On completion of GET_FMAP message/response, setup the full famfs metadata such that it's possible to handle read/write/mmap directly to dax. Note that the devdax_iomap plumbing is not in yet...
* Add famfs_kfmap.h: in-memory structures for resolving famfs file maps (fmaps) to dax. * famfs.c: allocate, initialize and free fmaps * inode.c: only allow famfs mode if the fuse server has CAP_SYS_RAWIO * Update MAINTAINERS for the new files. Signed-off-by: John Groves <[email protected]> --- MAINTAINERS | 1 + fs/fuse/famfs.c | 355 +++++++++++++++++++++++++++++++++++++- fs/fuse/famfs_kfmap.h | 67 +++++++ fs/fuse/fuse_i.h | 22 ++- fs/fuse/inode.c | 21 ++- include/uapi/linux/fuse.h | 56 ++++++ 6 files changed, 510 insertions(+), 12 deletions(-) create mode 100644 fs/fuse/famfs_kfmap.h diff --git a/MAINTAINERS b/MAINTAINERS index 526309943026..16b0606a3b85 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10381,6 +10381,7 @@ L: [email protected] L: [email protected] S: Supported F: fs/fuse/famfs.c +F: fs/fuse/famfs_kfmap.h FUTEX SUBSYSTEM M: Thomas Gleixner <[email protected]> diff --git a/fs/fuse/famfs.c b/fs/fuse/famfs.c index 0f7e3f00e1e7..2aabd1d589fd 100644 --- a/fs/fuse/famfs.c +++ b/fs/fuse/famfs.c @@ -17,9 +17,355 @@ #include <linux/namei.h> #include <linux/string.h> +#include "famfs_kfmap.h" #include "fuse_i.h" +/***************************************************************************/ + +void +__famfs_meta_free(void *famfs_meta) +{ + struct famfs_file_meta *fmap = famfs_meta; + + if (!fmap) + return; + + if (fmap) { + switch (fmap->fm_extent_type) { + case SIMPLE_DAX_EXTENT: + kfree(fmap->se); + break; + case INTERLEAVED_EXTENT: + if (fmap->ie) + kfree(fmap->ie->ie_strips); + + kfree(fmap->ie); + break; + default: + pr_err("%s: invalid fmap type\n", __func__); + break; + } + } + kfree(fmap); +} + +static int +famfs_check_ext_alignment(struct famfs_meta_simple_ext *se) +{ + int errs = 0; + + if (se->dev_index != 0) + errs++; + + /* TODO: pass in alignment so we can support the other page sizes */ + if (!IS_ALIGNED(se->ext_offset, PMD_SIZE)) + errs++; + + if (!IS_ALIGNED(se->ext_len, PMD_SIZE)) + errs++; + + return errs; +} + +/** + * famfs_fuse_meta_alloc() - Allocate famfs file metadata + * @metap: Pointer to an mcache_map_meta pointer + * @ext_count: The number of extents needed + * + * Returns: 0=success + * -errno=failure + */ +static int +famfs_fuse_meta_alloc( + void *fmap_buf, + size_t fmap_buf_size, + struct famfs_file_meta **metap) +{ + struct famfs_file_meta *meta = NULL; + struct fuse_famfs_fmap_header *fmh; + size_t extent_total = 0; + size_t next_offset = 0; + int errs = 0; + int i, j; + int rc; + + fmh = (struct fuse_famfs_fmap_header *)fmap_buf; + + /* Move past fmh in fmap_buf */ + next_offset += sizeof(*fmh); + if (next_offset > fmap_buf_size) { + pr_err("%s:%d: fmap_buf underflow offset/size %ld/%ld\n", + __func__, __LINE__, next_offset, fmap_buf_size); + return -EINVAL; + } + + if (fmh->nextents < 1) { + pr_err("%s: nextents %d < 1\n", __func__, fmh->nextents); + return -EINVAL; + } + + if (fmh->nextents > FUSE_FAMFS_MAX_EXTENTS) { + pr_err("%s: nextents %d > max (%d) 1\n", + __func__, fmh->nextents, FUSE_FAMFS_MAX_EXTENTS); + return -E2BIG; + } + + meta = kzalloc(sizeof(*meta), GFP_KERNEL); + if (!meta) + return -ENOMEM; + + meta->error = false; + meta->file_type = fmh->file_type; + meta->file_size = fmh->file_size; + meta->fm_extent_type = fmh->ext_type; + + switch (fmh->ext_type) { + case FUSE_FAMFS_EXT_SIMPLE: { + struct fuse_famfs_simple_ext *se_in; + + se_in = (struct fuse_famfs_simple_ext *)(fmap_buf + next_offset); + + /* Move past simple extents */ + next_offset += fmh->nextents * sizeof(*se_in); + if (next_offset > fmap_buf_size) { + pr_err("%s:%d: fmap_buf underflow offset/size %ld/%ld\n", + __func__, __LINE__, next_offset, fmap_buf_size); + rc = -EINVAL; + goto errout; + } + + meta->fm_nextents = fmh->nextents; + + meta->se = kcalloc(meta->fm_nextents, sizeof(*(meta->se)), + GFP_KERNEL); + if (!meta->se) { + rc = -ENOMEM; + goto errout; + } + + if ((meta->fm_nextents > FUSE_FAMFS_MAX_EXTENTS) || + (meta->fm_nextents < 1)) { + rc = -EINVAL; + goto errout; + } + + for (i = 0; i < fmh->nextents; i++) { + meta->se[i].dev_index = se_in[i].se_devindex; + meta->se[i].ext_offset = se_in[i].se_offset; + meta->se[i].ext_len = se_in[i].se_len; + + /* Record bitmap of referenced daxdev indices */ + meta->dev_bitmap |= (1 << meta->se[i].dev_index); + + errs += famfs_check_ext_alignment(&meta->se[i]); + + extent_total += meta->se[i].ext_len; + } + break; + } + + case FUSE_FAMFS_EXT_INTERLEAVE: { + s64 size_remainder = meta->file_size; + struct fuse_famfs_iext *ie_in; + int niext = fmh->nextents; + + meta->fm_niext = niext; + + /* Allocate interleaved extent */ + meta->ie = kcalloc(niext, sizeof(*(meta->ie)), GFP_KERNEL); + if (!meta->ie) { + rc = -ENOMEM; + goto errout; + } + + /* + * Each interleaved extent has a simple extent list of strips. + * Outer loop is over separate interleaved extents + */ + for (i = 0; i < niext; i++) { + u64 nstrips; + struct fuse_famfs_simple_ext *sie_in; + + /* ie_in = one interleaved extent in fmap_buf */ + ie_in = (struct fuse_famfs_iext *) + (fmap_buf + next_offset); + + /* Move past one interleaved extent header in fmap_buf */ + next_offset += sizeof(*ie_in); + if (next_offset > fmap_buf_size) { + pr_err("%s:%d: fmap_buf underflow offset/size %ld/%ld\n", + __func__, __LINE__, next_offset, + fmap_buf_size); + rc = -EINVAL; + goto errout; + } + + nstrips = ie_in->ie_nstrips; + meta->ie[i].fie_chunk_size = ie_in->ie_chunk_size; + meta->ie[i].fie_nstrips = ie_in->ie_nstrips; + meta->ie[i].fie_nbytes = ie_in->ie_nbytes; + + if (!meta->ie[i].fie_nbytes) { + pr_err("%s: zero-length interleave!\n", + __func__); + rc = -EINVAL; + goto errout; + } + + /* sie_in = the strip extents in fmap_buf */ + sie_in = (struct fuse_famfs_simple_ext *) + (fmap_buf + next_offset); + + /* Move past strip extents in fmap_buf */ + next_offset += nstrips * sizeof(*sie_in); + if (next_offset > fmap_buf_size) { + pr_err("%s:%d: fmap_buf underflow offset/size %ld/%ld\n", + __func__, __LINE__, next_offset, + fmap_buf_size); + rc = -EINVAL; + goto errout; + } + + if ((nstrips > FUSE_FAMFS_MAX_STRIPS) || (nstrips < 1)) { + pr_err("%s: invalid nstrips=%lld (max=%d)\n", + __func__, nstrips, + FUSE_FAMFS_MAX_STRIPS); + errs++; + } + + /* Allocate strip extent array */ + meta->ie[i].ie_strips = kcalloc(ie_in->ie_nstrips, + sizeof(meta->ie[i].ie_strips[0]), + GFP_KERNEL); + if (!meta->ie[i].ie_strips) { + rc = -ENOMEM; + goto errout; + } + + /* Inner loop is over strips */ + for (j = 0; j < nstrips; j++) { + struct famfs_meta_simple_ext *strips_out; + u64 devindex = sie_in[j].se_devindex; + u64 offset = sie_in[j].se_offset; + u64 len = sie_in[j].se_len; + + strips_out = meta->ie[i].ie_strips; + strips_out[j].dev_index = devindex; + strips_out[j].ext_offset = offset; + strips_out[j].ext_len = len; + + /* Record bitmap of referenced daxdev indices */ + meta->dev_bitmap |= (1 << devindex); + + extent_total += len; + errs += famfs_check_ext_alignment(&strips_out[j]); + size_remainder -= len; + } + } + + if (size_remainder > 0) { + /* Sum of interleaved extent sizes is less than file size! */ + pr_err("%s: size_remainder %lld (0x%llx)\n", + __func__, size_remainder, size_remainder); + rc = -EINVAL; + goto errout; + } + break; + } + + default: + pr_err("%s: invalid ext_type %d\n", __func__, fmh->ext_type); + rc = -EINVAL; + goto errout; + } + + if (errs > 0) { + pr_err("%s: %d alignment errors found\n", __func__, errs); + rc = -EINVAL; + goto errout; + } + + /* More sanity checks */ + if (extent_total < meta->file_size) { + pr_err("%s: file size %ld larger than map size %ld\n", + __func__, meta->file_size, extent_total); + rc = -EINVAL; + goto errout; + } + + if (cmpxchg(metap, NULL, meta) != NULL) { + pr_debug("%s: fmap race detected\n", __func__); + rc = 0; /* fmap already installed */ + goto errout; + } + + return 0; +errout: + __famfs_meta_free(meta); + return rc; +} + +/** + * famfs_file_init_dax() - init famfs dax file metadata + * + * @fm: fuse_mount + * @inode: the inode + * @fmap_buf: fmap response message + * @fmap_size: Size of the fmap message + * + * Initialize famfs metadata for a file, based on the contents of the GET_FMAP + * response + * + * Return: 0=success + * -errno=failure + */ +int +famfs_file_init_dax( + struct fuse_mount *fm, + struct inode *inode, + void *fmap_buf, + size_t fmap_size) +{ + struct fuse_inode *fi = get_fuse_inode(inode); + struct famfs_file_meta *meta = NULL; + int rc = 0; + + if (fi->famfs_meta) { + pr_notice("%s: i_no=%ld fmap_size=%ld ALREADY INITIALIZED\n", + __func__, + inode->i_ino, fmap_size); + return 0; + } + + rc = famfs_fuse_meta_alloc(fmap_buf, fmap_size, &meta); + if (rc) + goto errout; + + /* Publish the famfs metadata on fi->famfs_meta */ + inode_lock(inode); + if (fi->famfs_meta) { + rc = -EEXIST; /* file already has famfs metadata */ + } else { + if (famfs_meta_set(fi, meta) != NULL) { + pr_debug("%s: file already had metadata\n", __func__); + __famfs_meta_free(meta); + /* rc is 0 - the file is valid */ + goto unlock_out; + } + i_size_write(inode, meta->file_size); + inode->i_flags |= S_DAX; + } + unlock_out: + inode_unlock(inode); + +errout: + if (rc) + __famfs_meta_free(meta); + + return rc; +} + #define FMAP_BUFSIZE PAGE_SIZE int @@ -63,12 +409,9 @@ fuse_get_fmap(struct fuse_mount *fm, struct inode *inode) } fmap_size = rc; - /* We retrieved the "fmap" (the file's map to memory), but - * we haven't used it yet. A call to famfs_file_init_dax() will be added - * here in a subsequent patch, when we add the ability to attach - * fmaps to files. - */ + /* Convert fmap into in-memory format and hang from inode */ + rc = famfs_file_init_dax(fm, inode, fmap_buf, fmap_size); kfree(fmap_buf); - return 0; + return rc; } diff --git a/fs/fuse/famfs_kfmap.h b/fs/fuse/famfs_kfmap.h new file mode 100644 index 000000000000..058645cb10a1 --- /dev/null +++ b/fs/fuse/famfs_kfmap.