From: Amir Goldstein <amir73il@gmail.com> mainline inclusion from mainline-v6.9-rc1 commit fc8ff397b2a91590031ae08534de627f957005cb category: feature bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBHLU4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- In preparation for opening file in passthrough mode, store the fuse_open_out argument in ff->args to be passed into fuse_file_io_open() with the optional backing_id member. This will be used for setting up passthrough to backing file on open reply with FOPEN_PASSTHROUGH flag and a valid backing_id. Opening a file in passthrough mode may fail for several reasons, such as missing capability, conflicting open flags or inode in caching mode. Return EIO from fuse_file_io_open() in those cases. The combination of FOPEN_PASSTHROUGH and FOPEN_DIRECT_IO is allowed - it mean that read/write operations will go directly to the server, but mmap will be done to the backing file. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- fs/fuse/fuse_i.h | 19 ++++++++++++++++--- fs/fuse/dir.c | 12 +++++++----- fs/fuse/file.c | 34 +++++++++++++++------------------- fs/fuse/iomode.c | 44 ++++++++++++++++++++++++++++++++++++++++---- 4 files changed, 78 insertions(+), 31 deletions(-) diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 4d9a14db696b..2168846050a3 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -216,15 +216,15 @@ enum { struct fuse_conn; struct fuse_mount; -struct fuse_release_args; +union fuse_file_args; /** FUSE specific file data */ struct fuse_file { /** Fuse connection for this file */ struct fuse_mount *fm; - /* Argument space reserved for release */ - struct fuse_release_args *release_args; + /* Argument space reserved for open/release */ + union fuse_file_args *args; /** Kernel file handle guaranteed to be unique */ u64 kh; @@ -326,6 +326,19 @@ struct fuse_args_pages { unsigned int num_pages; }; +struct fuse_release_args { + struct fuse_args args; + struct fuse_release_in inarg; + struct inode *inode; +}; + +union fuse_file_args { + /* Used during open() */ + struct fuse_open_out open_outarg; + /* Used during release() */ + struct fuse_release_args release_args; +}; + #define FUSE_ARGS(args) struct fuse_args args = {} /** The request IO state (for asynchronous processing) */ diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index ca865e7c4b55..1ca3d3643d55 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -619,7 +619,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, FUSE_ARGS(args); struct fuse_forget_link *forget; struct fuse_create_in inarg; - struct fuse_open_out outopen; + struct fuse_open_out *outopenp; struct fuse_entry_out outentry; struct fuse_inode *fi; struct fuse_file *ff; @@ -663,8 +663,10 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, args.out_numargs = 2; args.out_args[0].size = sizeof(outentry); args.out_args[0].value = &outentry; - args.out_args[1].size = sizeof(outopen); - args.out_args[1].value = &outopen; + /* Store outarg for fuse_finish_open() */ + outopenp = &ff->args->open_outarg; + args.out_args[1].size = sizeof(*outopenp); + args.out_args[1].value = outopenp; err = get_create_ext(&args, dir, entry, mode); if (err) @@ -680,9 +682,9 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, fuse_invalid_attr(&outentry.attr)) goto out_free_ff; - ff->fh = outopen.fh; + ff->fh = outopenp->fh; ff->nodeid = outentry.nodeid; - ff->open_flags = outopen.open_flags; + ff->open_flags = outopenp->open_flags; inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation, &outentry.attr, ATTR_TIMEOUT(&outentry), 0); if (!inode) { diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 3a1751d7f78e..2b047dd351b2 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -49,12 +49,6 @@ static int fuse_send_open(struct fuse_mount *fm, u64 nodeid, return fuse_simple_request(fm, &args); } -struct fuse_release_args { - struct fuse_args args; - struct fuse_release_in inarg; - struct inode *inode; -}; - struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release) { struct fuse_file *ff; @@ -65,9 +59,8 @@ struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release) ff->fm = fm; if (release) { - ff->release_args = kzalloc(sizeof(*ff->release_args), - GFP_KERNEL_ACCOUNT); - if (!ff->release_args) { + ff->args = kzalloc(sizeof(*ff->args), GFP_KERNEL_ACCOUNT); + if (!ff->args) { kfree(ff); return NULL; } @@ -86,7 +79,7 @@ struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release) void fuse_file_free(struct fuse_file *ff) { - kfree(ff->release_args); + kfree(ff->args); mutex_destroy(&ff->readdir.lock); kfree(ff); } @@ -109,7 +102,7 @@ static void fuse_release_end(struct fuse_mount *fm, struct fuse_args *args, static void fuse_file_put(struct fuse_file *ff, bool sync) { if (refcount_dec_and_test(&ff->count)) { - struct fuse_release_args *ra = ff->release_args; + struct fuse_release_args *ra = &ff->args->release_args; struct fuse_args *args = (ra ? &ra->args : NULL); if (ra && ra->inode) @@ -146,20 +139,21 @@ struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid, /* Default for no-open */ ff->open_flags = FOPEN_KEEP_CACHE | (isdir ? FOPEN_CACHE_DIR : 0); if (open) { - struct fuse_open_out outarg; + /* Store outarg for fuse_finish_open() */ + struct fuse_open_out *outargp = &ff->args->open_outarg; int err; - err = fuse_send_open(fm, nodeid, open_flags, opcode, &outarg); + err = fuse_send_open(fm, nodeid, open_flags, opcode, outargp); if (!err) { - ff->fh = outarg.fh; - ff->open_flags = outarg.open_flags; + ff->fh = outargp->fh; + ff->open_flags = outargp->open_flags; } else if (err != -ENOSYS) { fuse_file_free(ff); return ERR_PTR(err); } else { /* No release needed */ - kfree(ff->release_args); - ff->release_args = NULL; + kfree(ff->args); + ff->args = NULL; if (isdir) fc->no_opendir = 1; else @@ -298,7 +292,7 @@ static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff, unsigned int flags, int opcode, bool sync) { struct fuse_conn *fc = ff->fm->fc; - struct fuse_release_args *ra = ff->release_args; + struct fuse_release_args *ra = &ff->args->release_args; /* Inode is NULL on error path of fuse_create_open() */ if (likely(fi)) { @@ -316,6 +310,8 @@ static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff, if (!ra) return; + /* ff->args was used for open outarg */ + memset(ff->args, 0, sizeof(*ff->args)); ra->inarg.fh = ff->fh; ra->inarg.flags = flags; ra->args.in_numargs = 1; @@ -338,7 +334,7 @@ void fuse_file_release(struct inode *inode, struct fuse_file *ff, unsigned int open_flags, fl_owner_t id, bool isdir) { struct fuse_inode *fi = get_fuse_inode(inode); - struct fuse_release_args *ra = ff->release_args; + struct fuse_release_args *ra = &ff->args->release_args; int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE; fuse_prepare_release(fi, ff, open_flags, opcode, false); diff --git a/fs/fuse/iomode.c b/fs/fuse/iomode.c index ea47c76b9df1..2161bdf91db2 100644 --- a/fs/fuse/iomode.c +++ b/fs/fuse/iomode.c @@ -31,7 +31,7 @@ int fuse_file_cached_io_start(struct inode *inode, struct fuse_file *ff) struct fuse_inode *fi = get_fuse_inode(inode); /* There are no io modes if server does not implement open */ - if (!ff->release_args) + if (!ff->args) return 0; spin_lock(&fi->lock); @@ -103,6 +103,37 @@ void fuse_file_uncached_io_end(struct inode *inode, struct fuse_file *ff) spin_unlock(&fi->lock); } +/* + * Open flags that are allowed in combination with FOPEN_PASSTHROUGH. + * A combination of FOPEN_PASSTHROUGH and FOPEN_DIRECT_IO means that read/write + * operations go directly to the server, but mmap is done on the backing file. + * FOPEN_PASSTHROUGH mode should not co-exist with any users of the fuse inode + * page cache, so FOPEN_KEEP_CACHE is a strange and undesired combination. + */ +#define FOPEN_PASSTHROUGH_MASK \ + (FOPEN_PASSTHROUGH | FOPEN_DIRECT_IO | FOPEN_PARALLEL_DIRECT_WRITES | \ + FOPEN_NOFLUSH) + +static int fuse_file_passthrough_open(struct inode *inode, struct file *file) +{ + struct fuse_file *ff = file->private_data; + struct fuse_conn *fc = get_fuse_conn(inode); + int err; + + /* Check allowed conditions for file open in passthrough mode */ + if (!IS_ENABLED(CONFIG_FUSE_PASSTHROUGH) || !fc->passthrough || + (ff->open_flags & ~FOPEN_PASSTHROUGH_MASK)) + return -EINVAL; + + /* TODO: implement backing file open */ + return -EOPNOTSUPP; + + /* First passthrough file open denies caching inode io mode */ + err = fuse_file_uncached_io_start(inode, ff); + + return err; +} + /* Request access to submit new io to inode via open file */ int fuse_file_io_open(struct file *file, struct inode *inode) { @@ -113,7 +144,7 @@ int fuse_file_io_open(struct file *file, struct inode *inode) * io modes are not relevant with DAX and with server that does not * implement open. */ - if (FUSE_IS_DAX(inode) || !ff->release_args) + if (FUSE_IS_DAX(inode) || !ff->args) return 0; /* @@ -123,16 +154,21 @@ int fuse_file_io_open(struct file *file, struct inode *inode) ff->open_flags &= ~FOPEN_PARALLEL_DIRECT_WRITES; /* + * First passthrough file open denies caching inode io mode. * First caching file open enters caching inode io mode. * * Note that if user opens a file open with O_DIRECT, but server did * not specify FOPEN_DIRECT_IO, a later fcntl() could remove O_DIRECT, * so we put the inode in caching mode to prevent parallel dio. */ - if (ff->open_flags & FOPEN_DIRECT_IO) + if ((ff->open_flags & FOPEN_DIRECT_IO) && + !(ff->open_flags & FOPEN_PASSTHROUGH)) return 0; - err = fuse_file_cached_io_start(inode, ff); + if (ff->open_flags & FOPEN_PASSTHROUGH) + err = fuse_file_passthrough_open(inode, file); + else + err = fuse_file_cached_io_start(inode, ff); if (err) goto fail; -- 2.39.2