* [PATCH 0/2][V3] block: Support online resize of disk partitions @ 2012-02-14 20:39 Vivek Goyal 2012-02-14 20:39 ` [PATCH 1/2] block: add partition resize function to blkpg ioctl Vivek Goyal 2012-02-14 20:39 ` [PATCH 2/2] util-linux: resizepart: Utility to resize a partition Vivek Goyal 0 siblings, 2 replies; 12+ messages in thread From: Vivek Goyal @ 2012-02-14 20:39 UTC (permalink / raw) To: linux-kernel, axboe, dm-devel, kzak; +Cc: vgoyal, psusi, psusi, maxim.patlasov Hi, This is V3 of patch which adds support for online resizing of a partition. This patch is based on previously posted patches by Phillip Susi. There are two patches. Out of which one is kernel patch and other one is util-linux patch to add support of a user space utility "resizepart" to allow resizing the partition. This ioctl only resizes the partition size in kenrel and does not change the size on disk. A user needs to make sure that corresponding changes are made to disk data structures also using fdisk(or partx), if changes are to be retained across reboot. Changes since V2 ---------------- - Do not ignore the "start" parameter in RESIZE ioctl. - Change resizepart utility to parse sysfs to get to partition start. Changes since V1 ---------------- Following are changes since the version Phillip posted. - RESIZE ioctl ignores the partition "start" and does not expect user to specify one. Caller needs to just specify "device", "partition number" and "size" of new partition. - Got rid of part_nr_sects_write_begin/part_nr_sects_write_end functions and replaced these with single part_nr_sects_write(). - Some sequence counter related changes are simply lifted from i_size_write(). - Initialized part->nr_sects_seq using seqcount_init(). Phillip, do let me know if I should put your signed-off-by also in the patch. Any review feedback is welcome. I did following test. - Create a partition of 10MB on a disk using fdisk. - Add this partition to a volume group - Use fdisk to increase the partition size to 20MB. (First delete the partition and then create a new one of 20MB size). - Use resizepart to extend partition size in kernel. resizepart /dev/sdc 1 40960 - Do pvresize on partition so that physical volume can be incrased in size online. pvresize /dev/sda1 pvresize does recognize the new size. Also lsblk and /proc/partitions report the new size of partition. Thanks Vivek [PATCH 1/2] block: add partition resize function to blkpg ioctl [PATCH 2/2] util-linux: resizepart: Utility to resize a partition ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 1/2] block: add partition resize function to blkpg ioctl 2012-02-14 20:39 [PATCH 0/2][V3] block: Support online resize of disk partitions Vivek Goyal @ 2012-02-14 20:39 ` Vivek Goyal 2012-02-20 14:42 ` Vivek Goyal ` (2 more replies) 2012-02-14 20:39 ` [PATCH 2/2] util-linux: resizepart: Utility to resize a partition Vivek Goyal 1 sibling, 3 replies; 12+ messages in thread From: Vivek Goyal @ 2012-02-14 20:39 UTC (permalink / raw) To: linux-kernel, axboe, dm-devel, kzak; +Cc: vgoyal, psusi, psusi, maxim.patlasov Add a new operation code ( BLKPG_RESIZE_PARTITION ) to the BLKPG ioctl that allows altering the size of an existing partition, even if it is currently in use. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- block/genhd.c | 20 ++++++++++++---- block/ioctl.c | 57 ++++++++++++++++++++++++++++++++++++++++++-- block/partition-generic.c | 4 ++- include/linux/blkpg.h | 1 + include/linux/genhd.h | 57 +++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 130 insertions(+), 9 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 23b4f70..935e09b 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -153,7 +153,7 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) part = rcu_dereference(ptbl->part[piter->idx]); if (!part) continue; - if (!part->nr_sects && + if (!part_nr_sects_read(part) && !(piter->flags & DISK_PITER_INCL_EMPTY) && !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && piter->idx == 0)) @@ -190,7 +190,7 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit); static inline int sector_in_part(struct hd_struct *part, sector_t sector) { return part->start_sect <= sector && - sector < part->start_sect + part->nr_sects; + sector < part->start_sect + part_nr_sects_read(part); } /** @@ -765,8 +765,8 @@ void __init printk_all_partitions(void) printk("%s%s %10llu %s %s", is_part0 ? "" : " ", bdevt_str(part_devt(part), devt_buf), - (unsigned long long)part->nr_sects >> 1, - disk_name(disk, part->partno, name_buf), uuid); + (unsigned long long)part_nr_sects_read(part) >> 1 + , disk_name(disk, part->partno, name_buf), uuid); if (is_part0) { if (disk->driverfs_dev != NULL && disk->driverfs_dev->driver != NULL) @@ -857,7 +857,7 @@ static int show_partition(struct seq_file *seqf, void *v) while ((part = disk_part_iter_next(&piter))) seq_printf(seqf, "%4d %7d %10llu %s\n", MAJOR(part_devt(part)), MINOR(part_devt(part)), - (unsigned long long)part->nr_sects >> 1, + (unsigned long long)part_nr_sects_read(part) >> 1, disk_name(sgp, part->partno, buf)); disk_part_iter_exit(&piter); @@ -1263,6 +1263,16 @@ struct gendisk *alloc_disk_node(int minors, int node_id) } disk->part_tbl->part[0] = &disk->part0; + /* + * set_capacity() and get_capacity() currently don't use + * seqcounter to read/update the part0->nr_sects. Still init + * the counter as we can read the sectors in IO submission + * patch using seqence counters. + * + * TODO: Ideally set_capacity() and get_capacity() should be + * converted to make use of bd_mutex and sequence counters. + */ + seqcount_init(&disk->part0.nr_sects_seq); hd_ref_init(&disk->part0); disk->minors = minors; diff --git a/block/ioctl.c b/block/ioctl.c index ba15b2d..ddbc649 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -13,7 +13,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user { struct block_device *bdevp; struct gendisk *disk; - struct hd_struct *part; + struct hd_struct *part, *lpart; struct blkpg_ioctl_arg a; struct blkpg_partition p; struct disk_part_iter piter; @@ -36,8 +36,8 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user case BLKPG_ADD_PARTITION: start = p.start >> 9; length = p.length >> 9; - /* check for fit in a hd_struct */ - if (sizeof(sector_t) == sizeof(long) && + /* check for fit in a hd_struct */ + if (sizeof(sector_t) == sizeof(long) && sizeof(long long) > sizeof(long)) { long pstart = start, plength = length; if (pstart != start || plength != length @@ -92,6 +92,57 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user bdput(bdevp); return 0; + case BLKPG_RESIZE_PARTITION: + start = p.start >> 9; + /* new length of partition in bytes */ + length = p.length >> 9; + /* check for fit in a hd_struct */ + if (sizeof(sector_t) == sizeof(long) && + sizeof(long long) > sizeof(long)) { + long pstart = start, plength = length; + if (pstart != start || plength != length + || pstart < 0 || plength < 0) + return -EINVAL; + } + part = disk_get_part(disk, partno); + if (!part) + return -ENXIO; + bdevp = bdget(part_devt(part)); + if (!bdevp) { + disk_put_part(part); + return -ENOMEM; + } + mutex_lock(&bdevp->bd_mutex); + mutex_lock_nested(&bdev->bd_mutex, 1); + if (start != part->start_sect) { + mutex_unlock(&bdevp->bd_mutex); + mutex_unlock(&bdev->bd_mutex); + disk_put_part(part); + return -EINVAL; + } + /* overlap? */ + disk_part_iter_init(&piter, disk, + DISK_PITER_INCL_EMPTY); + while ((lpart = disk_part_iter_next(&piter))) { + if (lpart->partno != partno && + !(start + length <= lpart->start_sect || + start >= lpart->start_sect + lpart->nr_sects) + ) { + disk_part_iter_exit(&piter); + mutex_unlock(&bdevp->bd_mutex); + mutex_unlock(&bdev->bd_mutex); + disk_put_part(part); + return -EBUSY; + } + } + disk_part_iter_exit(&piter); + part_nr_sects_write(part, (sector_t)length); + i_size_write(bdevp->bd_inode, p.length); + mutex_unlock(&bdevp->bd_mutex); + mutex_unlock(&bdev->bd_mutex); + bdput(bdevp); + disk_put_part(part); + return 0; default: return -EINVAL; } diff --git a/block/partition-generic.c b/block/partition-generic.c index d06ec1c..363a6f6 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -84,7 +84,7 @@ ssize_t part_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); - return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects); + return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p)); } static ssize_t part_ro_show(struct device *dev, @@ -294,6 +294,8 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, err = -ENOMEM; goto out_free; } + + seqcount_init(&p->nr_sects_seq); pdev = part_to_dev(p); p->start_sect = start; diff --git a/include/linux/blkpg.h b/include/linux/blkpg.h index faf8a45..a851944 100644 --- a/include/linux/blkpg.h +++ b/include/linux/blkpg.h @@ -40,6 +40,7 @@ struct blkpg_ioctl_arg { /* The subfunctions (for the op field) */ #define BLKPG_ADD_PARTITION 1 #define BLKPG_DEL_PARTITION 2 +#define BLKPG_RESIZE_PARTITION 3 /* Sizes of name fields. Unused at present. */ #define BLKPG_DEVNAMELTH 64 diff --git a/include/linux/genhd.h b/include/linux/genhd.h index fe23ee7..0def3ef 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -98,7 +98,13 @@ struct partition_meta_info { struct hd_struct { sector_t start_sect; + /* + * nr_sects is protected by sequence counter. One might extend a + * partition while IO is happening to it and update of nr_sects + * can be non-atomic on 32bit machines with 64bit sector_t. + */ sector_t nr_sects; + seqcount_t nr_sects_seq; sector_t alignment_offset; unsigned int discard_alignment; struct device __dev; @@ -653,6 +659,57 @@ static inline void hd_struct_put(struct hd_struct *part) __delete_partition(part); } +/* + * Any access of part->nr_sects which is not protected by partition + * bd_mutex or gendisk bdev bd_mutex, should be done using this + * accessor function. + * + * Code written along the lines of i_size_read() and i_size_write(). + * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption + * on. + */ +static inline sector_t part_nr_sects_read(struct hd_struct *part) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) + sector_t nr_sects; + unsigned seq; + do { + seq = read_seqcount_begin(&part->nr_sects_seq); + nr_sects = part->nr_sects; + } while (read_seqcount_retry(&part->nr_sects_seq, seq)); + return nr_sects; +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) + sector_t nr_sects; + + preempt_disable(); + nr_sects = part->nr_sects; + preempt_enable(); + return nr_sects; +#else + return part->nr_sects; +#endif +} + +/* + * Should be called with mutex lock held (typically bd_mutex) of partition + * to provide mutual exlusion among writers otherwise seqcount might be + * left in wrong state leaving the readers spinning infinitely. + */ +static inline void part_nr_sects_write(struct hd_struct *part, sector_t size) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) + write_seqcount_begin(&part->nr_sects_seq); + part->nr_sects = size; + write_seqcount_end(&part->nr_sects_seq); +#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT) + preempt_disable(); + part->nr_sects = size; + preempt_enable(); +#else + part->nr_sects = size; +#endif +} + #else /* CONFIG_BLOCK */ static inline void printk_all_partitions(void) { } -- 1.7.6.4 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH 1/2] block: add partition resize function to blkpg ioctl 2012-02-14 20:39 ` [PATCH 1/2] block: add partition resize function to blkpg ioctl Vivek Goyal @ 2012-02-20 14:42 ` Vivek Goyal 2012-02-20 15:17 ` Phillip Susi 2012-02-20 15:28 ` Vivek Goyal 2012-04-09 16:40 ` Maxim V. Patlasov 2 siblings, 1 reply; 12+ messages in thread From: Vivek Goyal @ 2012-02-20 14:42 UTC (permalink / raw) To: psusi, psusi; +Cc: maxim.patlasov, linux-kernel, axboe, dm-devel, kzak On Tue, Feb 14, 2012 at 03:39:50PM -0500, Vivek Goyal wrote: > Add a new operation code ( BLKPG_RESIZE_PARTITION ) to the > BLKPG ioctl that allows altering the size of an existing > partition, even if it is currently in use. Hi Phillip, Are you ok with the change? Thanks Vivek > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > --- > block/genhd.c | 20 ++++++++++++---- > block/ioctl.c | 57 ++++++++++++++++++++++++++++++++++++++++++-- > block/partition-generic.c | 4 ++- > include/linux/blkpg.h | 1 + > include/linux/genhd.h | 57 +++++++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 130 insertions(+), 9 deletions(-) > > diff --git a/block/genhd.c b/block/genhd.c > index 23b4f70..935e09b 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -153,7 +153,7 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) > part = rcu_dereference(ptbl->part[piter->idx]); > if (!part) > continue; > - if (!part->nr_sects && > + if (!part_nr_sects_read(part) && > !(piter->flags & DISK_PITER_INCL_EMPTY) && > !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && > piter->idx == 0)) > @@ -190,7 +190,7 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit); > static inline int sector_in_part(struct hd_struct *part, sector_t sector) > { > return part->start_sect <= sector && > - sector < part->start_sect + part->nr_sects; > + sector < part->start_sect + part_nr_sects_read(part); > } > > /** > @@ -765,8 +765,8 @@ void __init printk_all_partitions(void) > > printk("%s%s %10llu %s %s", is_part0 ? "" : " ", > bdevt_str(part_devt(part), devt_buf), > - (unsigned long long)part->nr_sects >> 1, > - disk_name(disk, part->partno, name_buf), uuid); > + (unsigned long long)part_nr_sects_read(part) >> 1 > + , disk_name(disk, part->partno, name_buf), uuid); > if (is_part0) { > if (disk->driverfs_dev != NULL && > disk->driverfs_dev->driver != NULL) > @@ -857,7 +857,7 @@ static int show_partition(struct seq_file *seqf, void *v) > while ((part = disk_part_iter_next(&piter))) > seq_printf(seqf, "%4d %7d %10llu %s\n", > MAJOR(part_devt(part)), MINOR(part_devt(part)), > - (unsigned long long)part->nr_sects >> 1, > + (unsigned long long)part_nr_sects_read(part) >> 1, > disk_name(sgp, part->partno, buf)); > disk_part_iter_exit(&piter); > > @@ -1263,6 +1263,16 @@ struct gendisk *alloc_disk_node(int minors, int node_id) > } > disk->part_tbl->part[0] = &disk->part0; > > + /* > + * set_capacity() and get_capacity() currently don't use > + * seqcounter to read/update the part0->nr_sects. Still init > + * the counter as we can read the sectors in IO submission > + * patch using seqence counters. > + * > + * TODO: Ideally set_capacity() and get_capacity() should be > + * converted to make use of bd_mutex and sequence counters. > + */ > + seqcount_init(&disk->part0.nr_sects_seq); > hd_ref_init(&disk->part0); > > disk->minors = minors; > diff --git a/block/ioctl.c b/block/ioctl.c > index ba15b2d..ddbc649 100644 > --- a/block/ioctl.c > +++ b/block/ioctl.c > @@ -13,7 +13,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > { > struct block_device *bdevp; > struct gendisk *disk; > - struct hd_struct *part; > + struct hd_struct *part, *lpart; > struct blkpg_ioctl_arg a; > struct blkpg_partition p; > struct disk_part_iter piter; > @@ -36,8 +36,8 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > case BLKPG_ADD_PARTITION: > start = p.start >> 9; > length = p.length >> 9; > - /* check for fit in a hd_struct */ > - if (sizeof(sector_t) == sizeof(long) && > + /* check for fit in a hd_struct */ > + if (sizeof(sector_t) == sizeof(long) && > sizeof(long long) > sizeof(long)) { > long pstart = start, plength = length; > if (pstart != start || plength != length > @@ -92,6 +92,57 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > bdput(bdevp); > > return 0; > + case BLKPG_RESIZE_PARTITION: > + start = p.start >> 9; > + /* new length of partition in bytes */ > + length = p.length >> 9; > + /* check for fit in a hd_struct */ > + if (sizeof(sector_t) == sizeof(long) && > + sizeof(long long) > sizeof(long)) { > + long pstart = start, plength = length; > + if (pstart != start || plength != length > + || pstart < 0 || plength < 0) > + return -EINVAL; > + } > + part = disk_get_part(disk, partno); > + if (!part) > + return -ENXIO; > + bdevp = bdget(part_devt(part)); > + if (!bdevp) { > + disk_put_part(part); > + return -ENOMEM; > + } > + mutex_lock(&bdevp->bd_mutex); > + mutex_lock_nested(&bdev->bd_mutex, 1); > + if (start != part->start_sect) { > + mutex_unlock(&bdevp->bd_mutex); > + mutex_unlock(&bdev->bd_mutex); > + disk_put_part(part); > + return -EINVAL; > + } > + /* overlap? */ > + disk_part_iter_init(&piter, disk, > + DISK_PITER_INCL_EMPTY); > + while ((lpart = disk_part_iter_next(&piter))) { > + if (lpart->partno != partno && > + !(start + length <= lpart->start_sect || > + start >= lpart->start_sect + lpart->nr_sects) > + ) { > + disk_part_iter_exit(&piter); > + mutex_unlock(&bdevp->bd_mutex); > + mutex_unlock(&bdev->bd_mutex); > + disk_put_part(part); > + return -EBUSY; > + } > + } > + disk_part_iter_exit(&piter); > + part_nr_sects_write(part, (sector_t)length); > + i_size_write(bdevp->bd_inode, p.length); > + mutex_unlock(&bdevp->bd_mutex); > + mutex_unlock(&bdev->bd_mutex); > + bdput(bdevp); > + disk_put_part(part); > + return 0; > default: > return -EINVAL; > } > diff --git a/block/partition-generic.c b/block/partition-generic.c > index d06ec1c..363a6f6 100644 > --- a/block/partition-generic.c > +++ b/block/partition-generic.c > @@ -84,7 +84,7 @@ ssize_t part_size_show(struct device *dev, > struct device_attribute *attr, char *buf) > { > struct hd_struct *p = dev_to_part(dev); > - return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects); > + return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p)); > } > > static ssize_t part_ro_show(struct device *dev, > @@ -294,6 +294,8 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, > err = -ENOMEM; > goto out_free; > } > + > + seqcount_init(&p->nr_sects_seq); > pdev = part_to_dev(p); > > p->start_sect = start; > diff --git a/include/linux/blkpg.h b/include/linux/blkpg.h > index faf8a45..a851944 100644 > --- a/include/linux/blkpg.h > +++ b/include/linux/blkpg.h > @@ -40,6 +40,7 @@ struct blkpg_ioctl_arg { > /* The subfunctions (for the op field) */ > #define BLKPG_ADD_PARTITION 1 > #define BLKPG_DEL_PARTITION 2 > +#define BLKPG_RESIZE_PARTITION 3 > > /* Sizes of name fields. Unused at present. */ > #define BLKPG_DEVNAMELTH 64 > diff --git a/include/linux/genhd.h b/include/linux/genhd.h > index fe23ee7..0def3ef 