[PATCH] fuse: more flexible caching
Make data caching behavior selectable on a per-open basis instead of per-mount. Compatibility for the old mount options 'kernel_cache' and 'direct_io' is retained in the userspace library (version 2.4.0-pre1 or later). Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>wifi-calibration
Miklos Szeredi
Linus Torvalds
parent
04730fef1f
commit
45323fb764
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@ -80,32 +80,6 @@ Mount options
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allowed to root, but this restriction can be removed with a
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(userspace) configuration option.
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'kernel_cache'
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This option disables flushing the cache of the file contents on
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every open(). This should only be enabled on filesystems, where the
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file data is never changed externally (not through the mounted FUSE
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filesystem). Thus it is not suitable for network filesystems and
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other "intermediate" filesystems.
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NOTE: if this option is not specified (and neither 'direct_io') data
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is still cached after the open(), so a read() system call will not
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always initiate a read operation.
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'direct_io'
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This option disables the use of page cache (file content cache) in
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the kernel for this filesystem. This has several affects:
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- Each read() or write() system call will initiate one or more
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read or write operations, data will not be cached in the
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kernel.
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- The return value of the read() and write() system calls will
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correspond to the return values of the read and write
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operations. This is useful for example if the file size is not
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known in advance (before reading it).
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'max_read=N'
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With this option the maximum size of read operations can be set.
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@ -12,6 +12,8 @@
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#include <linux/slab.h>
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#include <linux/kernel.h>
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static struct file_operations fuse_direct_io_file_operations;
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int fuse_open_common(struct inode *inode, struct file *file, int isdir)
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{
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struct fuse_conn *fc = get_fuse_conn(inode);
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@ -70,12 +72,14 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir)
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else
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request_send(fc, req);
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err = req->out.h.error;
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if (!err && !(fc->flags & FUSE_KERNEL_CACHE))
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invalidate_inode_pages(inode->i_mapping);
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if (err) {
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fuse_request_free(ff->release_req);
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kfree(ff);
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} else {
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if (!isdir && (outarg.open_flags & FOPEN_DIRECT_IO))
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file->f_op = &fuse_direct_io_file_operations;
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if (!(outarg.open_flags & FOPEN_KEEP_CACHE))
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invalidate_inode_pages(inode->i_mapping);
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ff->fh = outarg.fh;
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file->private_data = ff;
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}
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@ -544,12 +548,6 @@ static struct address_space_operations fuse_file_aops = {
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void fuse_init_file_inode(struct inode *inode)
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{
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struct fuse_conn *fc = get_fuse_conn(inode);
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if (fc->flags & FUSE_DIRECT_IO)
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inode->i_fop = &fuse_direct_io_file_operations;
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else {
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inode->i_fop = &fuse_file_operations;
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inode->i_data.a_ops = &fuse_file_aops;
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}
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inode->i_fop = &fuse_file_operations;
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inode->i_data.a_ops = &fuse_file_aops;
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}
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@ -30,12 +30,6 @@
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doing the mount will be allowed to access the filesystem */
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#define FUSE_ALLOW_OTHER (1 << 1)
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/** If the FUSE_KERNEL_CACHE flag is given, then cached data will not
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be flushed on open */
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#define FUSE_KERNEL_CACHE (1 << 2)
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/** Bypass the page cache for read and write operations */
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#define FUSE_DIRECT_IO (1 << 3)
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/** FUSE inode */
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struct fuse_inode {
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@ -257,8 +257,6 @@ enum {
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OPT_GROUP_ID,
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OPT_DEFAULT_PERMISSIONS,
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OPT_ALLOW_OTHER,
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OPT_KERNEL_CACHE,
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OPT_DIRECT_IO,
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OPT_MAX_READ,
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OPT_ERR
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};
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@ -270,8 +268,6 @@ static match_table_t tokens = {
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{OPT_GROUP_ID, "group_id=%u"},
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{OPT_DEFAULT_PERMISSIONS, "default_permissions"},
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{OPT_ALLOW_OTHER, "allow_other"},
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{OPT_KERNEL_CACHE, "kernel_cache"},
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{OPT_DIRECT_IO, "direct_io"},
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{OPT_MAX_READ, "max_read=%u"},
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{OPT_ERR, NULL}
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};
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@ -327,14 +323,6 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
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d->flags |= FUSE_ALLOW_OTHER;
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break;
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case OPT_KERNEL_CACHE:
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d->flags |= FUSE_KERNEL_CACHE;
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break;
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case OPT_DIRECT_IO:
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d->flags |= FUSE_DIRECT_IO;
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break;
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case OPT_MAX_READ:
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if (match_int(&args[0], &value))
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return 0;
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@ -363,10 +351,6 @@ static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
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seq_puts(m, ",default_permissions");
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if (fc->flags & FUSE_ALLOW_OTHER)
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seq_puts(m, ",allow_other");
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if (fc->flags & FUSE_KERNEL_CACHE)
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seq_puts(m, ",kernel_cache");
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if (fc->flags & FUSE_DIRECT_IO)
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seq_puts(m, ",direct_io");
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if (fc->max_read != ~0)
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seq_printf(m, ",max_read=%u", fc->max_read);
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return 0;
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@ -14,7 +14,7 @@
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#define FUSE_KERNEL_VERSION 7
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/** Minor version number of this interface */
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#define FUSE_KERNEL_MINOR_VERSION 1
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#define FUSE_KERNEL_MINOR_VERSION 2
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/** The node ID of the root inode */
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#define FUSE_ROOT_ID 1
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@ -63,6 +63,15 @@ struct fuse_kstatfs {
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#define FATTR_MTIME (1 << 5)
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#define FATTR_CTIME (1 << 6)
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/**
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* Flags returned by the OPEN request
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*
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* FOPEN_DIRECT_IO: bypass page cache for this open file
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* FOPEN_KEEP_CACHE: don't invalidate the data cache on open
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*/
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#define FOPEN_DIRECT_IO (1 << 0)
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#define FOPEN_KEEP_CACHE (1 << 1)
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enum fuse_opcode {
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FUSE_LOOKUP = 1,
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FUSE_FORGET = 2, /* no reply */
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