diff options
Diffstat (limited to 'fs/nfsd/blocklayout.c')
| -rw-r--r-- | fs/nfsd/blocklayout.c | 526 |
1 files changed, 526 insertions, 0 deletions
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c new file mode 100644 index 000000000..5be7721c2 --- /dev/null +++ b/fs/nfsd/blocklayout.c @@ -0,0 +1,526 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2014-2016 Christoph Hellwig. + */ +#include <linux/exportfs_block.h> +#include <linux/iomap.h> +#include <linux/slab.h> +#include <linux/pr.h> + +#include <linux/nfsd/debug.h> + +#include "blocklayoutxdr.h" +#include "pnfs.h" +#include "filecache.h" +#include "vfs.h" +#include "trace.h" + +#define NFSDDBG_FACILITY NFSDDBG_PNFS + + +/* + * Get an extent from the file system that starts at offset or below + * and may be shorter than the requested length. + */ +static __be32 +nfsd4_block_map_extent(struct inode *inode, const struct svc_fh *fhp, + u64 offset, u64 length, u32 iomode, u64 minlength, + struct pnfs_block_extent *bex) +{ + struct super_block *sb = inode->i_sb; + struct iomap iomap; + u32 device_generation = 0; + int error; + + error = sb->s_export_op->block_ops->map_blocks(inode, offset, length, + &iomap, iomode != IOMODE_READ, &device_generation); + if (error) { + if (error == -ENXIO) + return nfserr_layoutunavailable; + return nfserrno(error); + } + + switch (iomap.type) { + case IOMAP_MAPPED: + if (iomode == IOMODE_READ) + bex->es = PNFS_BLOCK_READ_DATA; + else + bex->es = PNFS_BLOCK_READWRITE_DATA; + bex->soff = iomap.addr; + break; + case IOMAP_UNWRITTEN: + if (iomode & IOMODE_RW) { + /* + * Crack monkey special case from section 2.3.1. + */ + if (minlength == 0) { + dprintk("pnfsd: no soup for you!\n"); + return nfserr_layoutunavailable; + } + + bex->es = PNFS_BLOCK_INVALID_DATA; + bex->soff = iomap.addr; + break; + } + fallthrough; + case IOMAP_HOLE: + if (iomode == IOMODE_READ) { + bex->es = PNFS_BLOCK_NONE_DATA; + break; + } + fallthrough; + case IOMAP_DELALLOC: + default: + WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type); + return nfserr_layoutunavailable; + } + + error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation); + if (error) + return nfserrno(error); + + bex->foff = iomap.offset; + bex->len = iomap.length; + return nfs_ok; +} + +static __be32 +nfsd4_block_proc_layoutget(struct svc_rqst *rqstp, struct inode *inode, + const struct svc_fh *fhp, struct nfsd4_layoutget *args) +{ + struct nfsd4_layout_seg *seg = &args->lg_seg; + struct pnfs_block_layout *bl; + struct pnfs_block_extent *first_bex, *last_bex; + u64 offset = seg->offset, length = seg->length; + u32 i, nr_extents_max, block_size = i_blocksize(inode); + __be32 nfserr; + + if (locks_in_grace(SVC_NET(rqstp))) + return nfserr_grace; + + nfserr = nfserr_layoutunavailable; + if (seg->offset & (block_size - 1)) { + dprintk("pnfsd: I/O misaligned\n"); + goto out_error; + } + + /* + * RFC 8881, section 3.3.17: + * The layout4 data type defines a layout for a file. + * + * RFC 8881, section 18.43.3: + * The loga_maxcount field specifies the maximum layout size + * (in bytes) that the client can handle. If the size of the + * layout structure exceeds the size specified by maxcount, + * the metadata server will return the NFS4ERR_TOOSMALL error. + */ + nfserr = nfserr_toosmall; + if (args->lg_maxcount < PNFS_BLOCK_LAYOUT4_SIZE + + PNFS_BLOCK_EXTENT_SIZE) + goto out_error; + + /* + * Limit the maximum layout size to avoid allocating + * a large buffer on the server for each layout request. + */ + nr_extents_max = (min(args->lg_maxcount, PAGE_SIZE) - + PNFS_BLOCK_LAYOUT4_SIZE) / PNFS_BLOCK_EXTENT_SIZE; + + /* + * Some clients barf on non-zero block numbers for NONE or INVALID + * layouts, so make sure to zero the whole structure. + */ + nfserr = nfserrno(-ENOMEM); + bl = kzalloc_flex(*bl, extents, nr_extents_max); + if (!bl) + goto out_error; + bl->nr_extents = nr_extents_max; + args->lg_content = bl; + + for (i = 0; i < bl->nr_extents; i++) { + struct pnfs_block_extent *bex = bl->extents + i; + u64 bex_length; + + nfserr = nfsd4_block_map_extent(inode, fhp, offset, length, + seg->iomode, args->lg_minlength, bex); + if (nfserr != nfs_ok) + goto out_error; + + bex_length = bex->len - (offset - bex->foff); + if (bex_length >= length) { + bl->nr_extents = i + 1; + break; + } + + offset = bex->foff + bex->len; + length -= bex_length; + } + + first_bex = bl->extents; + last_bex = bl->extents + bl->nr_extents - 1; + + nfserr = nfserr_layoutunavailable; + length = last_bex->foff + last_bex->len - seg->offset; + if (length < args->lg_minlength) { + dprintk("pnfsd: extent smaller than minlength\n"); + goto out_error; + } + + seg->offset = first_bex->foff; + seg->length = last_bex->foff - first_bex->foff + last_bex->len; + return nfs_ok; + +out_error: + seg->length = 0; + return nfserr; +} + +static __be32 +nfsd4_block_commit_blocks(struct inode *inode, struct nfsd4_layoutcommit *lcp, + struct iomap *iomaps, int nr_iomaps) +{ + int error; + + /* + * This ignores the client provided mtime in loca_time_modify, as a + * fully client specified mtime doesn't really fit into the Linux + * multi-grain timestamp architecture. + * + * RFC 8881 Section 18.42 makes it clear that the client provided + * timestamp is a "may" condition, and clients that want to force a + * specific timestamp should send a separate SETATTR in the compound. + */ + error = inode->i_sb->s_export_op->block_ops->commit_blocks(inode, + iomaps, nr_iomaps, + lcp->lc_size_chg ? lcp->lc_newsize : 0); + kfree(iomaps); + return nfserrno(error); +} + +#ifdef CONFIG_NFSD_BLOCKLAYOUT +static int +nfsd4_block_get_device_info_simple(struct super_block *sb, + struct nfsd4_getdeviceinfo *gdp) +{ + struct pnfs_block_deviceaddr *dev; + struct pnfs_block_volume *b; + + dev = kzalloc_flex(*dev, volumes, 1); + if (!dev) + return -ENOMEM; + gdp->gd_device = dev; + + dev->nr_volumes = 1; + b = &dev->volumes[0]; + + b->type = PNFS_BLOCK_VOLUME_SIMPLE; + b->simple.sig_len = PNFS_BLOCK_UUID_LEN; + return sb->s_export_op->block_ops->get_uuid(sb, b->simple.sig, + &b->simple.sig_len, &b->simple.offset); +} + +static __be32 +nfsd4_block_proc_getdeviceinfo(struct super_block *sb, + struct svc_rqst *rqstp, + struct nfs4_client *clp, + struct nfsd4_getdeviceinfo *gdp) +{ + if (bdev_is_partition(sb->s_bdev)) + return nfserr_inval; + return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp)); +} + +static __be32 +nfsd4_block_proc_layoutcommit(struct inode *inode, struct svc_rqst *rqstp, + struct nfsd4_layoutcommit *lcp) +{ + struct iomap *iomaps; + int nr_iomaps; + __be32 nfserr; + + rqstp->rq_arg = lcp->lc_up_layout; + svcxdr_init_decode(rqstp); + + nfserr = nfsd4_block_decode_layoutupdate(&rqstp->rq_arg_stream, + &iomaps, &nr_iomaps, i_blocksize(inode)); + if (nfserr != nfs_ok) + return nfserr; + + return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps); +} + +const struct nfsd4_layout_ops bl_layout_ops = { + /* + * Pretend that we send notification to the client. This is a blatant + * lie to force recent Linux clients to cache our device IDs. + * We rarely ever change the device ID, so the harm of leaking deviceids + * for a while isn't too bad. Unfortunately RFC5661 is a complete mess + * in this regard, but I filed errata 4119 for this a while ago, and + * hopefully the Linux client will eventually start caching deviceids + * without this again. + */ + .notify_types = + NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE, + .proc_getdeviceinfo = nfsd4_block_proc_getdeviceinfo, + .encode_getdeviceinfo = nfsd4_block_encode_getdeviceinfo, + .proc_layoutget = nfsd4_block_proc_layoutget, + .encode_layoutget = nfsd4_block_encode_layoutget, + .proc_layoutcommit = nfsd4_block_proc_layoutcommit, +}; +#endif /* CONFIG_NFSD_BLOCKLAYOUT */ + +#ifdef CONFIG_NFSD_SCSILAYOUT + +#define NFSD_MDS_PR_FENCED XA_MARK_0 + +/* + * Clear the fence flag if the device already has an entry. This occurs + * when a client re-registers after a previous fence, allowing new + * layouts for this device. + * + * Insert only on first registration. This bounds cl_dev_fences to the + * count of devices this client has accessed, preventing unbounded growth. + */ +static inline int nfsd4_scsi_fence_insert(struct nfs4_client *clp, + dev_t device) +{ + struct xarray *xa = &clp->cl_dev_fences; + int ret; + + xa_lock(xa); + ret = __xa_insert(xa, device, XA_ZERO_ENTRY, GFP_KERNEL); + if (ret == -EBUSY) { + __xa_clear_mark(xa, device, NFSD_MDS_PR_FENCED); + ret = 0; + } + xa_unlock(xa); + clp->cl_fence_retry_warn = false; + return ret; +} + +static inline bool nfsd4_scsi_fence_set(struct nfs4_client *clp, dev_t device) +{ + struct xarray *xa = &clp->cl_dev_fences; + bool skip; + + xa_lock(xa); + skip = xa_get_mark(xa, device, NFSD_MDS_PR_FENCED); + if (!skip) + __xa_set_mark(xa, device, NFSD_MDS_PR_FENCED); + xa_unlock(xa); + return skip; +} + +static inline void nfsd4_scsi_fence_clear(struct nfs4_client *clp, dev_t device) +{ + xa_clear_mark(&clp->cl_dev_fences, device, NFSD_MDS_PR_FENCED); +} + +#define NFSD_MDS_PR_KEY 0x0100000000000000ULL + +/* + * We use the client ID as a unique key for the reservations. + * This allows us to easily fence a client when recalls fail. + */ +static u64 nfsd4_scsi_pr_key(struct nfs4_client *clp) +{ + return ((u64)clp->cl_clientid.cl_boot << 32) | clp->cl_clientid.cl_id; +} + +static const u8 designator_types[] = { + PS_DESIGNATOR_EUI64, + PS_DESIGNATOR_NAA, +}; + +static int +nfsd4_block_get_unique_id(struct gendisk *disk, struct pnfs_block_volume *b) +{ + int ret, i; + + for (i = 0; i < ARRAY_SIZE(designator_types); i++) { + u8 type = designator_types[i]; + + ret = disk->fops->get_unique_id(disk, b->scsi.designator, type); + if (ret > 0) { + b->scsi.code_set = PS_CODE_SET_BINARY; + b->scsi.designator_type = type; + b->scsi.designator_len = ret; + return 0; + } + } + + return -EINVAL; +} + +static int +nfsd4_block_get_device_info_scsi(struct super_block *sb, + struct nfs4_client *clp, + struct nfsd4_getdeviceinfo *gdp) +{ + struct pnfs_block_deviceaddr *dev; + struct pnfs_block_volume *b; + const struct pr_ops *ops; + int ret; + + dev = kzalloc_flex(*dev, volumes, 1); + if (!dev) + return -ENOMEM; + gdp->gd_device = dev; + + dev->nr_volumes = 1; + b = &dev->volumes[0]; + + b->type = PNFS_BLOCK_VOLUME_SCSI; + b->scsi.pr_key = nfsd4_scsi_pr_key(clp); + + ret = nfsd4_block_get_unique_id(sb->s_bdev->bd_disk, b); + if (ret < 0) + goto out_free_dev; + + ret = -EINVAL; + ops = sb->s_bdev->bd_disk->fops->pr_ops; + if (!ops) { + pr_err("pNFS: device %s does not support PRs.\n", + sb->s_id); + goto out_free_dev; + } + + ret = nfsd4_scsi_fence_insert(clp, sb->s_bdev->bd_dev); + if (ret < 0) + goto out_free_dev; + + ret = ops->pr_register(sb->s_bdev, 0, NFSD_MDS_PR_KEY, true); + if (ret) { + pr_err("pNFS: failed to register key for device %s.\n", + sb->s_id); + goto out_free_dev; + } + + ret = ops->pr_reserve(sb->s_bdev, NFSD_MDS_PR_KEY, + PR_EXCLUSIVE_ACCESS_REG_ONLY, 0); + if (ret) { + pr_err("pNFS: failed to reserve device %s.