100644 > --- a/include/linux/genhd.h > +++ b/include/linux/genhd.h > @@ -98,7 +98,13 @@ struct partition_meta_info { > > struct hd_struct { > sector_t start_sect; > + /* > + * nr_sects is protected by sequence counter. One might extend a > + * partition while IO is happening to it and update of nr_sects > + * can be non-atomic on 32bit machines with 64bit sector_t. > + */ > sector_t nr_sects; > + seqcount_t nr_sects_seq; > sector_t alignment_offset; > unsigned int discard_alignment; > struct device __dev; > @@ -653,6 +659,57 @@ static inline void hd_struct_put(struct hd_struct *part) > __delete_partition(part); > } > > +/* > + * Any access of part->nr_sects which is not protected by partition > + * bd_mutex or gendisk bdev bd_mutex, should be done using this > + * accessor function. > + * > + * Code written along the lines of i_size_read() and i_size_write(). > + * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption > + * on. > + */ > +static inline sector_t part_nr_sects_read(struct hd_struct *part) > +{ > +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) > + sector_t nr_sects; > + unsigned seq; > + do { > + seq = read_seqcount_begin(&part->nr_sects_seq); > + nr_sects = part->nr_sects; > + } while (read_seqcount_retry(&part->nr_sects_seq, seq)); > + return nr_sects; > +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) > + sector_t nr_sects; > + > + preempt_disable(); > + nr_sects = part->nr_sects; > + preempt_enable(); > + return nr_sects; > +#else > + return part->nr_sects; > +#endif > +} > + > +/* > + * Should be called with mutex lock held (typically bd_mutex) of partition > + * to provide mutual exlusion among writers otherwise seqcount might be > + * left in wrong state leaving the readers spinning infinitely. > + */ > +static inline void part_nr_sects_write(struct hd_struct *part, sector_t size) > +{ > +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) > + write_seqcount_begin(&part->nr_sects_seq); > + part->nr_sects = size; > + write_seqcount_end(&part->nr_sects_seq); > +#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT) > + preempt_disable(); > + part->nr_sects = size; > + preempt_enable(); > +#else > + part->nr_sects = size; > +#endif > +} > + > #else /* CONFIG_BLOCK */ > > static inline void printk_all_partitions(void) { } > -- > 1.7.6.4 ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/2] block: add partition resize function to blkpg ioctl 2012-02-20 14:42 ` Vivek Goyal @ 2012-02-20 15:17 ` Phillip Susi 0 siblings, 0 replies; 12+ messages in thread From: Phillip Susi @ 2012-02-20 15:17 UTC (permalink / raw) To: Vivek Goyal; +Cc: psusi, maxim.patlasov, linux-kernel, axboe, dm-devel, kzak -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2/20/2012 9:42 AM, Vivek Goyal wrote: > On Tue, Feb 14, 2012 at 03:39:50PM -0500, Vivek Goyal wrote: >> Add a new operation code ( BLKPG_RESIZE_PARTITION ) to the BLKPG >> ioctl that allows altering the size of an existing partition, >> even if it is currently in use. > > Hi Phillip, > > Are you ok with the change? Yes. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJPQmQWAAoJEJrBOlT6nu75V8YH/0khEQy1sCiDmjqaVAqJGn3R xjS7eCU6ndgGj3CHE+j4AJCTJ6cdrcaheEF/QWd3f2GxI0kQ6bBiWzxMeEXaSA57 VQOyKqoGalaWA78a3xFR1oax8ZwOAQi7LdyttdvzXUTKDXrO57cAAIHGQcLTPFiv a926d27kMulNQzXvjhBj/h8LAOeUVFIEbrGk5QxOw28gdStEv/RtMKeSvuq3e4qu /TxNT78K49HBaWuhTZJB4Mg7ttyBTQJrQr5c23oo9KLSUgd+3ZvaHF53vUsP7IMm Kbor7u648P0Xo2gaWGXPF5z4hmyhO08/1SNFKAKw0CSycpOlwjsbel/Ys57gIAY= =oTDA -----END PGP SIGNATURE----- ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/2] block: add partition resize function to blkpg ioctl 2012-02-14 20:39 ` [PATCH 1/2] block: add partition resize function to blkpg ioctl Vivek Goyal 2012-02-20 14:42 ` Vivek Goyal @ 2012-02-20 15:28 ` Vivek Goyal 2012-03-02 18:54 ` Vivek Goyal 2012-04-09 16:40 ` Maxim V. Patlasov 2 siblings, 1 reply; 12+ messages in thread From: Vivek Goyal @ 2012-02-20 15:28 UTC (permalink / raw) To: axboe; +Cc: psusi, psusi, maxim.patlasov, dm-devel, kzak, linux-kernel On Tue, Feb 14, 2012 at 03:39:50PM -0500, Vivek Goyal wrote: > Add a new operation code ( BLKPG_RESIZE_PARTITION ) to the > BLKPG ioctl that allows altering the size of an existing > partition, even if it is currently in use. > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Hi Jens, Can you please consider this patch for inclusion. One of our customer does want to be able to grow partitions without having to reboot the system. Thanks Vivek > --- > block/genhd.c | 20 ++++++++++++---- > block/ioctl.c | 57 ++++++++++++++++++++++++++++++++++++++++++-- > block/partition-generic.c | 4 ++- > include/linux/blkpg.h | 1 + > include/linux/genhd.h | 57 +++++++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 130 insertions(+), 9 deletions(-) > > diff --git a/block/genhd.c b/block/genhd.c > index 23b4f70..935e09b 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -153,7 +153,7 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) > part = rcu_dereference(ptbl->part[piter->idx]); > if (!part) > continue; > - if (!part->nr_sects && > + if (!part_nr_sects_read(part) && > !(piter->flags & DISK_PITER_INCL_EMPTY) && > !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && > piter->idx == 0)) > @@ -190,7 +190,7 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit); > static inline int sector_in_part(struct hd_struct *part, sector_t sector) > { > return part->start_sect <= sector && > - sector < part->start_sect + part->nr_sects; > + sector < part->start_sect + part_nr_sects_read(part); > } > > /** > @@ -765,8 +765,8 @@ void __init printk_all_partitions(void) > > printk("%s%s %10llu %s %s", is_part0 ? "" : " ", > bdevt_str(part_devt(part), devt_buf), > - (unsigned long long)part->nr_sects >> 1, > - disk_name(disk, part->partno, name_buf), uuid); > + (unsigned long long)part_nr_sects_read(part) >> 1 > + , disk_name(disk, part->partno, name_buf), uuid); > if (is_part0) { > if (disk->driverfs_dev != NULL && > disk->driverfs_dev->driver != NULL) > @@ -857,7 +857,7 @@ static int show_partition(struct seq_file *seqf, void *v) > while ((part = disk_part_iter_next(&piter))) > seq_printf(seqf, "%4d %7d %10llu %s\n", > MAJOR(part_devt(part)), MINOR(part_devt(part)), > - (unsigned long long)part->nr_sects >> 1, > + (unsigned long long)part_nr_sects_read(part) >> 1, > disk_name(sgp, part->partno, buf)); > disk_part_iter_exit(&piter); > > @@ -1263,6 +1263,16 @@ struct gendisk *alloc_disk_node(int minors, int node_id) > } > disk->part_tbl->part[0] = &disk->part0; > > + /* > + * set_capacity() and get_capacity() currently don't use > + * seqcounter to read/update the part0->nr_sects. Still init > + * the counter as we can read the sectors in IO submission > + * patch using seqence counters. > + * > + * TODO: Ideally set_capacity() and get_capacity() should be > + * converted to make use of bd_mutex and sequence counters. > + */ > + seqcount_init(&disk->part0.nr_sects_seq); > hd_ref_init(&disk->part0); > > disk->minors = minors; > diff --git a/block/ioctl.c b/block/ioctl.c > index ba15b2d..ddbc649 100644 > --- a/block/ioctl.c > +++ b/block/ioctl.c > @@ -13,7 +13,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > { > struct block_device *bdevp; > struct gendisk *disk; > - struct hd_struct *part; > + struct hd_struct *part, *lpart; > struct blkpg_ioctl_arg a; > struct blkpg_partition p; > struct disk_part_iter piter; > @@ -36,8 +36,8 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > case BLKPG_ADD_PARTITION: > start = p.start >> 9; > length = p.length >> 9; > - /* check for fit in a hd_struct */ > - if (sizeof(sector_t) == sizeof(long) && > + /* check for fit in a hd_struct */ > + if (sizeof(sector_t) == sizeof(long) && > sizeof(long long) > sizeof(long)) { > long pstart = start, plength = length; > if (pstart != start || plength != length > @@ -92,6 +92,57 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > bdput(bdevp); > > return 0; > + case BLKPG_RESIZE_PARTITION: > + start = p.start >> 9; > + /* new length of partition in bytes */ > + length = p.length >> 9; > + /* check for fit in a hd_struct */ > + if (sizeof(sector_t) == sizeof(long) && > + sizeof(long long) > sizeof(long)) { > + long pstart = start, plength = length; > + if (pstart != start || plength != length > + || pstart < 0 || plength < 0) > + return -EINVAL; > + } > + part = disk_get_part(disk, partno); > + if (!part) > + return -ENXIO; > + bdevp = bdget(part_devt(part)); > + if (!bdevp) { > + disk_put_part(part); > + return -ENOMEM; > + } > + mutex_lock(&bdevp->bd_mutex); > + mutex_lock_nested(&bdev->bd_mutex, 1); > + if (start != part->start_sect) { > + mutex_unlock(&bdevp->bd_mutex); > + mutex_unlock(&bdev->bd_mutex); > + disk_put_part(part); > + return -EINVAL; > + } > + /* overlap? */ > + disk_part_iter_init(&piter, disk, > + DISK_PITER_INCL_EMPTY); > + while ((lpart = disk_part_iter_next(&piter))) { > + if (lpart->partno != partno && > + !