diff options
| -rw-r--r-- | fs/fuse/Makefile | 1 | ||||
| -rw-r--r-- | fs/fuse/file.c | 15 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 17 | ||||
| -rw-r--r-- | fs/fuse/iomode.c | 158 |
4 files changed, 189 insertions, 2 deletions
diff --git a/fs/fuse/Makefile b/fs/fuse/Makefile index 0c48b35c058d..b734cc2a5e65 100644 --- a/fs/fuse/Makefile +++ b/fs/fuse/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_CUSE) += cuse.o obj-$(CONFIG_VIRTIO_FS) += virtiofs.o fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o ioctl.o +fuse-y += iomode.o fuse-$(CONFIG_FUSE_DAX) += dax.o virtiofs-y := virtio_fs.o diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 27f50b4bd7f3..9af356fbc578 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -113,6 +113,9 @@ static void fuse_file_put(struct fuse_file *ff, bool sync) struct fuse_release_args *ra = ff->release_args; struct fuse_args *args = (ra ? &ra->args : NULL); + if (ra && ra->inode) + fuse_file_io_release(ff, ra->inode); + if (!args) { /* Do nothing when server does not implement 'open' */ } else if (sync) { @@ -204,6 +207,11 @@ int fuse_finish_open(struct inode *inode, struct file *file) { struct fuse_file *ff = file->private_data; struct fuse_conn *fc = get_fuse_conn(inode); + int err; + + err = fuse_file_io_open(file, inode); + if (err) + return err; if (ff->open_flags & FOPEN_STREAM) stream_open(inode, file); @@ -2509,6 +2517,7 @@ static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) { struct fuse_file *ff = file->private_data; struct fuse_conn *fc = ff->fm->fc; + int rc; /* DAX mmap is superior to direct_io mmap */ if (FUSE_IS_DAX(file_inode(file))) @@ -2528,6 +2537,11 @@ static int fuse_file_mmap(struct file *file, struct vm_area_struct *vma) /* MAP_PRIVATE */ return generic_file_mmap(file, vma); } + + /* First mmap of direct_io file enters caching inode io mode. */ + rc = fuse_file_cached_io_start(file_inode(file), ff); + if (rc) + return rc; } if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE)) @@ -3296,6 +3310,7 @@ void fuse_init_file_inode(struct inode *inode, unsigned int flags) INIT_LIST_HEAD(&fi->write_files); INIT_LIST_HEAD(&fi->queued_writes); fi->writectr = 0; + fi->iocachectr = 0; init_waitqueue_head(&fi->page_waitq); fi->writepages = RB_ROOT; diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 8cabce8e4282..57ee9afefee2 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -111,7 +111,7 @@ struct fuse_inode { u64 attr_version; union { - /* Write related fields (regular file only) */ + /* read/write io cache (regular file only) */ struct { /* Files usable in writepage. Protected by fi->lock */ struct list_head write_files; @@ -123,6 +123,9 @@ struct fuse_inode { * (FUSE_NOWRITE) means more writes are blocked */ int writectr; + /** Number of files/maps using page cache */ + int iocachectr; + /* Waitq for writepage completion */ wait_queue_head_t page_waitq; @@ -187,6 +190,8 @@ enum { FUSE_I_BAD, /* Has btime */ FUSE_I_BTIME, + /* Wants or already has page cache IO */ + FUSE_I_CACHE_IO_MODE, }; struct fuse_conn; @@ -244,6 +249,9 @@ struct fuse_file { /** Wait queue head for poll */ wait_queue_head_t poll_wait; + /** Does file hold a fi->iocachectr refcount? */ + enum { IOM_NONE, IOM_CACHED, IOM_UNCACHED } iomode; + /** Has flock been performed on this file? */ bool flock:1; }; @@ -1343,8 +1351,13 @@ int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa); int fuse_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, struct fileattr *fa); -/* file.c */ +/* iomode.c */ +int fuse_file_cached_io_start(struct inode *inode, struct fuse_file *ff); +int fuse_file_io_open(struct file *file, struct inode *inode); +void fuse_file_io_release(struct fuse_file *ff, struct inode *inode); + +/* file.c */ struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid, unsigned int open_flags, bool isdir); void fuse_file_release(struct inode *inode, struct fuse_file *ff, diff --git a/fs/fuse/iomode.c b/fs/fuse/iomode.c new file mode 100644 index 000000000000..a1a836b2aacc --- /dev/null +++ b/fs/fuse/iomode.