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7ac5360cd4
These methods indirect the actual DAX read/write path. In the end pmem uses magic flush and mc safe variants and fuse and dcssblk use plain ones while device mapper picks redirects to the underlying device. Add set_dax_nocache() and set_dax_nomc() APIs to control which copy routines are used to remove indirect call from the read/write fast path as well as a lot of boilerplate code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> [virtiofs] Link: https://lore.kernel.org/r/20211215084508.435401-5-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
973 lines
24 KiB
C
973 lines
24 KiB
C
/*
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* Copyright (C) 2014 Facebook. All rights reserved.
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*
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* This file is released under the GPL.
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*/
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#include <linux/device-mapper.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/blkdev.h>
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#include <linux/bio.h>
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#include <linux/dax.h>
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#include <linux/slab.h>
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#include <linux/kthread.h>
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#include <linux/freezer.h>
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#include <linux/uio.h>
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#define DM_MSG_PREFIX "log-writes"
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/*
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* This target will sequentially log all writes to the target device onto the
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* log device. This is helpful for replaying writes to check for fs consistency
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* at all times. This target provides a mechanism to mark specific events to
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* check data at a later time. So for example you would:
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*
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* write data
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* fsync
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* dmsetup message /dev/whatever mark mymark
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* unmount /mnt/test
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*
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* Then replay the log up to mymark and check the contents of the replay to
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* verify it matches what was written.
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*
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* We log writes only after they have been flushed, this makes the log describe
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* close to the order in which the data hits the actual disk, not its cache. So
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* for example the following sequence (W means write, C means complete)
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*
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* Wa,Wb,Wc,Cc,Ca,FLUSH,FUAd,Cb,CFLUSH,CFUAd
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*
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* Would result in the log looking like this:
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*
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* c,a,b,flush,fuad,<other writes>,<next flush>
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*
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* This is meant to help expose problems where file systems do not properly wait
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* on data being written before invoking a FLUSH. FUA bypasses cache so once it
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* completes it is added to the log as it should be on disk.
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*
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* We treat DISCARDs as if they don't bypass cache so that they are logged in
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* order of completion along with the normal writes. If we didn't do it this
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* way we would process all the discards first and then write all the data, when
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* in fact we want to do the data and the discard in the order that they
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* completed.
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*/
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#define LOG_FLUSH_FLAG (1 << 0)
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#define LOG_FUA_FLAG (1 << 1)
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#define LOG_DISCARD_FLAG (1 << 2)
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#define LOG_MARK_FLAG (1 << 3)
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#define LOG_METADATA_FLAG (1 << 4)
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#define WRITE_LOG_VERSION 1ULL
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#define WRITE_LOG_MAGIC 0x6a736677736872ULL
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#define WRITE_LOG_SUPER_SECTOR 0
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/*
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* The disk format for this is braindead simple.
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*
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* At byte 0 we have our super, followed by the following sequence for
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* nr_entries:
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*
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* [ 1 sector ][ entry->nr_sectors ]
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* [log_write_entry][ data written ]
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*
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* The log_write_entry takes up a full sector so we can have arbitrary length
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* marks and it leaves us room for extra content in the future.
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*/
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/*
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* Basic info about the log for userspace.
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*/
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struct log_write_super {
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__le64 magic;
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__le64 version;
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__le64 nr_entries;
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__le32 sectorsize;
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};
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/*
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* sector - the sector we wrote.
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* nr_sectors - the number of sectors we wrote.
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* flags - flags for this log entry.
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* data_len - the size of the data in this log entry, this is for private log
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* entry stuff, the MARK data provided by userspace for example.