(start + length <= lpart->start_sect || > + start >= lpart->start_sect + lpart->nr_sects) > + ) { > + disk_part_iter_exit(&piter); > + mutex_unlock(&bdevp->bd_mutex); > + mutex_unlock(&bdev->bd_mutex); > + disk_put_part(part); > + return -EBUSY; > + } > + } > + disk_part_iter_exit(&piter); > + part_nr_sects_write(part, (sector_t)length); > + i_size_write(bdevp->bd_inode, p.length); > + mutex_unlock(&bdevp->bd_mutex); > + mutex_unlock(&bdev->bd_mutex); > + bdput(bdevp); > + disk_put_part(part); > + return 0; > default: > return -EINVAL; > } > diff --git a/block/partition-generic.c b/block/partition-generic.c > index d06ec1c..363a6f6 100644 > --- a/block/partition-generic.c > +++ b/block/partition-generic.c > @@ -84,7 +84,7 @@ ssize_t part_size_show(struct device *dev, > struct device_attribute *attr, char *buf) > { > struct hd_struct *p = dev_to_part(dev); > - return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects); > + return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p)); > } > > static ssize_t part_ro_show(struct device *dev, > @@ -294,6 +294,8 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, > err = -ENOMEM; > goto out_free; > } > + > + seqcount_init(&p->nr_sects_seq); > pdev = part_to_dev(p); > > p->start_sect = start; > diff --git a/include/linux/blkpg.h b/include/linux/blkpg.h > index faf8a45..a851944 100644 > --- a/include/linux/blkpg.h > +++ b/include/linux/blkpg.h > @@ -40,6 +40,7 @@ struct blkpg_ioctl_arg { > /* The subfunctions (for the op field) */ > #define BLKPG_ADD_PARTITION 1 > #define BLKPG_DEL_PARTITION 2 > +#define BLKPG_RESIZE_PARTITION 3 > > /* Sizes of name fields. Unused at present. */ > #define BLKPG_DEVNAMELTH 64 > diff --git a/include/linux/genhd.h b/include/linux/genhd.h > index fe23ee7..0def3ef 100644 > --- a/include/linux/genhd.h > +++ b/include/linux/genhd.h > @@ -98,7 +98,13 @@ struct partition_meta_info { > > struct hd_struct { > sector_t start_sect; > + /* > + * nr_sects is protected by sequence counter. One might extend a > + * partition while IO is happening to it and update of nr_sects > + * can be non-atomic on 32bit machines with 64bit sector_t. > + */ > sector_t nr_sects; > + seqcount_t nr_sects_seq; > sector_t alignment_offset; > unsigned int discard_alignment; > struct device __dev; > @@ -653,6 +659,57 @@ static inline void hd_struct_put(struct hd_struct *part) > __delete_partition(part); > } > > +/* > + * Any access of part->nr_sects which is not protected by partition > + * bd_mutex or gendisk bdev bd_mutex, should be done using this > + * accessor function. > + * > + * Code written along the lines of i_size_read() and i_size_write(). > + * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption > + * on. > + */ > +static inline sector_t part_nr_sects_read(struct hd_struct *part) > +{ > +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) > + sector_t nr_sects; > + unsigned seq; > + do { > + seq = read_seqcount_begin(&part->nr_sects_seq); > + nr_sects = part->nr_sects; > + } while (read_seqcount_retry(&part->nr_sects_seq, seq)); > + return nr_sects; > +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) > + sector_t nr_sects; > + > + preempt_disable(); > + nr_sects = part->nr_sects; > + preempt_enable(); > + return nr_sects; > +#else > + return part->nr_sects; > +#endif > +} > + > +/* > + * Should be called with mutex lock held (typically bd_mutex) of partition > + * to provide mutual exlusion among writers otherwise seqcount might be > + * left in wrong state leaving the readers spinning infinitely. > + */ > +static inline void part_nr_sects_write(struct hd_struct *part, sector_t size) > +{ > +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) > + write_seqcount_begin(&part->nr_sects_seq); > + part->nr_sects = size; > + write_seqcount_end(&part->nr_sects_seq); > +#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT) > + preempt_disable(); > + part->nr_sects = size; > + preempt_enable(); > +#else > + part->nr_sects = size; > +#endif > +} > + > #else /* CONFIG_BLOCK */ > > static inline void printk_all_partitions(void) { } > -- > 1.7.6.4 ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/2] block: add partition resize function to blkpg ioctl 2012-02-20 15:28 ` Vivek Goyal @ 2012-03-02 18:54 ` Vivek Goyal 2012-07-07 1:51 ` Phillip Susi 0 siblings, 1 reply; 12+ messages in thread From: Vivek Goyal @ 2012-03-02 18:54 UTC (permalink / raw) To: axboe; +Cc: psusi, psusi, maxim.patlasov, dm-devel, kzak, linux-kernel On Mon, Feb 20, 2012 at 10:28:49AM -0500, Vivek Goyal wrote: > On Tue, Feb 14, 2012 at 03:39:50PM -0500, Vivek Goyal wrote: > > Add a new operation code ( BLKPG_RESIZE_PARTITION ) to the > > BLKPG ioctl that allows altering the size of an existing > > partition, even if it is currently in use. > > > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > > Hi Jens, > > Can you please consider this patch for inclusion. One of our customer > does want to be able to grow partitions without having to reboot > the system. Hi Jens, Do you have concerns about this patch? If no, can you please consider merging it. Thanks Vivek > > > --- > > block/genhd.c | 20 ++++++++++++---- > > block/ioctl.c | 57 ++++++++++++++++++++++++++++++++++++++++++-- > > block/partition-generic.c | 4 ++- > > include/linux/blkpg.h | 1 + > > include/linux/genhd.h | 57 +++++++++++++++++++++++++++++++++++++++++++++ > > 5 files changed, 130 insertions(+), 9 deletions(-) > > > > diff --git a/block/genhd.c b/block/genhd.c > > index 23b4f70..935e09b 100644 > > --- a/block/genhd.c > > +++ b/block/genhd.c > > @@ -153,7 +153,7 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) > > part = rcu_dereference(ptbl->part[piter->idx]); > > if (!part) > > continue; > > - if (!part->nr_sects && > > + if (!part_nr_sects_read(part) && > > !(piter->flags & DISK_PITER_INCL_EMPTY) && > > !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && > > piter->idx == 0)) > > @@ -190,7 +190,7 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit); > > static inline int sector_in_part(struct hd_struct *part, sector_t sector) > > { > > return part->start_sect <= sector && > > - sector < part->start_sect + part->nr_sects; > > + sector < part->start_sect + part_nr_sects_read(part); > > } > > > > /** > > @@ -765,8 +765,8 @@ void __init printk_all_partitions(void) > > > > printk("%s%s %10llu %s %s", is_part0 ? "" : " ", > > bdevt_str(part_devt(part), devt_buf), > > - (unsigned long long)part->nr_sects >> 1, > > - disk_name(disk, part->partno, name_buf), uuid); > > + (unsigned long long)part_nr_sects_read(part) >> 1 > > + , disk_name(disk, part->partno, name_buf), uuid); > > if (is_part0) { > > if (disk->driverfs_dev != NULL && > > disk->driverfs_dev->driver != NULL) > > @@ -857,7 +857,7 @@ static int show_partition(struct seq_file *seqf, void *v) > > while ((part = disk_part_iter_next(&piter))) > > seq_printf(seqf, "%4d %7d %10llu %s\n", > > MAJOR(part_devt(part)), MINOR(part_devt(part)), > > - (unsigned long long)part->nr_sects >> 1, > > + (unsigned long long)part_nr_sects_read(part) >> 1, > > disk_name(sgp, part->partno, buf)); > > disk_part_iter_exit(&piter); > > > > @@ -1263,6 +1263,16 @@ struct gendisk *alloc_disk_node(int minors, int node_id) > > } > > disk->part_tbl->part[0] = &disk->part0; > > > > + /* > > + * set_capacity() and get_capacity() currently don't use > > + * seqcounter to read/update the part0->nr_sects. Still init > > + * the counter as we can read the sectors in IO submission > > + * patch using seqence counters. > > + * > > + * TODO: Ideally set_capacity() and get_capacity() should be > > + * converted to make use of bd_mutex and sequence counters. > > + */ > > + seqcount_init(&disk->part0.nr_sects_seq); > > hd_ref_init(&disk->part0); > > > > disk->minors = minors; > > diff --git a/block/ioctl.c b/block/ioctl.c > > index ba15b2d..ddbc649 100644 > > --- a/block/ioctl.c > > +++ b/block/ioctl.c > > @@ -13,7 +13,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > > { > > struct block_device *bdevp; > > struct gendisk *disk; > > - struct hd_struct *part; > > + struct hd_struct *part, *lpart; > > struct blkpg_ioctl_arg a; > > struct blkpg_partition p; > > struct disk_part_iter piter; > > @@ -36,8 +36,8 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > > case BLKPG_ADD_PARTITION: > > start = p.start >> 9; > > length = p.length >> 9; > > - /* check for fit in a hd_struct */ > > - if (sizeof(sector_t) == sizeof(long) && > > + /* check for fit in a hd_struct */ > > + if (sizeof(sector_t) == sizeof(long) && > > sizeof(long long) > sizeof(long)) { > > long pstart = start, plength = length; > > if (pstart != start || plength != length > > @@ -92,6 +92,57 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > > bdput(bdevp); > > > > return 0; > > + case BLKPG_RESIZE_PARTITION: > > + start = p.start >> 9; > > + /* new length of partition in bytes */ > > + length = p.length >> 9; > > + /* check for fit in a hd_struct */ > > + if (sizeof(sector_t) == sizeof(long) && > > + sizeof(long long) > sizeof(long)) { > > + long pstart = start, plength = length; > > + if (pstart != start || plength != length > > + || pstart < 0 || plength < 0) > > + return -EINVAL; > > + } > > + part = disk_get_part(disk, partno); > > + if (!part) > > + return -ENXIO; > > + bdevp = bdget(part_devt(part)); > > + if (!bdevp) { > > + disk_put_part(part); > > + return -ENOMEM; > > + } > > + mutex_lock(&bdevp->bd_mutex); > > + mutex_lock_nested(&bdev->bd_mutex, 1); > > + if (start != part->start_sect) { > > + mutex_unlock(&bdevp->bd_mutex); > > + mutex_unlock(&bdev->bd_mutex); > > + disk_put_part(part); > > + return -EINVAL; > > + } > > + /* overlap? */ > > + disk_part_iter_init(&piter, disk, > > + DISK_PITER_INCL_EMPTY); > > + while ((lpart = disk_part_iter_next(&piter))) { > > + if (lpart->partno != partno && > > + !