU-friendly strings
> + *
> + * Copyright (C) 2012 Red Hat. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, you can access it online at
> + * http://www.gnu.org/licenses/gpl-2.0.html.
> + */
> +
> +#ifndef _LINUX_RCUSTRING_H
> +#define _LINUX_RCUSTRING_H
> +
> +struct rcu_string {
> + struct rcu_head rcu;
> + char str[0];
> +};
> +
> +/**
> + * rcu_string_strdup() - create an RCU string from a string
> + * @src: The string to copy
> + * @flags: Flags for kmalloc
> + */
> +static inline struct rcu_string *rcu_string_strdup(const char *src, gfp_t flags)
> +{
> + struct rcu_string *ret;
> + size_t len = strlen(src) + 1;
> +
> + ret = kmalloc(sizeof(struct rcu_string) + (len * sizeof(char)), flags);
> + if (!ret)
> + return ret;
> + memcpy(ret->str, src, len);
> + return ret;
> +}
> +
> +/**
> + * rcu_string_free() - free an RCU string
> + * @str: The string
> + */
> +static inline void rcu_string_free(struct rcu_string *str)
> +{
> + if (str)
> + kfree_rcu(str, rcu);
> +}
> +
> +/*
> + * rcu_string_dereference() - dereference an RCU string
> + * @str: The string
> + *
> + * Like rcu_dereference, this must be done in an RCU critical section.
> + */
> +static inline char *rcu_string_dereference(struct rcu_string *rcu_str)
> +{
> + return rcu_dereference(rcu_str)->str;
> +}
> +
> +/**
> + * printk_in_rcu() - printk in an RCU read-side critical section
> + */
> +#define printk_in_rcu(fmt, ...) \
> +({ \
> + int __ret; \
> + rcu_read_lock(); \
> + __ret = printk(fmt, __VA_ARGS__); \
> + rcu_read_unlock(); \
> + __ret; \
> +})
> +
> +/**
> + * printk_ratelimited_in_rcu() - printk in an RCU read-side critical section
> + */
> +#define printk_ratelimited_in_rcu(fmt, ...) \
> +({ \
> + int __ret; \
> + rcu_read_lock(); \
> + __ret = printk_ratelimited(fmt, __VA_ARGS__); \
> + rcu_read_unlock(); \
> + __ret; \
> +})
> +
> +#endif
> --
> 2.1.0
>
^ permalink raw reply [flat|nested] 13+ messages in thread
end of thread, other threads:[~2014-09-26 23:25 UTC | newest]
Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-09-19 9:01 [PATCH v2 0/2] Move BTRFS RCU string to common library Omar Sandoval
2014-09-19 9:01 ` [PATCH v2 1/2] Return a value from printk_ratelimited Omar Sandoval
2014-09-19 17:21 ` Steven Rostedt
2014-09-19 18:15 ` Joe Perches
2014-09-21 13:25 ` Paul E. McKenney
2014-09-21 15:53 ` Joe Perches
2014-09-19 9:01 ` [PATCH v2 2/2] Move BTRFS RCU string to common library Omar Sandoval
2014-09-26 23:25 ` josh
2014-09-19 15:45 ` [PATCH v2 0/2] " Paul E. McKenney
2014-09-19 15:47 ` Chris Mason
2014-09-19 16:05 ` Paul E. McKenney
2014-09-19 16:22 ` Chris Mason
2014-09-21 13:25 ` Paul E. McKenney
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