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*/
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struct log_write_entry {
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__le64 sector;
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__le64 nr_sectors;
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__le64 flags;
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__le64 data_len;
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};
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struct log_writes_c {
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struct dm_dev *dev;
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struct dm_dev *logdev;
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u64 logged_entries;
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u32 sectorsize;
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u32 sectorshift;
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atomic_t io_blocks;
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atomic_t pending_blocks;
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sector_t next_sector;
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sector_t end_sector;
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bool logging_enabled;
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bool device_supports_discard;
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spinlock_t blocks_lock;
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struct list_head unflushed_blocks;
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struct list_head logging_blocks;
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wait_queue_head_t wait;
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struct task_struct *log_kthread;
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struct completion super_done;
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};
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struct pending_block {
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int vec_cnt;
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u64 flags;
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sector_t sector;
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sector_t nr_sectors;
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char *data;
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u32 datalen;
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struct list_head list;
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struct bio_vec vecs[];
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};
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struct per_bio_data {
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struct pending_block *block;
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};
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static inline sector_t bio_to_dev_sectors(struct log_writes_c *lc,
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sector_t sectors)
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{
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return sectors >> (lc->sectorshift - SECTOR_SHIFT);
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}
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static inline sector_t dev_to_bio_sectors(struct log_writes_c *lc,
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sector_t sectors)
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{
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return sectors << (lc->sectorshift - SECTOR_SHIFT);
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}
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static void put_pending_block(struct log_writes_c *lc)
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{
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if (atomic_dec_and_test(&lc->pending_blocks)) {
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smp_mb__after_atomic();
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if (waitqueue_active(&lc->wait))
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wake_up(&lc->wait);
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}
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}
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static void put_io_block(struct log_writes_c *lc)
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{
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if (atomic_dec_and_test(&lc->io_blocks)) {
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smp_mb__after_atomic();
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if (waitqueue_active(&lc->wait))
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wake_up(&lc->wait);
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}
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}
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static void log_end_io(struct bio *bio)
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{
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struct log_writes_c *lc = bio->bi_private;
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if (bio->bi_status) {
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unsigned long flags;
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DMERR("Error writing log block, error=%d", bio->bi_status);
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spin_lock_irqsave(&lc->blocks_lock, flags);
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lc->logging_enabled = false;
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spin_unlock_irqrestore(&lc->blocks_lock, flags);
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}
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bio_free_pages(bio);
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put_io_block(lc);
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bio_put(bio);
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}
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static void log_end_super(struct bio *bio)
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{
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struct log_writes_c *lc = bio->bi_private;
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complete(&lc->super_done);
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log_end_io(bio);
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}
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/*
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* Meant to be called if there is an error, it will free all the pages
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* associated with the block.
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*/
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static void free_pending_block(struct log_writes_c *lc,
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struct pending_block *block)
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{
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int i;
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for (i = 0; i < block->vec_cnt; i++) {
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if (block->vecs[i].bv_page)
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__free_page(block->vecs[i].bv_page);
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}
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kfree(block->data);
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kfree(block);
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put_pending_block(lc);
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}
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static int write_metadata(struct log_writes_c *lc, void *entry,
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size_t entrylen, void *data, size_t datalen,
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sector_t sector)
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{
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struct bio *bio;
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struct page *page;
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void *ptr;
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size_t ret;
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bio = bio_alloc(GFP_KERNEL, 1);
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if (!bio) {
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DMERR("Couldn't alloc log bio");
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goto error;
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}
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bio->bi_iter.bi_size = 0;
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bio->bi_iter.bi_sector = sector;
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bio_set_dev(bio, lc->logdev->bdev);
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bio->bi_end_io = (sector == WRITE_LOG_SUPER_SECTOR) ?
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log_end_super : log_end_io;
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bio->bi_private = lc;
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bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
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page = alloc_page(GFP_KERNEL);
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if (!page) {
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DMERR("Couldn't alloc log page");
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bio_put(bio);
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goto error;
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}
