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Message-Id: <1288985241-3515-1-git-send-email-snitzer@redhat.com>
Date: Fri, 5 Nov 2010 15:27:21 -0400
From: Mike Snitzer <snitzer@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: linux-fsdevel@...r.kernel.org, Jens Axboe <jaxboe@...ionio.com>,
Neil Brown <neilb@...e.de>, drbd-dev@...ts.linbit.com
Subject: [PATCH] block: read i_size with i_size_read()
Convert direct reads of an inode's i_size to using i_size_read().
i_size_{read,write} use a seqcount to protect reads from accessing
incomple writes. Concurrent i_size_write()s require mutual exclussion
to protect the seqcount that is used by i_size_{read,write}. But
i_size_read() callers do not need to use additional locking.
Signed-off-by: Mike Snitzer <snitzer@...hat.com>
Cc: Jens Axboe <jaxboe@...ionio.com>
Cc: Neil Brown <neilb@...e.de>
Cc: drbd-dev@...ts.linbit.com
---
block/blk-core.c | 4 ++--
block/compat_ioctl.c | 4 ++--
block/ioctl.c | 6 +++---
drivers/block/drbd/drbd_int.h | 2 +-
drivers/md/md.c | 18 +++++++++---------
5 files changed, 17 insertions(+), 17 deletions(-)
NOTE: I stopped short of fixing drbd and nbd to use revalidate_disk
and/or i_size_write. I also have no intention of auditing all the
direct i_size readers/writers in fs/, maybe others will have an
interest.
diff --git a/block/blk-core.c b/block/blk-core.c
index f0834e2..17fcb83 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1351,7 +1351,7 @@ static void handle_bad_sector(struct bio *bio)
bdevname(bio->bi_bdev, b),
bio->bi_rw,
(unsigned long long)bio->bi_sector + bio_sectors(bio),
- (long long)(bio->bi_bdev->bd_inode->i_size >> 9));
+ (long long)(i_size_read(bio->bi_bdev->bd_inode) >> 9));
set_bit(BIO_EOF, &bio->bi_flags);
}
@@ -1404,7 +1404,7 @@ static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)
return 0;
/* Test device or partition size, when known. */
- maxsector = bio->bi_bdev->bd_inode->i_size >> 9;
+ maxsector = i_size_read(bio->bi_bdev->bd_inode) >> 9;
if (maxsector) {
sector_t sector = bio->bi_sector;
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index 119f07b..58c6ee5 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -744,13 +744,13 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
return 0;
case BLKGETSIZE:
- size = bdev->bd_inode->i_size;
+ size = i_size_read(bdev->bd_inode);
if ((size >> 9) > ~0UL)
return -EFBIG;
return compat_put_ulong(arg, size >> 9);
case BLKGETSIZE64_32:
- return compat_put_u64(arg, bdev->bd_inode->i_size);
+ return compat_put_u64(arg, i_size_read(bdev->bd_inode));
case BLKTRACESETUP32:
case BLKTRACESTART: /* compatible */
diff --git a/block/ioctl.c b/block/ioctl.c
index d724ceb..38aa194 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -125,7 +125,7 @@ static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
start >>= 9;
len >>= 9;
- if (start + len > (bdev->bd_inode->i_size >> 9))
+ if (start + len > (i_size_read(bdev->bd_inode) >> 9))
return -EINVAL;
if (secure)
flags |= BLKDEV_DISCARD_SECURE;
@@ -307,12 +307,12 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
ret = blkdev_reread_part(bdev);
break;
case BLKGETSIZE:
- size = bdev->bd_inode->i_size;
+ size = i_size_read(bdev->bd_inode);
if ((size >> 9) > ~0UL)
return -EFBIG;
return put_ulong(arg, size >> 9);
case BLKGETSIZE64:
- return put_u64(arg, bdev->bd_inode->i_size);
+ return put_u64(arg, i_size_read(bdev->bd_inode));
case BLKTRACESTART:
case BLKTRACESTOP:
case BLKTRACESETUP:
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 9bdcf43..2637f49 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1874,7 +1874,7 @@ static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev)
static inline sector_t drbd_get_capacity(struct block_device *bdev)
{
/* return bdev ? get_capacity(bdev->bd_disk) : 0; */
- return bdev ? bdev->bd_inode->i_size >> 9 : 0;
+ return bdev ? i_size_read(bdev->bd_inode) >> 9 : 0;
}
/**
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 4e957f3..02607b1 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -706,7 +706,7 @@ static struct mdk_personality *find_pers(int level, char *clevel)
/* return the offset of the super block in 512byte sectors */
static inline sector_t calc_dev_sboffset(struct block_device *bdev)
{
- sector_t num_sectors = bdev->bd_inode->i_size / 512;
+ sector_t num_sectors = i_size_read(bdev->bd_inode) / 512;
return MD_NEW_SIZE_SECTORS(num_sectors);
}
@@ -1386,7 +1386,7 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
*/
switch(minor_version) {
case 0:
- sb_start = rdev->bdev->bd_inode->i_size >> 9;
+ sb_start = i_size_read(rdev->bdev->bd_inode) >> 9;
sb_start -= 8*2;
sb_start &= ~(sector_t)(4*2-1);
break;
@@ -1472,7 +1472,7 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
ret = 0;
}
if (minor_version)
- rdev->sectors = (rdev->bdev->bd_inode->i_size >> 9) -
+ rdev->sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
le64_to_cpu(sb->data_offset);
else
rdev->sectors = rdev->sb_start;
@@ -1680,7 +1680,7 @@ super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
return 0; /* component must fit device */
if (rdev->sb_start < rdev->data_offset) {
/* minor versions 1 and 2; superblock before data */
- max_sectors = rdev->bdev->bd_inode->i_size >> 9;
+ max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
max_sectors -= rdev->data_offset;
if (!num_sectors || num_sectors > max_sectors)
num_sectors = max_sectors;
@@ -1690,7 +1690,7 @@ super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
} else {
/* minor version 0; superblock after data */
sector_t sb_start;
- sb_start = (rdev->bdev->bd_inode->i_size >> 9) - 8*2;
+ sb_start = (i_size_read(rdev->bdev->bd_inode) >> 9) - 8*2;
sb_start &= ~(sector_t)(4*2 - 1);
max_sectors = rdev->sectors + sb_start - rdev->sb_start;
if (!num_sectors || num_sectors > max_sectors)
@@ -2584,7 +2584,7 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
if (!sectors)
return -EBUSY;
} else if (!sectors)
- sectors = (rdev->bdev->bd_inode->i_size >> 9) -
+ sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
rdev->data_offset;
}
if (sectors < my_mddev->dev_sectors)
@@ -2797,7 +2797,7 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
kobject_init(&rdev->kobj, &rdev_ktype);
- size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
+ size = i_size_read(rdev->bdev->bd_inode) >> BLOCK_SIZE_BITS;
if (!size) {
printk(KERN_WARNING
"md: %s has zero or unknown size, marking faulty!\n",
@@ -5235,7 +5235,7 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
if (!mddev->persistent) {
printk(KERN_INFO "md: nonpersistent superblock ...\n");
- rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
+ rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
} else
rdev->sb_start = calc_dev_sboffset(rdev->bdev);
rdev->sectors = rdev->sb_start;
@@ -5306,7 +5306,7 @@ static int hot_add_disk(mddev_t * mddev, dev_t dev)
if (mddev->persistent)
rdev->sb_start = calc_dev_sboffset(rdev->bdev);
else
- rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
+ rdev->sb_start = i_size_read(rdev->bdev->bd_inode) / 512;
rdev->sectors = rdev->sb_start;
--
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