(start + length <= lpart->start_sect || > > + start >= lpart->start_sect + lpart->nr_sects) > > + ) { > > + disk_part_iter_exit(&piter); > > + mutex_unlock(&bdevp->bd_mutex); > > + mutex_unlock(&bdev->bd_mutex); > > + disk_put_part(part); > > + return -EBUSY; > > + } > > + } > > + disk_part_iter_exit(&piter); > > + part_nr_sects_write(part, (sector_t)length); > > + i_size_write(bdevp->bd_inode, p.length); > > + mutex_unlock(&bdevp->bd_mutex); > > + mutex_unlock(&bdev->bd_mutex); > > + bdput(bdevp); > > + disk_put_part(part); > > + return 0; > > default: > > return -EINVAL; > > } > > diff --git a/block/partition-generic.c b/block/partition-generic.c > > index d06ec1c..363a6f6 100644 > > --- a/block/partition-generic.c > > +++ b/block/partition-generic.c > > @@ -84,7 +84,7 @@ ssize_t part_size_show(struct device *dev, > > struct device_attribute *attr, char *buf) > > { > > struct hd_struct *p = dev_to_part(dev); > > - return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects); > > + return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p)); > > } > > > > static ssize_t part_ro_show(struct device *dev, > > @@ -294,6 +294,8 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, > > err = -ENOMEM; > > goto out_free; > > } > > + > > + seqcount_init(&p->nr_sects_seq); > > pdev = part_to_dev(p); > > > > p->start_sect = start; > > diff --git a/include/linux/blkpg.h b/include/linux/blkpg.h > > index faf8a45..a851944 100644 > > --- a/include/linux/blkpg.h > > +++ b/include/linux/blkpg.h > > @@ -40,6 +40,7 @@ struct blkpg_ioctl_arg { > > /* The subfunctions (for the op field) */ > > #define BLKPG_ADD_PARTITION 1 > > #define BLKPG_DEL_PARTITION 2 > > +#define BLKPG_RESIZE_PARTITION 3 > > > > /* Sizes of name fields. Unused at present. */ > > #define BLKPG_DEVNAMELTH 64 > > diff --git a/include/linux/genhd.h b/include/linux/genhd.h > > index fe23ee7..0def3ef 100644 > > --- a/include/linux/genhd.h > > +++ b/include/linux/genhd.h > > @@ -98,7 +98,13 @@ struct partition_meta_info { > > > > struct hd_struct { > > sector_t start_sect; > > + /* > > + * nr_sects is protected by sequence counter. One might extend a > > + * partition while IO is happening to it and update of nr_sects > > + * can be non-atomic on 32bit machines with 64bit sector_t. > > + */ > > sector_t nr_sects; > > + seqcount_t nr_sects_seq; > > sector_t alignment_offset; > > unsigned int discard_alignment; > > struct device __dev; > > @@ -653,6 +659,57 @@ static inline void hd_struct_put(struct hd_struct *part) > > __delete_partition(part); > > } > > > > +/* > > + * Any access of part->nr_sects which is not protected by partition > > + * bd_mutex or gendisk bdev bd_mutex, should be done using this > > + * accessor function. > > + * > > + * Code written along the lines of i_size_read() and i_size_write(). > > + * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption > > + * on. > > + */ > > +static inline sector_t part_nr_sects_read(struct hd_struct *part) > > +{ > > +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) > > + sector_t nr_sects; > > + unsigned seq; > > + do { > > + seq = read_seqcount_begin(&part->nr_sects_seq); > > + nr_sects = part->nr_sects; > > + } while (read_seqcount_retry(&part->nr_sects_seq, seq)); > > + return nr_sects; > > +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) > > + sector_t nr_sects; > > + > > + preempt_disable(); > > + nr_sects = part->nr_sects; > > + preempt_enable(); > > + return nr_sects; > > +#else > > + return part->nr_sects; > > +#endif > > +} > > + > > +/* > > + * Should be called with mutex lock held (typically bd_mutex) of partition > > + * to provide mutual exlusion among writers otherwise seqcount might be > > + * left in wrong state leaving the readers spinning infinitely. > > + */ > > +static inline void part_nr_sects_write(struct hd_struct *part, sector_t size) > > +{ > > +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) > > + write_seqcount_begin(&part->nr_sects_seq); > > + part->nr_sects = size; > > + write_seqcount_end(&part->nr_sects_seq); > > +#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT) > > + preempt_disable(); > > + part->nr_sects = size; > > + preempt_enable(); > > +#else > > + part->nr_sects = size; > > +#endif > > +} > > + > > #else /* CONFIG_BLOCK */ > > > > static inline void printk_all_partitions(void) { } > > -- > > 1.7.6.4 ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/2] block: add partition resize function to blkpg ioctl 2012-03-02 18:54 ` Vivek Goyal @ 2012-07-07 1:51 ` Phillip Susi 2012-07-09 15:13 ` Vivek Goyal 0 siblings, 1 reply; 12+ messages in thread From: Phillip Susi @ 2012-07-07 1:51 UTC (permalink / raw) To: Vivek Goyal; +Cc: axboe, maxim.patlasov, dm-devel, kzak, linux-kernel -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 What's the status of this patch? Forgotten, or are there still any outstanding concerns? On 03/02/2012 01:54 PM, Vivek Goyal wrote: > Hi Jens, > > Do you have concerns about this patch? If no, can you please consider > merging it. > > Thanks > Vivek -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJP95YUAAoJEJrBOlT6nu75A/kIAIEWs+MlA8Me05jjBGpSFQsn VigiYTF4UdWjA3bG0CNB41eqpzOKVl/B4vTBAy1YezuUXMamBRp1OD6hatEL/blO ps/M2S2NNPgFOzDmZBgfWIib6tnbCJvTowLdt4n4NnP0DoQRn+5bXopL/jcm4lwU XWheiqFFX1xSB5YgP+GMl4zVWZhyrHYcynqK/25EimbEXtjgTyR3Cy4wMfGgMdnI HkY7D0Kn420n+X6uRLXZW8hV3apATZCz3PGsxg7FI83gFi7Tc9rneOhwgRkAXHxq FcJ2NABK83dACAYOU0fhVTmxoumxuHNCmp7iRGiavnbNCBJWxLV2x1WhceX23lc= =1FUQ -----END PGP SIGNATURE----- ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/2] block: add partition resize function to blkpg ioctl 2012-07-07 1:51 ` Phillip Susi @ 2012-07-09 15:13 ` Vivek Goyal 0 siblings, 0 replies; 12+ messages in thread From: Vivek Goyal @ 2012-07-09 15:13 UTC (permalink / raw) To: Phillip Susi; +Cc: axboe, maxim.patlasov, dm-devel, kzak, linux-kernel On Fri, Jul 06, 2012 at 09:51:16PM -0400, Phillip Susi wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > What's the status of this patch? Forgotten, or are there still any outstanding concerns? There was one outstanding concern from maxim about missing "bdput(bdevp)". Will see if I can find some time to brush it up and test patches again. If somebody can beat me to it, that would be great. Thanks Vivek > > On 03/02/2012 01:54 PM, Vivek Goyal wrote: > > Hi Jens, > > > > Do you have concerns about this patch? If no, can you please consider > > merging it. > > > > Thanks > > Vivek > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.11 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ > > iQEcBAEBAgAGBQJP95YUAAoJEJrBOlT6nu75A/kIAIEWs+MlA8Me05jjBGpSFQsn > VigiYTF4UdWjA3bG0CNB41eqpzOKVl/B4vTBAy1YezuUXMamBRp1OD6hatEL/blO > ps/M2S2NNPgFOzDmZBgfWIib6tnbCJvTowLdt4n4NnP0DoQRn+5bXopL/jcm4lwU > XWheiqFFX1xSB5YgP+GMl4zVWZhyrHYcynqK/25EimbEXtjgTyR3Cy4wMfGgMdnI > HkY7D0Kn420n+X6uRLXZW8hV3apATZCz3PGsxg7FI83gFi7Tc9rneOhwgRkAXHxq > FcJ2NABK83dACAYOU0fhVTmxoumxuHNCmp7iRGiavnbNCBJWxLV2x1WhceX23lc= > =1FUQ > -----END PGP SIGNATURE----- ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/2] block: add partition resize function to blkpg ioctl 2012-02-14 20:39 ` [PATCH 1/2] block: add partition resize function to blkpg ioctl Vivek Goyal 2012-02-20 14:42 ` Vivek Goyal 2012-02-20 15:28 ` Vivek Goyal @ 2012-04-09 16:40 ` Maxim V. Patlasov 2 siblings, 0 replies; 12+ messages in thread From: Maxim V. Patlasov @ 2012-04-09 16:40 UTC (permalink / raw) To: Vivek Goyal Cc: linux-kernel, axboe, dm-devel, kzak, psusi, psusi, maxim.patlasov Hi Vivek, See please inline comments below... On 02/15/2012 12:39 AM, Vivek Goyal wrote: > ... > @@ -765,8 +765,8 @@ void __init printk_all_partitions(void) > > printk("%s%s %10llu %s %s", is_part0 ? "" : " ", > bdevt_str(part_devt(part), devt_buf), > - (unsigned long long)part->nr_sects>> 1, > - disk_name(disk, part->partno, name_buf), uuid); > + (unsigned long long)part_nr_sects_read(part)>> 1 > + , disk_name(disk, part->partno, name_buf), uuid); A line starting from comma looks unusual. Is it what you intended? > diff --git a/block/ioctl.c b/block/ioctl.c > index ba15b2d..ddbc649 100644 > --- a/block/ioctl.c > +++ b/block/ioctl.c > ... > @@ -92,6 +92,57 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user > bdput(bdevp); > > return 0; > + case BLKPG_RESIZE_PARTITION: > + start = p.start>> 9; > + /* new length of partition in bytes */ > + length = p.length>> 9; > + /* check for fit in a hd_struct */ > + if (sizeof(sector_t) == sizeof(long)&& > + sizeof(long long)> sizeof(long)) { > + long pstart = start, plength = length; > + if (pstart != start || plength != length > + || pstart< 0 || plength< 0) > + return -EINVAL; > + } > + part = disk_get_part(disk, partno); > + if (!part) > + return -ENXIO; > + bdevp = bdget(part_devt(part)); > + if (!bdevp) { > + disk_put_part(part); > + return -ENOMEM; > + } > + mutex_lock(&bdevp->bd_mutex); > + mutex_lock_nested(&bdev->bd_mutex, 1); > + if (start != part->start_sect) { > + mutex_unlock(&bdevp->bd_mutex); > + mutex_unlock(&bdev->bd_mutex); > + disk_put_part(part); > + return -EINVAL; bdput(bdevp) missed? > + } > + /* overlap? */ > + disk_part_iter_init(&piter, disk, > + DISK_PITER_INCL_EMPTY); > + while ((lpart = disk_part_iter_next(&piter))) { > + if (lpart->partno != partno&& > + !