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ptr = kmap_atomic(page);
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memcpy(ptr, entry, entrylen);
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if (datalen)
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memcpy(ptr + entrylen, data, datalen);
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memset(ptr + entrylen + datalen, 0,
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lc->sectorsize - entrylen - datalen);
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kunmap_atomic(ptr);
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ret = bio_add_page(bio, page, lc->sectorsize, 0);
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if (ret != lc->sectorsize) {
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DMERR("Couldn't add page to the log block");
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goto error_bio;
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}
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submit_bio(bio);
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return 0;
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error_bio:
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bio_put(bio);
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__free_page(page);
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error:
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put_io_block(lc);
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return -1;
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}
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static int write_inline_data(struct log_writes_c *lc, void *entry,
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size_t entrylen, void *data, size_t datalen,
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sector_t sector)
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{
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int bio_pages, pg_datalen, pg_sectorlen, i;
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struct page *page;
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struct bio *bio;
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size_t ret;
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void *ptr;
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while (datalen) {
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bio_pages = bio_max_segs(DIV_ROUND_UP(datalen, PAGE_SIZE));
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atomic_inc(&lc->io_blocks);
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bio = bio_alloc(GFP_KERNEL, bio_pages);
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if (!bio) {
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DMERR("Couldn't alloc inline data bio");
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goto error;
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}
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bio->bi_iter.bi_size = 0;
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bio->bi_iter.bi_sector = sector;
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bio_set_dev(bio, lc->logdev->bdev);
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bio->bi_end_io = log_end_io;
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bio->bi_private = lc;
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bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
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for (i = 0; i < bio_pages; i++) {
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pg_datalen = min_t(int, datalen, PAGE_SIZE);
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pg_sectorlen = ALIGN(pg_datalen, lc->sectorsize);
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page = alloc_page(GFP_KERNEL);
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if (!page) {
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DMERR("Couldn't alloc inline data page");
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goto error_bio;
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}
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ptr = kmap_atomic(page);
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memcpy(ptr, data, pg_datalen);
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if (pg_sectorlen > pg_datalen)
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memset(ptr + pg_datalen, 0, pg_sectorlen - pg_datalen);
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kunmap_atomic(ptr);
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ret = bio_add_page(bio, page, pg_sectorlen, 0);
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if (ret != pg_sectorlen) {
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DMERR("Couldn't add page of inline data");
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__free_page(page);
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goto error_bio;
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}
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datalen -= pg_datalen;
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data += pg_datalen;
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}
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submit_bio(bio);
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sector += bio_pages * PAGE_SECTORS;
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}
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return 0;
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error_bio:
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bio_free_pages(bio);
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bio_put(bio);
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error:
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put_io_block(lc);
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return -1;
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}
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static int log_one_block(struct log_writes_c *lc,
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struct pending_block *block, sector_t sector)
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{
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struct bio *bio;
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struct log_write_entry entry;
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size_t metadatalen, ret;
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int i;
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entry.sector = cpu_to_le64(block->sector);
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entry.nr_sectors = cpu_to_le64(block->nr_sectors);
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entry.flags = cpu_to_le64(block->flags);
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entry.data_len = cpu_to_le64(block->datalen);
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metadatalen = (block->flags & LOG_MARK_FLAG) ? block->datalen : 0;
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if (write_metadata(lc, &entry, sizeof(entry), block->data,
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metadatalen, sector)) {
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free_pending_block(lc, block);
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return -1;
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}
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sector += dev_to_bio_sectors(lc, 1);
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if (block->datalen && metadatalen == 0) {
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if (write_inline_data(lc, &entry, sizeof(entry), block->data,
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block->datalen, sector)) {
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free_pending_block(lc, block);
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return -1;
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}
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/* we don't support both inline data & bio data */
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goto out;
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}
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if (!block->vec_cnt)
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goto out;
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atomic_inc(&lc->io_blocks);
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bio = bio_alloc(GFP_KERNEL, bio_max_segs(block->vec_cnt));
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if (!bio) {
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DMERR("Couldn't alloc log bio");
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goto error;
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}
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bio->bi_iter.bi_size = 0;
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bio->bi_iter.bi_sector = sector;
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bio_set_dev(bio, lc->logdev->bdev);
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bio->bi_end_io = log_end_io;
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bio->bi_private = lc;
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bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
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for (i = 0; i < block->vec_cnt; i++) {
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/*
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* The page offset is always 0 because we allocate a new page
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* for every bvec in the original bio for simplicity sake.
