Commit fd72faac authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
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[PATCH] FUSE: atomic create+open



This patch adds an atomic create+open operation.  This does not yet work if
the file type changes between lookup and create+open, but solves the
permission checking problems for the separte create and open methods.
Signed-off-by: default avatarMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 31d40d74
......@@ -184,6 +184,13 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
fuse_putback_request() */
for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
up(&fc->outstanding_sem);
} else if (req->in.h.opcode == FUSE_RELEASE && req->inode == NULL) {
/* Special case for failed iget in CREATE */
u64 nodeid = req->in.h.nodeid;
__fuse_get_request(req);
fuse_reset_request(req);
fuse_send_forget(fc, req, nodeid, 1);
putback = 0;
}
if (putback)
fuse_putback_request(fc, req);
......
......@@ -13,6 +13,7 @@
#include <linux/gfp.h>
#include <linux/sched.h>
#include <linux/namei.h>
#include <linux/mount.h>
static inline unsigned long time_to_jiffies(unsigned long sec,
unsigned long nsec)
......@@ -134,6 +135,101 @@ static void fuse_invalidate_entry(struct dentry *entry)
entry->d_time = jiffies - 1;
}
static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode,
struct nameidata *nd)
{
int err;
struct inode *inode;
struct fuse_conn *fc = get_fuse_conn(dir);
struct fuse_req *req;
struct fuse_open_in inarg;
struct fuse_open_out outopen;
struct fuse_entry_out outentry;
struct fuse_inode *fi;
struct fuse_file *ff;
struct file *file;
int flags = nd->intent.open.flags - 1;
err = -ENOSYS;
if (fc->no_create)
goto out;
err = -ENAMETOOLONG;
if (entry->d_name.len > FUSE_NAME_MAX)
goto out;
err = -EINTR;
req = fuse_get_request(fc);
if (!req)
goto out;
ff = fuse_file_alloc();
if (!ff)
goto out_put_request;
flags &= ~O_NOCTTY;
memset(&inarg, 0, sizeof(inarg));
inarg.flags = flags;
inarg.mode = mode;
req->in.h.opcode = FUSE_CREATE;
req->in.h.nodeid = get_node_id(dir);
req->inode = dir;
req->in.numargs = 2;
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
req->in.args[1].size = entry->d_name.len + 1;
req->in.args[1].value = entry->d_name.name;
req->out.numargs = 2;
req->out.args[0].size = sizeof(outentry);
req->out.args[0].value = &outentry;
req->out.args[1].size = sizeof(outopen);
req->out.args[1].value = &outopen;
request_send(fc, req);
err = req->out.h.error;
if (err) {
if (err == -ENOSYS)
fc->no_create = 1;
goto out_free_ff;
}
err = -EIO;
if (!S_ISREG(outentry.attr.mode))
goto out_free_ff;
inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
&outentry.attr);
err = -ENOMEM;
if (!inode) {
flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
ff->fh = outopen.fh;
fuse_send_release(fc, ff, outentry.nodeid, NULL, flags, 0);
goto out_put_request;
}
fuse_put_request(fc, req);
entry->d_time = time_to_jiffies(outentry.entry_valid,
outentry.entry_valid_nsec);
fi = get_fuse_inode(inode);
fi->i_time = time_to_jiffies(outentry.attr_valid,
outentry.attr_valid_nsec);
d_instantiate(entry, inode);
file = lookup_instantiate_filp(nd, entry, generic_file_open);
if (IS_ERR(file)) {
ff->fh = outopen.fh;
fuse_send_release(fc, ff, outentry.nodeid, inode, flags, 0);
return PTR_ERR(file);
}
fuse_finish_open(inode, file, ff, &outopen);
return 0;
out_free_ff:
fuse_file_free(ff);
out_put_request:
fuse_put_request(fc, req);
out:
return err;
}
static int create_new_entry(struct fuse_conn *fc, struct fuse_req *req,
struct inode *dir, struct dentry *entry,
int mode)
......@@ -208,6 +304,12 @@ static int fuse_mknod(struct inode *dir, struct dentry *entry, int mode,
static int fuse_create(struct inode *dir, struct dentry *entry, int mode,
struct nameidata *nd)
{
if (nd && (nd->flags & LOOKUP_CREATE)) {
int err = fuse_create_open(dir, entry, mode, nd);
if (err != -ENOSYS)
return err;
/* Fall back on mknod */
}
return fuse_mknod(dir, entry, mode, 0);
}
......@@ -767,7 +869,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
struct nameidata *nd)
{
struct inode *inode;
int err = fuse_lookup_iget(dir, entry, &inode);
int err;
err = fuse_lookup_iget(dir, entry, &inode);
if (err)
return ERR_PTR(err);
if (inode && S_ISDIR(inode->i_mode)) {
......