(start + length<= lpart->start_sect || > + start>= lpart->start_sect + lpart->nr_sects) > + ) { > + disk_part_iter_exit(&piter); > + mutex_unlock(&bdevp->bd_mutex); > + mutex_unlock(&bdev->bd_mutex); > + disk_put_part(part); > + return -EBUSY; bdput(bdevp) missed? > + } > + } > + disk_part_iter_exit(&piter); > + part_nr_sects_write(part, (sector_t)length); > + i_size_write(bdevp->bd_inode, p.length); > + mutex_unlock(&bdevp->bd_mutex); > + mutex_unlock(&bdev->bd_mutex); > + bdput(bdevp); > + disk_put_part(part); > + return 0; > default: > return -EINVAL; > } Thanks, Maxim ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 2/2] util-linux: resizepart: Utility to resize a partition 2012-02-14 20:39 [PATCH 0/2][V3] block: Support online resize of disk partitions Vivek Goyal 2012-02-14 20:39 ` [PATCH 1/2] block: add partition resize function to blkpg ioctl Vivek Goyal @ 2012-02-14 20:39 ` Vivek Goyal 1 sibling, 0 replies; 12+ messages in thread From: Vivek Goyal @ 2012-02-14 20:39 UTC (permalink / raw) To: linux-kernel, axboe, dm-devel, kzak; +Cc: vgoyal, psusi, psusi, maxim.patlasov A simple user space utility to resize an existing partition. It tries to read the start of partiton from sysfs. This is a real quick dirty patch I used for my testing. I am sure there are better and faster ways of getting to partition "start" from device and partition number. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- partx/Makefile.am | 9 ++++- partx/partx.h | 19 ++++++++++ partx/resizepart.8 | 38 +++++++++++++++++++++ partx/resizepart.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 159 insertions(+), 2 deletions(-) create mode 100644 partx/resizepart.8 create mode 100644 partx/resizepart.c diff --git a/partx/Makefile.am b/partx/Makefile.am index 080bc47..72b605c 100644 --- a/partx/Makefile.am +++ b/partx/Makefile.am @@ -1,7 +1,12 @@ include $(top_srcdir)/config/include-Makefile.am -usrsbin_exec_PROGRAMS = addpart delpart -dist_man_MANS = addpart.8 delpart.8 +usrsbin_exec_PROGRAMS = addpart delpart resizepart +dist_man_MANS = addpart.8 delpart.8 resizepart.8 + +resizepart_SOURCES = resizepart.c \ + $(top_srcdir)/lib/sysfs.c \ + $(top_srcdir)/lib/canonicalize.c \ + $(top_srcdir)/lib/at.c usrsbin_exec_PROGRAMS += partx partx_SOURCES = partx.c partx.h \ diff --git a/partx/partx.h b/partx/partx.h index b40fa8f..c2b87f0 100644 --- a/partx/partx.h +++ b/partx/partx.h @@ -41,4 +41,23 @@ static inline int partx_add_partition(int fd, int partno, return ioctl(fd, BLKPG, &a); } +static inline int partx_resize_partition(int fd, int partno, + long long start, long long size) +{ + struct blkpg_ioctl_arg a; + struct blkpg_partition p; + + p.pno = partno; + p.start = start << 9; + p.length = size << 9; + p.devname[0] = 0; + p.volname[0] = 0; + a.op = BLKPG_RESIZE_PARTITION; + a.flags = 0; + a.datalen = sizeof(p); + a.data = &p; + + return ioctl(fd, BLKPG, &a); +} + #endif /* UTIL_LINUX_PARTX_H */ diff --git a/partx/resizepart.8 b/partx/resizepart.8 new file mode 100644 index 0000000..0b47e81 --- /dev/null +++ b/partx/resizepart.8 @@ -0,0 +1,38 @@ +.\" resizepart.8 -- +.\" Copyright 2012 Vivek Goyal <vgoyal@redhat.com> +.\" Copyright 2012 Red Hat, Inc. +.\" May be distributed under the GNU General Public License +.TH RESIZEPART 8 "February 2012" "util-linux" "System Administration" +.SH NAME +resizepart \- +simple wrapper around the "resize partition" ioctl +.SH SYNOPSIS +.B resizepart +.I device partition length +.SH DESCRIPTION +.B resizepart +is a program that informs the Linux kernel of new partition size. + +This command doesn't manipulate partitions on hard drive. + +.SH PARAMETERS +.TP +.I device +Specify the disk device. +.TP +.I partition +Specify the partition number. +.TP +.I length +Specify the length of the partition (in 512-byte sectors). + +.SH SEE ALSO +.BR addpart (8), +.BR delpart (8), +.BR fdisk (8), +.BR parted (8), +.BR partprobe (8), +.BR partx (8) +.SH AVAILABILITY +The addpart command is part of the util-linux package and is available from +ftp://ftp.kernel.org/pub/linux/utils/util-linux/. diff --git a/partx/resizepart.c b/partx/resizepart.c new file mode 100644 index 0000000..64dcfdb --- /dev/null +++ b/partx/resizepart.c @@ -0,0 +1,95 @@ +#include <stdio.h> +#include <stdlib.h> +#include <fcntl.h> +#include <ctype.h> +#include "canonicalize.h" +#include "sysfs.h" +#include "partx.h" + +char * +get_devname_from_canonical_path(char *path) +{ + struct sysfs_cxt cxt; + dev_t devno; + char name[PATH_MAX]; + char *devname; + + devno = sysfs_devname_to_devno(path, NULL); + if (!devno) { + fprintf(stderr, "failed to read devno. \n"); + exit(1); + } + + sysfs_init(&cxt, devno, NULL); + devname = sysfs_get_devname(&cxt, name, sizeof(name)); + return strdup(devname); +} + +char * +get_partname_from_devname(char *devname, int partno) +{ + char partname[PATH_MAX]; + + if (isdigit(devname[strlen(devname) - 1])) + snprintf(partname, PATH_MAX, "%sp%d", devname, partno); + else + snprintf(partname, PATH_MAX, "%s%d", devname, partno); + + return strdup(partname); +} + + +int +main(int argc, char **argv) +{ + int fd; + char *real_path, *devname, *partname, *pstart; + char part_sysfs_path[PATH_MAX], part_start[30]; + FILE *fp; + + if (argc != 4) { + fprintf(stderr, + "usage: %s diskdevice partitionnr length\n", + argv[0]); + exit(1); + } + if ((fd = open(argv[1], O_RDONLY)) < 0) { + perror(argv[1]); + exit(1); + } + + real_path = canonicalize_path(argv[1]); + + if (real_path == NULL) { + fprintf(stderr, "canonicalize_path(%s) failed. \n", argv[1]); + exit(1); + } + + devname = get_devname_from_canonical_path(real_path); + partname = get_partname_from_devname(devname, atoi(argv[2])); + + snprintf(part_sysfs_path, PATH_MAX, "/sys/block/%s/%s/start", + devname, partname); + + fp = fopen(part_sysfs_path, "r"); + + if (!fp) { + perror("BLKPG"); + exit(1); + } + + pstart = fgets(part_start, 30, fp); + + if (!pstart) { + perror("BLKPG"); + exit(1); + } + + if (partx_resize_partition(fd, atoi(argv[2]), atoll(pstart), + atoll(argv[3]))) { + perror("BLKPG"); + exit(1); + } + + return 0; +} -- 1.7.6.4 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [patch 0/2] [V4] block: Support online resize of disk partitions
@ 2012-07-09 21:34 vgoyal
2012-07-09 21:34 ` [patch 1/2] block: add partition resize function to blkpg ioctl vgoyal
0 siblings, 1 reply; 12+ messages in thread
From: vgoyal @ 2012-07-09 21:34 UTC (permalink / raw)
To: linux-kernel, axboe, dm-devel, kzak; +Cc: psusi, vgoyal, maxim.patlasov
Hi,
Few people have pinged me in rencent past about status of this patch, hence,
this is V4 of patch which adds support for online resizing of a partition.
This patch is based on previously posted patches by Phillip Susi.
There are two patches. Out of which one is kernel patch and other one is
util-linux patch to add support of a user space utility "resizepart" to
allow resizing the partition.
This ioctl only resizes the partition size in kenrel and does not change
the size on disk. A user needs to make sure that corresponding changes
are made to disk data structures also using fdisk(or partx), if changes
are to be retained across reboot.
Changes since V3
----------------
- Do bdput() in error path as per the Maxim's review comments.
Changes since V2
----------------
- Do not ignore the "start" parameter in RESIZE ioctl.
- Change resizepart utility to parse sysfs to get to partition start.
Changes since V1
----------------
Following are changes since the version Phillip posted.
- RESIZE ioctl ignores the partition "start" and does not expect user to
specify one. Caller needs to just specify "device", "partition number" and
"size" of new partition.
- Got rid of part_nr_sects_write_begin/part_nr_sects_write_end functions
and replaced these with single part_nr_sects_write().
- Some sequence counter related changes are simply lifted from i_size_write().
- Initialized part->nr_sects_seq using seqcount_init().
Phillip, do let me know if I should put your signed-off-by also in the
patch.
Any review feedback is welcome.
I did following test.
- Create a partition of 10MB on a disk using fdisk.
- Add this partition to a volume group
- Use fdisk to increase the partition size to 20MB. (First delete the
partition and then create a new one of 20MB size).
- Use resizepart to extend partition size in kernel.
resizepart /dev/sdc 1 40960
- Do pvresize on partition so that physical volume can be incrased in
size online.
pvresize /dev/sda1
pvresize does recognize the new size. Also lsblk and /proc/partitions
report the new size of partition.