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*/
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ret = bio_add_page(bio, block->vecs[i].bv_page,
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block->vecs[i].bv_len, 0);
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if (ret != block->vecs[i].bv_len) {
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atomic_inc(&lc->io_blocks);
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submit_bio(bio);
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bio = bio_alloc(GFP_KERNEL,
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bio_max_segs(block->vec_cnt - i));
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if (!bio) {
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DMERR("Couldn't alloc log bio");
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goto error;
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}
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bio->bi_iter.bi_size = 0;
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bio->bi_iter.bi_sector = sector;
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bio_set_dev(bio, lc->logdev->bdev);
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bio->bi_end_io = log_end_io;
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bio->bi_private = lc;
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bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
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ret = bio_add_page(bio, block->vecs[i].bv_page,
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block->vecs[i].bv_len, 0);
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if (ret != block->vecs[i].bv_len) {
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DMERR("Couldn't add page on new bio?");
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bio_put(bio);
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goto error;
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}
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}
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sector += block->vecs[i].bv_len >> SECTOR_SHIFT;
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}
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submit_bio(bio);
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out:
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kfree(block->data);
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kfree(block);
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put_pending_block(lc);
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return 0;
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error:
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free_pending_block(lc, block);
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put_io_block(lc);
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return -1;
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}
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static int log_super(struct log_writes_c *lc)
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{
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struct log_write_super super;
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super.magic = cpu_to_le64(WRITE_LOG_MAGIC);
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super.version = cpu_to_le64(WRITE_LOG_VERSION);
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super.nr_entries = cpu_to_le64(lc->logged_entries);
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super.sectorsize = cpu_to_le32(lc->sectorsize);
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if (write_metadata(lc, &super, sizeof(super), NULL, 0,
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WRITE_LOG_SUPER_SECTOR)) {
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DMERR("Couldn't write super");
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return -1;
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}
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|
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/*
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* Super sector should be writen in-order, otherwise the
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* nr_entries could be rewritten incorrectly by an old bio.
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*/
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wait_for_completion_io(&lc->super_done);
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return 0;
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}
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static inline sector_t logdev_last_sector(struct log_writes_c *lc)
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{
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return bdev_nr_sectors(lc->logdev->bdev);
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}
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static int log_writes_kthread(void *arg)
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{
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struct log_writes_c *lc = (struct log_writes_c *)arg;
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sector_t sector = 0;
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|
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while (!kthread_should_stop()) {
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bool super = false;
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bool logging_enabled;
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struct pending_block *block = NULL;
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int ret;
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|
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spin_lock_irq(&lc->blocks_lock);
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if (!list_empty(&lc->logging_blocks)) {
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block = list_first_entry(&lc->logging_blocks,
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struct pending_block, list);
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list_del_init(&block->list);
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if (!lc->logging_enabled)
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goto next;
|
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sector = lc->next_sector;
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if (!(block->flags & LOG_DISCARD_FLAG))
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lc->next_sector += dev_to_bio_sectors(lc, block->nr_sectors);