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * FUSE inode io modes. + * + * Copyright (c) 2024 CTERA Networks. + */ + +#include "fuse_i.h" + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/file.h> +#include <linux/fs.h> + +/* + * Start cached io mode, where parallel dio writes are not allowed. + */ +int fuse_file_cached_io_start(struct inode *inode, struct fuse_file *ff) +{ + struct fuse_inode *fi = get_fuse_inode(inode); + int err = 0; + + /* There are no io modes if server does not implement open */ + if (!ff->release_args) + return 0; + + spin_lock(&fi->lock); + if (fi->iocachectr < 0) { + err = -ETXTBSY; + goto unlock; + } + WARN_ON(ff->iomode == IOM_UNCACHED); + if (ff->iomode == IOM_NONE) { + ff->iomode = IOM_CACHED; + if (fi->iocachectr == 0) + set_bit(FUSE_I_CACHE_IO_MODE, &fi->state); + fi->iocachectr++; + } +unlock: + spin_unlock(&fi->lock); + return err; +} + +static void fuse_file_cached_io_end(struct inode *inode, struct fuse_file *ff) +{ + struct fuse_inode *fi = get_fuse_inode(inode); + + spin_lock(&fi->lock); + WARN_ON(fi->iocachectr <= 0); + WARN_ON(ff->iomode != IOM_CACHED); + ff->iomode = IOM_NONE; + fi->iocachectr--; + if (fi->iocachectr == 0) + clear_bit(FUSE_I_CACHE_IO_MODE, &fi->state); + spin_unlock(&fi->lock); +} + +/* Start strictly uncached io mode where cache access is not allowed */ +static int fuse_file_uncached_io_start(struct inode *inode, struct fuse_file *ff) +{ + struct fuse_inode *fi = get_fuse_inode(inode); + int err = 0; + + spin_lock(&fi->lock); + if (fi->iocachectr > 0) { + err = -ETXTBSY; + goto unlock; + } + WARN_ON(ff->iomode != IOM_NONE); + fi->iocachectr--; + ff->iomode = IOM_UNCACHED; +unlock: + spin_unlock(&fi->lock); + return err; +} + +static void fuse_file_uncached_io_end(struct inode *inode, struct fuse_file *ff) +{ + struct fuse_inode *fi = get_fuse_inode(inode); + + spin_lock(&fi->lock); + WARN_ON(fi->iocachectr >= 0); + WARN_ON(ff->iomode != IOM_UNCACHED); + ff->iomode = IOM_NONE; + fi->iocachectr++; + spin_unlock(&fi->lock); +} + +/* Request access to submit new io to inode via open file */ +int fuse_file_io_open(struct file *file, struct inode *inode) +{ + struct fuse_file *ff = file->private_data; + int err; + + /* + * io modes are not relevant with DAX and with server that does not + * implement open. + */ + if (FUSE_IS_DAX(inode) || !ff->release_args) + return 0; + + /* + * FOPEN_PARALLEL_DIRECT_WRITES requires FOPEN_DIRECT_IO. + */ + if (!(ff->open_flags & FOPEN_DIRECT_IO)) + ff->open_flags &= ~FOPEN_PARALLEL_DIRECT_WRITES; + + /* + * First parallel dio 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_PARALLEL_DIRECT_WRITES) + err = fuse_file_uncached_io_start(inode, ff); + else + return 0; + } else { + err = fuse_file_cached_io_start(inode, ff); + } + if (err) + goto fail; + + return 0; + +fail: + pr_debug("failed to open file in requested io mode (open_flags=0x%x, err=%i).\n", + ff->open_flags, err); + /* + * The file open mode determines the inode io mode. + * Using incorrect open mode is a server mistake, which results in + * user visible failure of open() with EIO error. + */ + return -EIO; +} + +/* No more pending io and no new io possible to inode via open/mmapped file */ +void fuse_file_io_release(struct fuse_file *ff, struct inode *inode) +{ + /* + * Last parallel dio close allows caching inode io mode. + * Last caching file close exits caching inode io mode. + */ + switch (ff->iomode) { + case IOM_NONE: + /* Nothing to do */ + break; + case IOM_UNCACHED: + fuse_file_uncached_io_end(inode, ff); + break; + case IOM_CACHED: + fuse_file_cached_io_end(inode, ff); + break; + } +} |