Thanks
Vivek
^ permalink raw reply [flat|nested] 12+ messages in thread* [patch 1/2] block: add partition resize function to blkpg ioctl 2012-07-09 21:34 [patch 0/2] [V4] block: Support online resize of disk partitions vgoyal @ 2012-07-09 21:34 ` vgoyal 0 siblings, 0 replies; 12+ messages in thread From: vgoyal @ 2012-07-09 21:34 UTC (permalink / raw) To: linux-kernel, axboe, dm-devel, kzak; +Cc: psusi, vgoyal, maxim.patlasov [-- Attachment #1: 0001-block-add-partition-resize-function-to-blkpg-ioctl.patch --] [-- Type: text/plain, Size: 9882 bytes --] Add a new operation code (BLKPG_RESIZE_PARTITION) to the BLKPG ioctl that allows altering the size of an existing partition, even if it is currently in use. This patch converts hd_struct->nr_sects into sequence counter because One might extend a partition while IO is happening to it and update of nr_sects can be non-atomic on 32bit machines with 64bit sector_t. This can lead to issues like reading inconsistent size of a partition. Sequence counter have been used so that readers don't have to take bdev mutex lock as we call sector_in_part() very frequently. Now all the access to hd_struct->nr_sects should happen using sequence counter read/update helper functions part_nr_sects_read/part_nr_sects_write. There is one exception though, set_capacity()/get_capacity(). I think theoritically race should exist there too but this patch does not modify set_capacity()/get_capacity() due to sheer number of call sites and I am afraid that change might break something. I have left that as a TODO item. We can handle it later if need be. This patch does not introduce any new races as such w.r.t set_capacity()/get_capacity(). Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- block/genhd.c | 20 +++++++++++---- block/ioctl.c | 59 ++++++++++++++++++++++++++++++++++++++++++-- block/partition-generic.c | 4 ++- include/linux/blkpg.h | 1 + include/linux/genhd.h | 57 +++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 132 insertions(+), 9 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 9cf5583..cac7366 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -154,7 +154,7 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) part = rcu_dereference(ptbl->part[piter->idx]); if (!part) continue; - if (!part->nr_sects && + if (!part_nr_sects_read(part) && !(piter->flags & DISK_PITER_INCL_EMPTY) && !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && piter->idx == 0)) @@ -191,7 +191,7 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit); static inline int sector_in_part(struct hd_struct *part, sector_t sector) { return part->start_sect <= sector && - sector < part->start_sect + part->nr_sects; + sector < part->start_sect + part_nr_sects_read(part); } /** @@ -769,8 +769,8 @@ void __init printk_all_partitions(void) printk("%s%s %10llu %s %s", is_part0 ? "" : " ", bdevt_str(part_devt(part), devt_buf), - (unsigned long long)part->nr_sects >> 1, - disk_name(disk, part->partno, name_buf), + (unsigned long long)part_nr_sects_read(part) >> 1 + , disk_name(disk, part->partno, name_buf), uuid_buf); if (is_part0) { if (disk->driverfs_dev != NULL && @@ -862,7 +862,7 @@ static int show_partition(struct seq_file *seqf, void *v) while ((part = disk_part_iter_next(&piter))) seq_printf(seqf, "%4d %7d %10llu %s\n", MAJOR(part_devt(part)), MINOR(part_devt(part)), - (unsigned long long)part->nr_sects >> 1, + (unsigned long long)part_nr_sects_read(part) >> 1, disk_name(sgp, part->partno, buf)); disk_part_iter_exit(&piter); @@ -1268,6 +1268,16 @@ struct gendisk *alloc_disk_node(int minors, int node_id) } disk->part_tbl->part[0] = &disk->part0; + /* + * set_capacity() and get_capacity() currently don't use + * seqcounter to read/update the part0->nr_sects. Still init + * the counter as we can read the sectors in IO submission + * patch using seqence counters. + * + * TODO: Ideally set_capacity() and get_capacity() should be + * converted to make use of bd_mutex and sequence counters. + */ + seqcount_init(&disk->part0.nr_sects_seq); hd_ref_init(&disk->part0); disk->minors = minors; diff --git a/block/ioctl.c b/block/ioctl.c index ba15b2d..4476e0e8 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -13,7 +13,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user { struct block_device *bdevp; struct gendisk *disk; - struct hd_struct *part; + struct hd_struct *part, *lpart; struct blkpg_ioctl_arg a; struct blkpg_partition p; struct disk_part_iter piter; @@ -36,8 +36,8 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user case BLKPG_ADD_PARTITION: start = p.start >> 9; length = p.length >> 9; - /* check for fit in a hd_struct */ - if (sizeof(sector_t) == sizeof(long) && + /* check for fit in a hd_struct */ + if (sizeof(sector_t) == sizeof(long) && sizeof(long long) > sizeof(long)) { long pstart = start, plength = length; if (pstart != start || plength != length @@ -92,6 +92,59 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user bdput(bdevp); return 0; + case BLKPG_RESIZE_PARTITION: + start = p.start >> 9; + /* new length of partition in bytes */ + length = p.length >> 9; + /* check for fit in a hd_struct */ + if (sizeof(sector_t) == sizeof(long) && + sizeof(long long) > sizeof(long)) { + long pstart = start, plength = length; + if (pstart != start || plength != length + || pstart < 0 || plength < 0) + return -EINVAL; + } + part = disk_get_part(disk, partno); + if (!part) + return -ENXIO; + bdevp = bdget(part_devt(part)); + if (!bdevp) { + disk_put_part(part); + return -ENOMEM; + } + mutex_lock(&bdevp->bd_mutex); + mutex_lock_nested(&bdev->bd_mutex, 1); + if (start != part->start_sect) { + mutex_unlock(&bdevp->bd_mutex); + mutex_unlock(&bdev->bd_mutex); + bdput(bdevp); + disk_put_part(part); + return -EINVAL; + } + /* overlap? */ + disk_part_iter_init(&piter, disk, + DISK_PITER_INCL_EMPTY); + while ((lpart = disk_part_iter_next(&piter))) { + if (lpart->partno != partno && + !(start + length <= lpart->start_sect || + start >= lpart->start_sect + lpart->nr_sects) + ) { + disk_part_iter_exit(&piter); + mutex_unlock(&bdevp->bd_mutex); + mutex_unlock(&bdev->bd_mutex); + bdput(bdevp); + disk_put_part(part); + return -EBUSY; + } + } + disk_part_iter_exit(&piter); + part_nr_sects_write(part, (sector_t)length); + i_size_write(bdevp->bd_inode, p.length); + mutex_unlock(&bdevp->bd_mutex); + mutex_unlock(&bdev->bd_mutex); + bdput(bdevp); + disk_put_part(part); + return 0; default: return -EINVAL; } diff --git a/block/partition-generic.c b/block/partition-generic.c index 6df5d69..f1d1451 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -84,7 +84,7 @@ ssize_t part_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); - return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects); + return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p)); } static ssize_t part_ro_show(struct device *dev, @@ -294,6 +294,8 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, err = -ENOMEM; goto out_free; } + + seqcount_init(&p->nr_sects_seq); pdev = part_to_dev(p); p->start_sect = start; diff --git a/include/linux/blkpg.h b/include/linux/blkpg.h index faf8a45..a851944 100644 --- a/include/linux/blkpg.h +++ b/include/linux/blkpg.h @@ -40,6 +40,7 @@ struct blkpg_ioctl_arg { /* The subfunctions (for the op field) */ #define BLKPG_ADD_PARTITION 1 #define BLKPG_DEL_PARTITION 2 +#define BLKPG_RESIZE_PARTITION 3 /* Sizes of name fields. Unused at present. */ #define BLKPG_DEVNAMELTH 64 diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 017a7fb..ee8e688 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -98,7 +98,13 @@ struct partition_meta_info { struct hd_struct { sector_t start_sect; + /* + * nr_sects is protected by sequence counter. One might extend a + * partition while IO is happening to it and update of nr_sects + * can be non-atomic on 32bit machines with 64bit sector_t. + */ sector_t nr_sects; + seqcount_t nr_sects_seq; sector_t alignment_offset; unsigned int discard_alignment; struct device __dev; @@ -648,6 +654,57 @@ static inline void hd_struct_put(struct hd_struct *part) __delete_partition(part); } +/* + * Any access of part->nr_sects which is not protected by partition + * bd_mutex or gendisk bdev bd_mutex, should be done using this + * accessor function. + * + * Code written along the lines of i_size_read() and i_size_write(). + * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption + * on. + */ +static inline sector_t part_nr_sects_read(struct hd_struct *part) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) + sector_t nr_sects; + unsigned seq; + do { + seq = read_seqcount_begin(&part->nr_sects_seq); + nr_sects = part->nr_sects; + } while (read_seqcount_retry(&part->nr_sects_seq, seq)); + return nr_sects; +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) + sector_t nr_sects; + + preempt_disable(); + nr_sects = part->nr_sects; + preempt_enable(); + return nr_sects; +#else + return part->nr_sects; +#endif +} + +/* + * Should be called with mutex lock held (typically bd_mutex) of partition + * to provide mutual exlusion among writers otherwise seqcount might be + * left in wrong state leaving the readers spinning infinitely. + */ +static inline void part_nr_sects_write(struct hd_struct *part, sector_t size) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) + write_seqcount_begin(&part->nr_sects_seq); + part->nr_sects = size; + write_seqcount_end(&part->nr_sects_seq); +#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT) + preempt_disable(); + part->nr_sects = size; + preempt_enable(); +#else + part->nr_sects = size; +#endif +} + #else /* CONFIG_BLOCK */ static inline void printk_all_partitions(void) { } -- 1.7.7.6 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 0/2] block: online resize of disk partitions @ 2012-02-13 19:30 Vivek Goyal 2012-02-13 19:30 ` [PATCH 1/2] block: add partition resize function to blkpg ioctl Vivek Goyal 0 siblings, 1 reply; 12+ messages in thread From: Vivek Goyal @ 2012-02-13 19:30 UTC (permalink / raw) To: linux-kernel, axboe, dm-devel, kzak; +Cc: vgoyal, psusi, psusi, maxim.patlasov Hi, Following patch adds support for online resizing of a partition. This patch is based on previously posted patches by Phillip Susi. There are two patches. Out of which one is kernel patch and other one is util-linux patch to add support of a user space utility "resizepart" to allow resizing the partition. This ioctl only resizes the partition size in kenrel and does not change the size on disk. A user needs to make sure that corresponding changes are made to disk data structures also using fdisk(or partx), if changes are to be retained across reboot. I made some changes according to the feedback received last time. Following are changes since the version Phillip posted. - RESIZE