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lc->next_sector += dev_to_bio_sectors(lc, 1);
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|
|
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/*
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* Apparently the size of the device may not be known
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* right away, so handle this properly.
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*/
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if (!lc->end_sector)
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lc->end_sector = logdev_last_sector(lc);
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if (lc->end_sector &&
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lc->next_sector >= lc->end_sector) {
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DMERR("Ran out of space on the logdev");
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lc->logging_enabled = false;
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goto next;
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}
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lc->logged_entries++;
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atomic_inc(&lc->io_blocks);
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|
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super = (block->flags & (LOG_FUA_FLAG | LOG_MARK_FLAG));
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if (super)
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atomic_inc(&lc->io_blocks);
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}
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next:
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logging_enabled = lc->logging_enabled;
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spin_unlock_irq(&lc->blocks_lock);
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if (block) {
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if (logging_enabled) {
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ret = log_one_block(lc, block, sector);
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if (!ret && super)
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ret = log_super(lc);
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if (ret) {
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spin_lock_irq(&lc->blocks_lock);
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lc->logging_enabled = false;
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spin_unlock_irq(&lc->blocks_lock);
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}
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} else
|
|
free_pending_block(lc, block);
|
|
continue;
|
|
}
|
|
|
|
if (!try_to_freeze()) {
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
if (!kthread_should_stop() &&
|
|
list_empty(&lc->logging_blocks))
|
|
schedule();
|
|
__set_current_state(TASK_RUNNING);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Construct a log-writes mapping:
|
|
* log-writes <dev_path> <log_dev_path>
|
|
*/
|
|
static int log_writes_ctr(struct dm_target *ti, unsigned int argc, char **argv)
|
|
{
|
|
struct log_writes_c *lc;
|
|
struct dm_arg_set as;
|
|
const char *devname, *logdevname;
|
|
int ret;
|
|
|
|
as.argc = argc;
|
|
as.argv = argv;
|
|
|
|
if (argc < 2) {
|
|
ti->error = "Invalid argument count";
|
|
return -EINVAL;
|
|
}
|
|
|
|
lc = kzalloc(sizeof(struct log_writes_c), GFP_KERNEL);
|
|
if (!lc) {
|
|
ti->error = "Cannot allocate context";
|
|
return -ENOMEM;
|
|
}
|
|
spin_lock_init(&lc->blocks_lock);
|
|
INIT_LIST_HEAD(&lc->unflushed_blocks);
|
|
INIT_LIST_HEAD(&lc->logging_blocks);
|
|
init_waitqueue_head(&lc->wait);
|
|
init_completion(&lc->super_done);
|
|
atomic_set(&lc->io_blocks, 0);
|
|
atomic_set(&lc->pending_blocks, 0);
|
|
|
|
devname = dm_shift_arg(&as);
|
|
ret = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &lc->dev);
|
|
if (ret) {
|
|
ti->error = "Device lookup failed";
|
|
goto bad;
|
|
}
|
|
|
|
logdevname = dm_shift_arg(&as);
|
|
ret = dm_get_device(ti, logdevname, dm_table_get_mode(ti->table),
|
|
&lc->logdev);
|
|
if (ret) {
|
|
ti->error = "Log device lookup failed";
|
|
dm_put_device(ti, lc->dev);
|
|
goto bad;
|
|
}
|
|
|
|
lc->sectorsize = bdev_logical_block_size(lc->dev->bdev);
|
|
lc->sectorshift = ilog2(lc->sectorsize);
|
|
lc->log_kthread = kthread_run(log_writes_kthread, lc, "log-write");
|
|
if (IS_ERR(lc->log_kthread)) {
|
|
ret = PTR_ERR(lc->log_kthread);
|
|
ti->error = "Couldn't alloc kthread";
|
|
dm_put_device(ti, lc->dev);
|
|
dm_put_device(ti, lc->logdev);
|
|
goto bad;
|
|
}
|
|
|
|
/*
|
|
* next_sector is in 512b sectors to correspond to what bi_sector expects.
|
|
* The super starts at sector 0, and the next_sector is the next logical
|
|
* one based on the sectorsize of the device.
|
|
*/
|
|
lc->next_sector = lc->sectorsize >> SECTOR_SHIFT;
|
|
lc->logging_enabled = true;
|
|
lc->end_sector = logdev_last_sector(lc);
|
|
lc->device_supports_discard = true;
|
|
|
|
ti->num_flush_bios = 1;
|
|
ti->flush_supported = true;
|
|
ti->num_discard_bios = 1;
|
|
ti->discards_supported = true;
|
|
ti->per_io_data_size = sizeof(struct per_bio_data);
|
|
ti->private = lc;
|
|
return 0;
|
|
|
|
bad:
|
|
kfree(lc);
|
|
return ret;
|
|
}
|
|
|
|
static int log_mark(struct log_writes_c *lc, char *data)
|
|
{
|
|
struct pending_block *block;
|
|
size_t maxsize = lc->sectorsize - sizeof(struct log_write_entry);
|
|
|
|
block = kzalloc(sizeof(struct pending_block), GFP_KERNEL);
|
|
if (!block) {
|
|
DMERR("Error allocating pending block");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
block->data = kstrndup(data, maxsize - 1, GFP_KERNEL);
|
|
if (!block->data) {
|
|
DMERR("Error copying mark data");
|
|
kfree(block);
|
|
return -ENOMEM;
|
|
}
|
|
atomic_inc(&lc->pending_blocks);
|
|
block->datalen = strlen(block->data);
|
|
block->flags |= LOG_MARK_FLAG;
|
|
spin_lock_irq(&lc->blocks_lock);
|
|
list_add_tail(&block->list, &lc->logging_blocks);
|
|
spin_unlock_irq(&lc->blocks_lock);
|
|
wake_up_process(lc->log_kthread);
|
|
return 0;
|
|
}
|
|
|
|
static void log_writes_dtr(struct dm_target *ti)
|
|
{
|
|
struct log_writes_c *lc = ti->private;
|
|
|
|
spin_lock_irq(&lc->blocks_lock);
|
|
list_splice_init(&lc->unflushed_blocks, &lc->logging_blocks);
|
|
spin_unlock_irq(&lc->blocks_lock);
|
|
|
|
/*
|
|
* This is just nice to have since it'll update the super to include the
|
|
* unflushed blocks, if it fails we don't really care.