\n", + sb->s_id); + goto out_free_dev; + } + + return 0; + +out_free_dev: + kfree(dev); + gdp->gd_device = NULL; + return ret; +} + +static __be32 +nfsd4_scsi_proc_getdeviceinfo(struct super_block *sb, + struct svc_rqst *rqstp, + struct nfs4_client *clp, + struct nfsd4_getdeviceinfo *gdp) +{ + if (bdev_is_partition(sb->s_bdev)) + return nfserr_inval; + return nfserrno(nfsd4_block_get_device_info_scsi(sb, clp, gdp)); +} +static __be32 +nfsd4_scsi_proc_layoutcommit(struct inode *inode, struct svc_rqst *rqstp, + struct nfsd4_layoutcommit *lcp) +{ + struct iomap *iomaps; + int nr_iomaps; + __be32 nfserr; + + rqstp->rq_arg = lcp->lc_up_layout; + svcxdr_init_decode(rqstp); + + nfserr = nfsd4_scsi_decode_layoutupdate(&rqstp->rq_arg_stream, + &iomaps, &nr_iomaps, i_blocksize(inode)); + if (nfserr != nfs_ok) + return nfserr; + + return nfsd4_block_commit_blocks(inode, lcp, iomaps, nr_iomaps); +} + +/* + * Perform the fence operation to prevent the client from accessing the + * block device. If a fence operation is already in progress, wait for + * it to complete before checking the NFSD_MDS_PR_FENCED flag. Once the + * operation is complete, check the flag. If NFSD_MDS_PR_FENCED is set, + * update the layout stateid by setting the ls_fenced flag to indicate + * that the client has been fenced. + * + * The cl_fence_mutex ensures that the fence operation has been fully + * completed, rather than just in progress, when returning from this + * function. + * + * Return true if client was fenced otherwise return false. + */ +static bool +nfsd4_scsi_fence_client(struct nfs4_layout_stateid *ls, struct nfsd_file *file) +{ + struct nfs4_client *clp = ls->ls_stid.sc_client; + struct block_device *bdev = file->nf_file->f_path.mnt->mnt_sb->s_bdev; + int status; + bool ret; + + mutex_lock(&clp->cl_fence_mutex); + if (nfsd4_scsi_fence_set(clp, bdev->bd_dev)) { + mutex_unlock(&clp->cl_fence_mutex); + return true; + } + + status = bdev->bd_disk->fops->pr_ops->pr_preempt(bdev, NFSD_MDS_PR_KEY, + nfsd4_scsi_pr_key(clp), + PR_EXCLUSIVE_ACCESS_REG_ONLY, true); + /* + * Reset to allow retry only when the command could not have + * reached the device. Negative status means a local error + * (e.g., -ENOMEM) prevented the command from being sent. + * PR_STS_PATH_FAILED, PR_STS_PATH_FAST_FAILED, and + * PR_STS_RETRY_PATH_FAILURE indicate transport path failures + * before device delivery. + * + * For all other errors, the command may have reached the device + * and the preempt may have succeeded. Avoid resetting, since + * retrying a successful preempt returns PR_STS_IOERR or + * PR_STS_RESERVATION_CONFLICT, which would cause an infinite + * retry loop. + */ + switch (status) { + case 0: + case PR_STS_IOERR: + case PR_STS_RESERVATION_CONFLICT: + ret = true; + break; + default: + /* retry-able and other errors */ + ret = false; + nfsd4_scsi_fence_clear(clp, bdev->bd_dev); + break; + } + mutex_unlock(&clp->cl_fence_mutex); + + trace_nfsd_pnfs_fence(clp, bdev->bd_disk->disk_name, status); + return ret; +} + +const struct nfsd4_layout_ops scsi_layout_ops = { + /* + * Pretend that we send notification to the client. This is a blatant + * lie to force recent Linux clients to cache our device IDs. + * We rarely ever change the device ID, so the harm of leaking deviceids + * for a while isn't too bad. Unfortunately RFC5661 is a complete mess + * in this regard, but I filed errata 4119 for this a while ago, and + * hopefully the Linux client will eventually start caching deviceids + * without this again. + */ + .notify_types = + NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE, + .proc_getdeviceinfo = nfsd4_scsi_proc_getdeviceinfo, + .encode_getdeviceinfo = nfsd4_block_encode_getdeviceinfo, + .proc_layoutget = nfsd4_block_proc_layoutget, + .encode_layoutget = nfsd4_block_encode_layoutget, + .proc_layoutcommit = nfsd4_scsi_proc_layoutcommit, + .fence_client = nfsd4_scsi_fence_client, +}; +#endif /* CONFIG_NFSD_SCSILAYOUT */ |