ioctl ignores the partition "start" and does not expect user to specify one. Caller needs to just specify "device", "partition number" and "size" of new partition. - Got rid of part_nr_sects_write_begin/part_nr_sects_write_end functions and replaced these with single part_nr_sects_write(). - Some sequence counter related changes are simply lifted from i_size_write(). - Initialized part->nr_sects_seq using seqcount_init(). Phillip, do let me know if I should put your signed-off-by also in the patch. Any feedback is welcome. I did following test. - Create a partition of 10MB on a disk using fdisk. - Add this partition to a volume group - Use fdisk to increase the partition size to 20MB. (First delete the partition and then create a new one of 20MB size). - Use resizepart to extend partition size in kernel. resizepart /dev/sdc 1 40960 - Do pvresize on partition so that physical volume can be incrased in size online. pvresize /dev/sda1 pvresize does recognize the new size. Also lsblk and /proc/partitions report the new size of partition. Thanks Vivek [PATCH 1/2] block: add partition resize function to blkpg ioctl [PATCH 2/2] resizepart: Utility to resize a partition ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 1/2] block: add partition resize function to blkpg ioctl 2012-02-13 19:30 [PATCH 0/2] block: online resize of disk partitions Vivek Goyal @ 2012-02-13 19:30 ` Vivek Goyal 0 siblings, 0 replies; 12+ messages in thread From: Vivek Goyal @ 2012-02-13 19:30 UTC (permalink / raw) To: linux-kernel, axboe, dm-devel, kzak; +Cc: vgoyal, psusi, psusi, maxim.patlasov Add a new operation code ( BLKPG_RESIZE_PARTITION ) to the BLKPG ioctl that allows altering the size of an existing partition, even if it is currently in use. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- block/genhd.c | 20 ++++++++++++---- block/ioctl.c | 51 +++++++++++++++++++++++++++++++++++++-- block/partition-generic.c | 4 ++- include/linux/blkpg.h | 1 + include/linux/genhd.h | 57 +++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 124 insertions(+), 9 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 23b4f70..935e09b 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -153,7 +153,7 @@ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) part = rcu_dereference(ptbl->part[piter->idx]); if (!part) continue; - if (!part->nr_sects && + if (!part_nr_sects_read(part) && !(piter->flags & DISK_PITER_INCL_EMPTY) && !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && piter->idx == 0)) @@ -190,7 +190,7 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit); static inline int sector_in_part(struct hd_struct *part, sector_t sector) { return part->start_sect <= sector && - sector < part->start_sect + part->nr_sects; + sector < part->start_sect + part_nr_sects_read(part); } /** @@ -765,8 +765,8 @@ void __init printk_all_partitions(void) printk("%s%s %10llu %s %s", is_part0 ? "" : " ", bdevt_str(part_devt(part), devt_buf), - (unsigned long long)part->nr_sects >> 1, - disk_name(disk, part->partno, name_buf), uuid); + (unsigned long long)part_nr_sects_read(part) >> 1 + , disk_name(disk, part->partno, name_buf), uuid); if (is_part0) { if (disk->driverfs_dev != NULL && disk->driverfs_dev->driver != NULL) @@ -857,7 +857,7 @@ static int show_partition(struct seq_file *seqf, void *v) while ((part = disk_part_iter_next(&piter))) seq_printf(seqf, "%4d %7d %10llu %s\n", MAJOR(part_devt(part)), MINOR(part_devt(part)), - (unsigned long long)part->nr_sects >> 1, + (unsigned long long)part_nr_sects_read(part) >> 1, disk_name(sgp, part->partno, buf)); disk_part_iter_exit(&piter); @@ -1263,6 +1263,16 @@ struct gendisk *alloc_disk_node(int minors, int node_id) } disk->part_tbl->part[0] = &disk->part0; + /* + * set_capacity() and get_capacity() currently don't use + * seqcounter to read/update the part0->nr_sects. Still init + * the counter as we can read the sectors in IO submission + * patch using seqence counters. + * + * TODO: Ideally set_capacity() and get_capacity() should be + * converted to make use of bd_mutex and sequence counters. + */ + seqcount_init(&disk->part0.nr_sects_seq); hd_ref_init(&disk->part0); disk->minors = minors; diff --git a/block/ioctl.c b/block/ioctl.c index ba15b2d..57d99b2 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -13,7 +13,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user { struct block_device *bdevp; struct gendisk *disk; - struct hd_struct *part; + struct hd_struct *part, *lpart; struct blkpg_ioctl_arg a; struct blkpg_partition p; struct disk_part_iter piter; @@ -36,8 +36,8 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user case BLKPG_ADD_PARTITION: start = p.start >> 9; length = p.length >> 9; - /* check for fit in a hd_struct */ - if (sizeof(sector_t) == sizeof(long) && + /* check for fit in a hd_struct */ + if (sizeof(sector_t) == sizeof(long) && sizeof(long long) > sizeof(long)) { long pstart = start, plength = length; if (pstart != start || plength != length @@ -92,6 +92,51 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user bdput(bdevp); return 0; + case BLKPG_RESIZE_PARTITION: + /* new length of partition in bytes */ + length = p.length >> 9; + /* check for fit in a hd_struct */ + if (sizeof(sector_t) == sizeof(long) && + sizeof(long long) > sizeof(long)) { + long plength = length; + if (plength != length || plength < 0) + return -EINVAL; + } + part = disk_get_part(disk, partno); + if (!part) + return -ENXIO; + bdevp = bdget(part_devt(part)); + if (!bdevp) { + disk_put_part(part); + return -ENOMEM; + } + mutex_lock(&bdevp->bd_mutex); + mutex_lock_nested(&bdev->bd_mutex, 1); + start = part->start_sect; + + /* overlap? */ + disk_part_iter_init(&piter, disk, + DISK_PITER_INCL_EMPTY); + while ((lpart = disk_part_iter_next(&piter))) { + if (lpart->partno != partno && + !(start + length <= lpart->start_sect || + start >= lpart->start_sect + lpart->nr_sects) + ) { + disk_part_iter_exit(&piter); + mutex_unlock(&bdevp->bd_mutex); + mutex_unlock(&bdev->bd_mutex); + disk_put_part(part); + return -EBUSY; + } + } + disk_part_iter_exit(&piter); + part_nr_sects_write(part, (sector_t)length); + i_size_write(bdevp->bd_inode, p.length); + mutex_unlock(&bdevp->bd_mutex); + mutex_unlock(&bdev->bd_mutex); + bdput(bdevp); + disk_put_part(part); + return 0; default: return -EINVAL; } diff --git a/block/partition-generic.c b/block/partition-generic.c index d06ec1c..363a6f6 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -84,7 +84,7 @@ ssize_t part_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); - return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects); + return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p)); } static ssize_t part_ro_show(struct device *dev, @@ -294,6 +294,8 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, err = -ENOMEM; goto out_free; } + + seqcount_init(&p->nr_sects_seq); pdev = part_to_dev(p); p->start_sect = start; diff --git a/include/linux/blkpg.h b/include/linux/blkpg.h index faf8a45..a851944 100644 --- a/include/linux/blkpg.h +++ b/include/linux/blkpg.h @@ -40,6 +40,7 @@ struct blkpg_ioctl_arg { /* The subfunctions (for the op field) */ #define BLKPG_ADD_PARTITION 1 #define BLKPG_DEL_PARTITION 2 +#define BLKPG_RESIZE_PARTITION 3 /* Sizes of name fields. Unused at present. */ #define BLKPG_DEVNAMELTH 64 diff --git a/include/linux/genhd.h b/include/linux/genhd.h index fe23ee7..0def3ef 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -98,7 +98,13 @@ struct partition_meta_info { struct hd_struct { sector_t start_sect; + /* + * nr_sects is protected by sequence counter. One might extend a + * partition while IO is happening to it and update of nr_sects + * can be non-atomic on 32bit machines with 64bit sector_t. + */ sector_t nr_sects; + seqcount_t nr_sects_seq; sector_t alignment_offset; unsigned int discard_alignment; struct device __dev; @@ -653,6 +659,57 @@ static inline void hd_struct_put(struct hd_struct *part) __delete_partition(part); } +/* + * Any access of part->nr_sects which is not protected by partition + * bd_mutex or gendisk bdev bd_mutex, should be done using this + * accessor function. + * + * Code written along the lines of i_size_read() and i_size_write(). + * CONFIG_PREEMPT case optimizes the case of UP kernel with preemption + * on. + */ +static inline sector_t part_nr_sects_read(struct hd_struct *part) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) + sector_t nr_sects; + unsigned seq; + do { + seq = read_seqcount_begin(&part->nr_sects_seq); + nr_sects = part->nr_sects; + } while (read_seqcount_retry(&part->nr_sects_seq, seq)); + return nr_sects; +#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) + sector_t nr_sects; + + preempt_disable(); + nr_sects = part->nr_sects; + preempt_enable(); + return nr_sects; +#else + return part->nr_sects; +#endif +} + +/* + * Should be called with mutex lock held (typically bd_mutex) of partition + * to provide mutual exlusion among writers otherwise seqcount might be + * left in wrong state leaving the readers spinning infinitely. + */ +static inline void part_nr_sects_write(struct hd_struct *part, sector_t size) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_SMP) + write_seqcount_begin(&part->nr_sects_seq); + part->nr_sects = size; + write_seqcount_end(&part->nr_sects_seq); +#elif BITS_PER_LONG==32 && defined(CONFIG_LBDAF) && defined(CONFIG_PREEMPT) + preempt_disable(); + part->nr_sects = size; + preempt_enable(); +#else + part->nr_sects = size; +#endif +} + #else /* CONFIG_BLOCK */ static inline void printk_all_partitions(void) { } -- 1.7.6.4 ^ permalink raw reply related [flat|nested] 12+ messages in thread
end of thread, other threads:[~2012-07-09 21:36 UTC | newest] Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2012-02-14 20:39 [PATCH 0/2][V3] block: Support online resize of disk partitions Vivek Goyal 2012-02-14 20:39 ` [PATCH 1/2] block: add partition resize function to blkpg ioctl Vivek Goyal 2012-02-20 14:42 ` Vivek Goyal 2012-02-20 15:17 ` Phillip Susi 2012-02-20 15:28 ` Vivek Goyal 2012-03-02 18:54 ` Vivek Goyal 2012-07-07 1:51 ` Phillip Susi 2012-07-09 15:13 ` Vivek Goyal 2012-04-09 16:40 ` Maxim V. Patlasov 2012-02-14 20:39 ` [PATCH 2/2] util-linux: resizepart: Utility to resize a partition Vivek Goyal -- strict thread matches above, loose matches on Subject: below -- 2012-07-09 21:34 [patch 0/2] [V4] block: Support online resize of disk partitions vgoyal 2012-07-09 21:34 ` [patch 1/2] block: add partition resize function to blkpg ioctl vgoyal 2012-02-13 19:30 [PATCH 0/2] block: online resize of disk partitions Vivek Goyal 2012-02-13 19:30 ` [PATCH 1/2] block: add partition resize function to blkpg ioctl Vivek Goyal
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