|
|
*/
|
|
log_mark(lc, "dm-log-writes-end");
|
|
wake_up_process(lc->log_kthread);
|
|
wait_event(lc->wait, !atomic_read(&lc->io_blocks) &&
|
|
!atomic_read(&lc->pending_blocks));
|
|
kthread_stop(lc->log_kthread);
|
|
|
|
WARN_ON(!list_empty(&lc->logging_blocks));
|
|
WARN_ON(!list_empty(&lc->unflushed_blocks));
|
|
dm_put_device(ti, lc->dev);
|
|
dm_put_device(ti, lc->logdev);
|
|
kfree(lc);
|
|
}
|
|
|
|
static void normal_map_bio(struct dm_target *ti, struct bio *bio)
|
|
{
|
|
struct log_writes_c *lc = ti->private;
|
|
|
|
bio_set_dev(bio, lc->dev->bdev);
|
|
}
|
|
|
|
static int log_writes_map(struct dm_target *ti, struct bio *bio)
|
|
{
|
|
struct log_writes_c *lc = ti->private;
|
|
struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
|
|
struct pending_block *block;
|
|
struct bvec_iter iter;
|
|
struct bio_vec bv;
|
|
size_t alloc_size;
|
|
int i = 0;
|
|
bool flush_bio = (bio->bi_opf & REQ_PREFLUSH);
|
|
bool fua_bio = (bio->bi_opf & REQ_FUA);
|
|
bool discard_bio = (bio_op(bio) == REQ_OP_DISCARD);
|
|
bool meta_bio = (bio->bi_opf & REQ_META);
|
|
|
|
pb->block = NULL;
|
|
|
|
/* Don't bother doing anything if logging has been disabled */
|
|
if (!lc->logging_enabled)
|
|
goto map_bio;
|
|
|
|
/*
|
|
* Map reads as normal.
|
|
*/
|
|
if (bio_data_dir(bio) == READ)
|
|
goto map_bio;
|
|
|
|
/* No sectors and not a flush? Don't care */
|
|
if (!bio_sectors(bio) && !flush_bio)
|
|
goto map_bio;
|
|
|
|
/*
|
|
* Discards will have bi_size set but there's no actual data, so just
|
|
* allocate the size of the pending block.
|
|
*/
|
|
if (discard_bio)
|
|
alloc_size = sizeof(struct pending_block);
|
|
else
|
|
alloc_size = struct_size(block, vecs, bio_segments(bio));
|
|
|
|
block = kzalloc(alloc_size, GFP_NOIO);
|
|
if (!block) {
|
|
DMERR("Error allocating pending block");
|
|
spin_lock_irq(&lc->blocks_lock);
|
|
lc->logging_enabled = false;
|
|
spin_unlock_irq(&lc->blocks_lock);
|
|
return DM_MAPIO_KILL;
|
|
}
|
|
INIT_LIST_HEAD(&block->list);
|
|
pb->block = block;
|
|
atomic_inc(&lc->pending_blocks);
|
|
|
|
if (flush_bio)
|
|
block->flags |= LOG_FLUSH_FLAG;
|
|
if (fua_bio)
|
|
block->flags |= LOG_FUA_FLAG;
|
|
if (discard_bio)
|
|
block->flags |= LOG_DISCARD_FLAG;
|
|
if (meta_bio)
|
|
block->flags |= LOG_METADATA_FLAG;
|
|
|
|
block->sector = bio_to_dev_sectors(lc, bio->bi_iter.bi_sector);
|
|
block->nr_sectors = bio_to_dev_sectors(lc, bio_sectors(bio));
|
|
|
|
/* We don't need the data, just submit */
|
|
if (discard_bio) {
|
|
WARN_ON(flush_bio || fua_bio);
|
|
if (lc->device_supports_discard)
|
|
goto map_bio;
|
|
bio_endio(bio);
|
|
return DM_MAPIO_SUBMITTED;
|
|
}
|
|
|
|
/* Flush bio, splice the unflushed blocks onto this list and submit */
|
|
if (flush_bio && !bio_sectors(bio)) {
|
|
spin_lock_irq(&lc->blocks_lock);
|
|
list_splice_init(&lc->unflushed_blocks, &block->list);
|
|
spin_unlock_irq(&lc->blocks_lock);
|
|
goto map_bio;
|
|
}
|
|
|
|
/*
|
|
* We will write this bio somewhere else way later so we need to copy
|
|
* the actual contents into new pages so we know the data will always be
|
|
* there.
