| Message ID | 81ca3d5eb14b7fe1a5caa5ede5f882c39d93b5b4.1412355922.git.osandov@osandov.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 03, 2014 at 10:12:38AM -0700, Omar Sandoval wrote: > The RCU-friendly 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> > Reviewed-by: Josh Triplett <josh@joshtriplett.org> > Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > --- > Version 4 doesn't return anything from the printk wrappers on the assumption > that printk will return void someday (possibly soon). This is a resubmission > because I omitted the v4 from the subject last time so it may have gotten > buried. It applies to v3.17-rc7 and should be good to go for 3.18 or 3.19. > > 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 | 89 ++++++++++++++++++++++++++++++++++++++++++++++ > 11 files changed, 126 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 2c2d6d1..ada5f86 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" > @@ -6322,7 +6322,7 @@ 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; > } > > @@ -6333,7 +6333,7 @@ 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; > @@ -6346,8 +6346,8 @@ 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; > } > } > @@ -6401,7 +6401,7 @@ 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), > @@ -6421,7 +6421,7 @@ 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..5744e85 > --- /dev/null > +++ b/include/linux/rcustring.h > @@ -0,0 +1,89 @@ > +/* > + * 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 *rcu_string_strdup(const char *src, > + gfp_t flags) > +{ > + struct rcu_string *ret; > + size_t len = strlen(src) + 1; > + > + ret = kmalloc(sizeof(*ret) + (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 __rcu *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 *rcu_str) > +{ > + return rcu_dereference(rcu_str)->str; > +} > + > +/** > + * printk_in_rcu() - printk in an RCU read-side critical section > + */ > +#define printk_in_rcu(fmt, ...) \ > + do { \ > + rcu_read_lock(); \ > + printk(fmt, __VA_ARGS__); \ > + rcu_read_unlock(); \ > + } while (0) > + > +/** > + * printk_ratelimited_in_rcu() - printk_ratelimited in an RCU read-side critical > + * section > + */ > +#define printk_ratelimited_in_rcu(fmt, ...) \ > + do { \ > + rcu_read_lock(); \ > + printk_ratelimited(fmt, __VA_ARGS__); \ > + rcu_read_unlock(); \ > + } while (0) > + > +#endif > -- > 2.1.2 > Hi, Just pinging this patch to check up on it. It applies cleanly to 3.17 but not to 3.18-rc1; if everything looks good otherwise, I can regenerate this patch against 3.18-rc1 for applying if that'd make things easier. Thanks!
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 2c2d6d1..ada5f86 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" @@ -6322,7 +6322,7 @@ 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; } @@ -6333,7 +6333,7 @@ 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; @@ -6346,8 +6346,8 @@ 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; } } @@ -6401,7 +6401,7 @@ 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), @@ -6421,7 +6421,7 @@ 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..5744e85 --- /dev/null +++ b/include/linux/rcustring.h @@ -0,0 +1,89 @@ +/* + * 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 *rcu_string_strdup(const char *src, + gfp_t flags) +{ + struct rcu_string *ret; + size_t len = strlen(src) + 1; + + ret = kmalloc(sizeof(*ret) + (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 __rcu *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 *rcu_str) +{ + return rcu_dereference(rcu_str)->str; +} + +/** + * printk_in_rcu() - printk in an RCU read-side critical section + */ +#define printk_in_rcu(fmt, ...) \ + do { \ + rcu_read_lock(); \ + printk(fmt, __VA_ARGS__); \ + rcu_read_unlock(); \ + } while (0) + +/** + * printk_ratelimited_in_rcu() - printk_ratelimited in an RCU read-side critical + * section + */ +#define printk_ratelimited_in_rcu(fmt, ...) \ + do { \ + rcu_read_lock(); \ + printk_ratelimited(fmt, __VA_ARGS__); \ + rcu_read_unlock(); \ + } while (0) + +#endif