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * famfs - dax file system for shared fabric-attached memory + * + * Copyright 2023-2025 Micron Technology, Inc. + */ +#ifndef FAMFS_KFMAP_H +#define FAMFS_KFMAP_H + +/* + * The structures below are the in-memory metadata format for famfs files. + * Metadata retrieved via the GET_FMAP response is converted to this format + * for use in resolving file mapping faults. + * + * The GET_FMAP response contains the same information, but in a more + * message-and-versioning-friendly format. Those structs can be found in the + * famfs section of include/uapi/linux/fuse.h (aka fuse_kernel.h in libfuse) + */ + +enum famfs_file_type { + FAMFS_REG, + FAMFS_SUPERBLOCK, + FAMFS_LOG, +}; + +/* We anticipate the possibility of supporting additional types of extents */ +enum famfs_extent_type { + SIMPLE_DAX_EXTENT, + INTERLEAVED_EXTENT, + INVALID_EXTENT_TYPE, +}; + +struct famfs_meta_simple_ext { + u64 dev_index; + u64 ext_offset; + u64 ext_len; +}; + +struct famfs_meta_interleaved_ext { + u64 fie_nstrips; + u64 fie_chunk_size; + u64 fie_nbytes; + struct famfs_meta_simple_ext *ie_strips; +}; + +/* + * Each famfs dax file has this hanging from its fuse_inode->famfs_meta + */ +struct famfs_file_meta { + bool error; + enum famfs_file_type file_type; + size_t file_size; + enum famfs_extent_type fm_extent_type; + u64 dev_bitmap; /* bitmap of referenced daxdevs by index */ + union { /* This will make code a bit more readable */ + struct { + size_t fm_nextents; + struct famfs_meta_simple_ext *se; + }; + struct { + size_t fm_niext; + struct famfs_meta_interleaved_ext *ie; + }; + }; +}; + +#endif /* FAMFS_KFMAP_H */ diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 691c7850cf4e..f9e920e95baf 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -1658,6 +1658,12 @@ extern void fuse_sysctl_unregister(void); /* famfs.c */ +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) +int famfs_file_init_dax(struct fuse_mount *fm, + struct inode *inode, void *fmap_buf, + size_t fmap_size); +void __famfs_meta_free(void *map); +#endif static inline void famfs_teardown(struct fuse_conn *fc) { #if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) @@ -1665,11 +1671,18 @@ static inline void famfs_teardown(struct fuse_conn *fc) #endif } +static inline void famfs_meta_init(struct fuse_inode *fi) +{ +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) + fi->famfs_meta = NULL; +#endif +} + static inline struct fuse_backing *famfs_meta_set(struct fuse_inode *fi, void *meta) { #if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) - return xchg(&fi->famfs_meta, meta); + return cmpxchg(&fi->famfs_meta, NULL, meta); #else return NULL; #endif @@ -1677,7 +1690,12 @@ static inline struct fuse_backing *famfs_meta_set(struct fuse_inode *fi, static inline void famfs_meta_free(struct fuse_inode *fi) { - /* Stub wil be connected in a subsequent commit */ +#if IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) + if (fi->famfs_meta != NULL) { + __famfs_meta_free(fi->famfs_meta); + famfs_meta_set(fi, NULL); + } +#endif } static inline int fuse_file_famfs(struct fuse_inode *fi) diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 