|
|
*
|
|
* We do this because this could be a bio from O_DIRECT in which case we
|
|
* can't just hold onto the page until some later point, we have to
|
|
* manually copy the contents.
|
|
*/
|
|
bio_for_each_segment(bv, bio, iter) {
|
|
struct page *page;
|
|
void *dst;
|
|
|
|
page = alloc_page(GFP_NOIO);
|
|
if (!page) {
|
|
DMERR("Error allocing page");
|
|
free_pending_block(lc, block);
|
|
spin_lock_irq(&lc->blocks_lock);
|
|
lc->logging_enabled = false;
|
|
spin_unlock_irq(&lc->blocks_lock);
|
|
return DM_MAPIO_KILL;
|
|
}
|
|
|
|
dst = kmap_atomic(page);
|
|
memcpy_from_bvec(dst, &bv);
|
|
kunmap_atomic(dst);
|
|
block->vecs[i].bv_page = page;
|
|
block->vecs[i].bv_len = bv.bv_len;
|
|
block->vec_cnt++;
|
|
i++;
|
|
}
|
|
|
|
/* Had a flush with data in it, weird */
|
|
if (flush_bio) {
|
|
spin_lock_irq(&lc->blocks_lock);
|
|
list_splice_init(&lc->unflushed_blocks, &block->list);
|
|
spin_unlock_irq(&lc->blocks_lock);
|
|
}
|
|
map_bio:
|
|
normal_map_bio(ti, bio);
|
|
return DM_MAPIO_REMAPPED;
|
|
}
|
|
|
|
static int normal_end_io(struct dm_target *ti, struct bio *bio,
|
|
blk_status_t *error)
|
|
{
|
|
struct log_writes_c *lc = ti->private;
|
|
struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
|
|
|
|
if (bio_data_dir(bio) == WRITE && pb->block) {
|
|
struct pending_block *block = pb->block;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&lc->blocks_lock, flags);
|
|
if (block->flags & LOG_FLUSH_FLAG) {
|
|
list_splice_tail_init(&block->list, &lc->logging_blocks);
|
|
list_add_tail(&block->list, &lc->logging_blocks);
|
|
wake_up_process(lc->log_kthread);
|
|
} else if (block->flags & LOG_FUA_FLAG) {
|
|
list_add_tail(&block->list, &lc->logging_blocks);
|
|
wake_up_process(lc->log_kthread);
|
|
} else
|
|
list_add_tail(&block->list, &lc->unflushed_blocks);
|
|
spin_unlock_irqrestore(&lc->blocks_lock, flags);
|
|
}
|
|
|
|
return DM_ENDIO_DONE;
|
|
}
|
|
|
|
/*
|
|
* INFO format: <logged entries> <highest allocated sector>
|
|
*/
|
|
static void log_writes_status(struct dm_target *ti, status_type_t type,
|
|
unsigned status_flags, char *result,
|
|
unsigned maxlen)
|
|
{
|
|
unsigned sz = 0;
|
|
struct log_writes_c *lc = ti->private;
|
|
|
|
switch (type) {
|
|
case STATUSTYPE_INFO:
|
|
DMEMIT("%llu %llu", lc->logged_entries,
|
|
(unsigned long long)lc->next_sector - 1);
|
|
if (!lc->logging_enabled)
|
|
DMEMIT(" logging_disabled");
|
|
break;
|
|
|
|
case STATUSTYPE_TABLE:
|
|
DMEMIT("%s %s", lc->dev->name, lc->logdev->name);
|
|
break;
|
|
|
|
case STATUSTYPE_IMA:
|
|
*result = '\0';
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int log_writes_prepare_ioctl(struct dm_target *ti,
|
|
struct block_device **bdev)
|
|
{
|
|
struct log_writes_c *lc = ti->private;
|
|
struct dm_dev *dev = lc->dev;
|
|
|
|
*bdev = dev->bdev;
|
|
/*
|
|
* Only pass ioctls through if the device sizes match exactly.
|
|
*/
|
|
if (ti->len != bdev_nr_sectors(dev->bdev))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static int log_writes_iterate_devices(struct dm_target *ti,
|
|
iterate_devices_callout_fn fn,
|
|
void *data)
|
|
{
|
|
struct log_writes_c *lc = ti->private;
|
|
|
|
return fn(ti, lc->dev, 0, ti->len, data);
|
|
}
|
|
|
|
/*
|
|
* Messages supported:
|
|
* mark <mark data> - specify the marked data.
