From: Christoph Hellwig Date: Thu, 23 Apr 2026 18:18:54 +0000 (-0400) Subject: exportfs,nfsd: rework checking for layout-based block device access support X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=da9baa5470dcb077a7c9806f0925c60b530c470b;p=thirdparty%2Fkernel%2Flinux.git exportfs,nfsd: rework checking for layout-based block device access support Currently NFSD hard codes checking support for block-style layouts. Lift the checks into a file system-helper and provide a exportfs-level helper to implement the typical checks. This prepares for supporting block layout export of multiple devices per file system. Signed-off-by: Christoph Hellwig Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever Link: https://patch.msgid.link/20260423181854.743150-5-cel@kernel.org Signed-off-by: Christian Brauner --- diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c index 665153f1720e0..35fef3197a66f 100644 --- a/fs/nfsd/export.c +++ b/fs/nfsd/export.c @@ -735,7 +735,8 @@ static int svc_export_parse(struct cache_detail *cd, char *mesg, int mlen) goto out4; err = 0; - nfsd4_setup_layout_type(&exp); + if (exp.ex_flags & NFSEXP_PNFS) + nfsd4_setup_layout_type(&exp); } expp = svc_export_lookup(&exp); diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c index cf5b7eb417c5c..c3543d4567024 100644 --- a/fs/nfsd/nfs4layouts.c +++ b/fs/nfsd/nfs4layouts.c @@ -2,7 +2,6 @@ /* * Copyright (c) 2014 Christoph Hellwig. */ -#include #include #include #include @@ -128,28 +127,17 @@ nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp, void nfsd4_setup_layout_type(struct svc_export *exp) { -#if defined(CONFIG_NFSD_BLOCKLAYOUT) || defined(CONFIG_NFSD_SCSILAYOUT) struct super_block *sb = exp->ex_path.mnt->mnt_sb; - const struct exportfs_block_ops *bops = sb->s_export_op->block_ops; -#endif - - if (!(exp->ex_flags & NFSEXP_PNFS)) - return; + expfs_block_layouts_t block_supported = exportfs_layouts_supported(sb); -#ifdef CONFIG_NFSD_FLEXFILELAYOUT - exp->ex_layout_types |= 1 << LAYOUT_FLEX_FILES; -#endif -#ifdef CONFIG_NFSD_BLOCKLAYOUT - if (bops && bops->get_uuid && bops->map_blocks && bops->commit_blocks) + if (IS_ENABLED(CONFIG_NFSD_FLEXFILELAYOUT)) + exp->ex_layout_types |= 1 << LAYOUT_FLEX_FILES; + if (IS_ENABLED(CONFIG_NFSD_BLOCKLAYOUT) && + (block_supported & EXPFS_BLOCK_IN_BAND_ID)) exp->ex_layout_types |= 1 << LAYOUT_BLOCK_VOLUME; -#endif -#ifdef CONFIG_NFSD_SCSILAYOUT - if (bops && bops->map_blocks && bops->commit_blocks && - sb->s_bdev && - sb->s_bdev->bd_disk->fops->pr_ops && - sb->s_bdev->bd_disk->fops->get_unique_id) + if (IS_ENABLED(CONFIG_NFSD_SCSILAYOUT) && + (block_supported & EXPFS_BLOCK_OUT_OF_BAND_ID)) exp->ex_layout_types |= 1 << LAYOUT_SCSI; -#endif } void nfsd4_close_layout(struct nfs4_layout_stateid *ls) diff --git a/fs/xfs/xfs_pnfs.c b/fs/xfs/xfs_pnfs.c index 7d689bb2efd91..266a07601e8d0 100644 --- a/fs/xfs/xfs_pnfs.c +++ b/fs/xfs/xfs_pnfs.c @@ -13,6 +13,7 @@ #include "xfs_bmap.h" #include "xfs_iomap.h" #include "xfs_pnfs.h" +#include /* * Ensure that we do not have any outstanding pNFS layouts that can be used by @@ -45,6 +46,17 @@ xfs_break_leased_layouts( return error; } +static expfs_block_layouts_t +xfs_fs_layouts_supported( + struct super_block *sb) +{ + expfs_block_layouts_t supported = EXPFS_BLOCK_IN_BAND_ID; + + if (exportfs_bdev_supports_out_of_band_id(sb->s_bdev)) + supported |= EXPFS_BLOCK_OUT_OF_BAND_ID; + return supported; +} + /* * Get a unique ID including its location so that the client can identify * the exported device. @@ -335,6 +347,7 @@ out_drop_iolock: } const struct exportfs_block_ops xfs_export_block_ops = { + .layouts_supported = xfs_fs_layouts_supported, .get_uuid = xfs_fs_get_uuid, .map_blocks = xfs_fs_map_blocks, .commit_blocks = xfs_fs_commit_blocks, diff --git a/include/linux/exportfs_block.h b/include/linux/exportfs_block.h index d1dec4689b14a..de519b7b599b3 100644 --- a/include/linux/exportfs_block.h +++ b/include/linux/exportfs_block.h @@ -7,13 +7,35 @@ #ifndef LINUX_EXPORTFS_BLOCK_H #define LINUX_EXPORTFS_BLOCK_H 1 -#include +#include +#include +#include struct inode; struct iomap; struct super_block; +/* + * There are the two types of block-style layout support: + * - In-band implies a device identified by a unique cookie inside the actual + * device address space checked by the ->get_uuid method as used by the pNFS + * block layout. This is a bit dangerous and deprecated. + * - Out of band implies identification by out of band unique identifiers + * specified by the storage protocol, which is much safer and used by the + * pNFS SCSI/NVMe layouts. + */ +typedef unsigned int __bitwise expfs_block_layouts_t; +#define EXPFS_BLOCK_FLAG(__bit) \ + ((__force expfs_block_layouts_t)(1u << __bit)) +#define EXPFS_BLOCK_IN_BAND_ID EXPFS_BLOCK_FLAG(0) +#define EXPFS_BLOCK_OUT_OF_BAND_ID EXPFS_BLOCK_FLAG(1) + struct exportfs_block_ops { + /* + * Returns the EXPFS_BLOCK_* bitmap of supported layout types. + */ + expfs_block_layouts_t (*layouts_supported)(struct super_block *sb); + /* * Get the in-band device unique signature exposed to clients. */ @@ -35,4 +57,32 @@ struct exportfs_block_ops { int nr_iomaps, loff_t new_size); }; +static inline bool +exportfs_bdev_supports_out_of_band_id(struct block_device *bdev) +{ + return bdev->bd_disk->fops->pr_ops && + bdev->bd_disk->fops->get_unique_id; +} + +#ifdef CONFIG_EXPORTFS_BLOCK_OPS +static inline expfs_block_layouts_t +exportfs_layouts_supported(struct super_block *sb) +{ + const struct exportfs_block_ops *bops = sb->s_export_op->block_ops; + + if (!bops || + !bops->layouts_supported || + WARN_ON_ONCE(!bops->map_blocks) || + WARN_ON_ONCE(!bops->commit_blocks)) + return 0; + return bops->layouts_supported(sb); +} +#else +static inline expfs_block_layouts_t +exportfs_layouts_supported(struct super_block *sb) +{ + return 0; +} +#endif /* CONFIG_EXPORTFS_BLOCK_OPS */ + #endif /* LINUX_EXPORTFS_BLOCK_H */