9e121a1d63b7..391ead26bfa2 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -121,7 +121,7 @@ static struct inode *fuse_alloc_inode(struct super_block *sb) fuse_inode_backing_set(fi, NULL); if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX)) - famfs_meta_set(fi, NULL); + famfs_meta_init(fi); return &fi->inode; @@ -1485,8 +1485,21 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, timeout = arg->request_timeout; if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) && - flags & FUSE_DAX_FMAP) - fc->famfs_iomap = 1; + flags & FUSE_DAX_FMAP) { + /* famfs_iomap is only allowed if the fuse + * server has CAP_SYS_RAWIO. This was checked + * in fuse_send_init, and FUSE_DAX_IOMAP was + * set in in_flags if so. Only allow enablement + * if we find it there. This function is + * normally not running in fuse server context, + * so we can do the capability check here... + */ + u64 in_flags = ((u64)ia->in.flags2 << 32) + | ia->in.flags; + + if (in_flags & FUSE_DAX_FMAP) + fc->famfs_iomap = 1; + } } else { ra_pages = fc->max_read / PAGE_SIZE; fc->no_lock = 1; @@ -1548,7 +1561,7 @@ static struct fuse_init_args *fuse_new_init(struct fuse_mount *fm) flags |= FUSE_SUBMOUNTS; if (IS_ENABLED(CONFIG_FUSE_PASSTHROUGH)) flags |= FUSE_PASSTHROUGH; - if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX)) + if (IS_ENABLED(CONFIG_FUSE_FAMFS_DAX) && capable(CAP_SYS_RAWIO)) flags |= FUSE_DAX_FMAP; /* diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h index bfb92a4aa8a9..e6dd3c24bb11 100644 --- a/include/uapi/linux/fuse.h +++ b/include/uapi/linux/fuse.h @@ -243,6 +243,13 @@ * * 7.46 * - Add FUSE_DAX_FMAP capability - ability to handle in-kernel fsdax maps + * - Add the following structures for the GET_FMAP message reply components: + * - struct fuse_famfs_simple_ext + * - struct fuse_famfs_iext + * - struct fuse_famfs_fmap_header + * - Add the following enumerated types + * - enum fuse_famfs_file_type + * - enum famfs_ext_type */ #ifndef _LINUX_FUSE_H @@ -1318,6 +1325,55 @@ struct fuse_uring_cmd_req { /* Famfs fmap message components */ +#define FAMFS_FMAP_VERSION 1 + #define FAMFS_FMAP_MAX 32768 /* Largest supported fmap message */ +#define FUSE_FAMFS_MAX_EXTENTS 32 +#define FUSE_FAMFS_MAX_STRIPS 32 + +enum fuse_famfs_file_type { + FUSE_FAMFS_FILE_REG, + FUSE_FAMFS_FILE_SUPERBLOCK, + FUSE_FAMFS_FILE_LOG, +}; + +enum famfs_ext_type { + FUSE_FAMFS_EXT_SIMPLE = 0, + FUSE_FAMFS_EXT_INTERLEAVE = 1, +}; + +struct fuse_famfs_simple_ext { + uint32_t se_devindex; + uint32_t reserved; + uint64_t se_offset; + uint64_t se_len; +}; + +struct fuse_famfs_iext { /* Interleaved extent */ + uint32_t ie_nstrips; + uint32_t ie_chunk_size; + uint64_t ie_nbytes; /* Total bytes for this interleaved_ext; + * sum of strips may be more + */ + uint64_t reserved; +}; + +struct fuse_famfs_fmap_header { + uint8_t file_type; /* enum famfs_file_type */ + uint8_t reserved; + uint16_t fmap_version; + uint32_t ext_type; /* enum famfs_log_ext_type */ + uint32_t nextents; + uint32_t reserved0; + uint64_t file_size; + uint64_t reserved1; +}; + +static inline int32_t fmap_msg_min_size(void) +{ + /* Smallest fmap message is a header plus one simple extent */ + return (sizeof(struct fuse_famfs_fmap_header) + + sizeof(struct fuse_famfs_simple_ext)); +} #endif /* _LINUX_FUSE_H */ -- 2.49.0