|
|
*/
|
|
static int log_writes_message(struct dm_target *ti, unsigned argc, char **argv,
|
|
char *result, unsigned maxlen)
|
|
{
|
|
int r = -EINVAL;
|
|
struct log_writes_c *lc = ti->private;
|
|
|
|
if (argc != 2) {
|
|
DMWARN("Invalid log-writes message arguments, expect 2 arguments, got %d", argc);
|
|
return r;
|
|
}
|
|
|
|
if (!strcasecmp(argv[0], "mark"))
|
|
r = log_mark(lc, argv[1]);
|
|
else
|
|
DMWARN("Unrecognised log writes target message received: %s", argv[0]);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void log_writes_io_hints(struct dm_target *ti, struct queue_limits *limits)
|
|
{
|
|
struct log_writes_c *lc = ti->private;
|
|
struct request_queue *q = bdev_get_queue(lc->dev->bdev);
|
|
|
|
if (!q || !blk_queue_discard(q)) {
|
|
lc->device_supports_discard = false;
|
|
limits->discard_granularity = lc->sectorsize;
|
|
limits->max_discard_sectors = (UINT_MAX >> SECTOR_SHIFT);
|
|
}
|
|
limits->logical_block_size = bdev_logical_block_size(lc->dev->bdev);
|
|
limits->physical_block_size = bdev_physical_block_size(lc->dev->bdev);
|
|
limits->io_min = limits->physical_block_size;
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_FS_DAX)
|
|
static struct dax_device *log_writes_dax_pgoff(struct dm_target *ti,
|
|
pgoff_t *pgoff)
|
|
{
|
|
struct log_writes_c *lc = ti->private;
|
|
|
|
*pgoff += (get_start_sect(lc->dev->bdev) >> PAGE_SECTORS_SHIFT);
|
|
return lc->dev->dax_dev;
|
|
}
|
|
|
|
static long log_writes_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
|
|
long nr_pages, void **kaddr, pfn_t *pfn)
|
|
{
|
|
struct dax_device *dax_dev = log_writes_dax_pgoff(ti, &pgoff);
|
|
|
|
return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
|
|
}
|
|
|
|
static int log_writes_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
|
|
size_t nr_pages)
|
|
{
|
|
struct dax_device *dax_dev = log_writes_dax_pgoff(ti, &pgoff);
|
|
|
|
return dax_zero_page_range(dax_dev, pgoff, nr_pages << PAGE_SHIFT);
|
|
}
|
|
|
|
#else
|
|
#define log_writes_dax_direct_access NULL
|
|
#define log_writes_dax_zero_page_range NULL
|
|
#endif
|
|
|
|
static struct target_type log_writes_target = {
|
|
.name = "log-writes",
|
|
.version = {1, 1, 0},
|
|
.module = THIS_MODULE,
|
|
.ctr = log_writes_ctr,
|
|
.dtr = log_writes_dtr,
|
|
.map = log_writes_map,
|
|
.end_io = normal_end_io,
|
|
.status = log_writes_status,
|
|
.prepare_ioctl = log_writes_prepare_ioctl,
|
|
.message = log_writes_message,
|
|
.iterate_devices = log_writes_iterate_devices,
|
|
.io_hints = log_writes_io_hints,
|
|
.direct_access = log_writes_dax_direct_access,
|
|
.dax_zero_page_range = log_writes_dax_zero_page_range,
|
|
};
|
|
|
|
static int __init dm_log_writes_init(void)
|
|
{
|
|
int r = dm_register_target(&log_writes_target);
|
|
|
|
if (r < 0)
|
|
DMERR("register failed %d", r);
|
|
|
|
return r;
|
|
}
|
|
|
|
static void __exit dm_log_writes_exit(void)
|
|
{
|
|
dm_unregister_target(&log_writes_target);
|
|
}
|
|
|
|
module_init(dm_log_writes_init);
|
|
module_exit(dm_log_writes_exit);
|
|
|
|
MODULE_DESCRIPTION(DM_NAME " log writes target");
|
|
MODULE_AUTHOR("Josef Bacik <jbacik@fb.com>");
|
|
MODULE_LICENSE("GPL");
|