From 77304d2abac6101f7249754ffdd4421258877ab0 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 8 Nov 2010 14:39:12 +0100 Subject: 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 Acked-by: NeilBrown Acked-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/md/md.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/md.c b/drivers/md/md.c index 4e957f3140a..324a3663fcd 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", @@ -5235,8 +5235,8 @@ 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; - } else + 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; -- cgit v1.2.3