......@@ -14,11 +14,69 @@
static struct file_operations fuse_direct_io_file_operations;
int fuse_open_common(struct inode *inode, struct file *file, int isdir)
static int fuse_send_open(struct inode *inode, struct file *file, int isdir,
struct fuse_open_out *outargp)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req;
struct fuse_open_in inarg;
struct fuse_req *req;
int err;
req = fuse_get_request(fc);
if (!req)
return -EINTR;
memset(&inarg, 0, sizeof(inarg));
inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->in.numargs = 1;
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
req->out.numargs = 1;
req->out.args[0].size = sizeof(*outargp);
req->out.args[0].value = outargp;
request_send(fc, req);
err = req->out.h.error;
fuse_put_request(fc, req);
return err;
}
struct fuse_file *fuse_file_alloc(void)
{
struct fuse_file *ff;
ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
if (ff) {
ff->release_req = fuse_request_alloc();
if (!ff->release_req) {
kfree(ff);
ff = NULL;
}
}
return ff;
}
void fuse_file_free(struct fuse_file *ff)
{
fuse_request_free(ff->release_req);
kfree(ff);
}
void fuse_finish_open(struct inode *inode, struct file *file,
struct fuse_file *ff, struct fuse_open_out *outarg)
{
if (outarg->open_flags & FOPEN_DIRECT_IO)
file->f_op = &fuse_direct_io_file_operations;
if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
invalidate_inode_pages(inode->i_mapping);
ff->fh = outarg->fh;
file->private_data = ff;
}
int fuse_open_common(struct inode *inode, struct file *file, int isdir)
{
struct fuse_open_out outarg;
struct fuse_file *ff;
int err;
......@@ -34,73 +92,53 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir)
/* If opening the root node, no lookup has been performed on
it, so the attributes must be refreshed */
if (get_node_id(inode) == FUSE_ROOT_ID) {
int err = fuse_do_getattr(inode);
err = fuse_do_getattr(inode);
if (err)
return err;
}
req = fuse_get_request(fc);
if (!req)
return -EINTR;
err = -ENOMEM;
ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
ff = fuse_file_alloc();
if (!ff)
goto out_put_request;
return -ENOMEM;
ff->release_req = fuse_request_alloc();
if (!ff->release_req) {
kfree(ff);
goto out_put_request;
}
memset(&inarg, 0, sizeof(inarg));
inarg.flags = file->f_flags & ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
req->in.h.opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
req->in.h.nodeid = get_node_id(inode);
req->inode = inode;
req->in.numargs = 1;
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
req->out.numargs = 1;
req->out.args[0].size = sizeof(outarg);
req->out.args[0].value = &outarg;
request_send(fc, req);
err = req->out.h.error;
if (err) {
fuse_request_free(ff->release_req);
kfree(ff);
} else {
if (!isdir && (outarg.open_flags & FOPEN_DIRECT_IO))
file->f_op = &fuse_direct_io_file_operations;
if (!(outarg.open_flags & FOPEN_KEEP_CACHE))
invalidate_inode_pages(inode->i_mapping);
ff->fh = outarg.fh;
file->private_data = ff;
err = fuse_send_open(inode, file, isdir, &outarg);
if (err)
fuse_file_free(ff);
else {
if (isdir)
outarg.open_flags &= ~FOPEN_DIRECT_IO;
fuse_finish_open(inode, file, ff, &outarg);
}
out_put_request:
fuse_put_request(fc, req);
return err;
}
int fuse_release_common(struct inode *inode, struct file *file, int isdir)
void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
u64 nodeid, struct inode *inode, int flags, int isdir)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_file *ff = file->private_data;
struct fuse_req *req = ff->release_req;
struct fuse_req * req = ff->release_req;
struct fuse_release_in *inarg = &req->misc.release_in;
inarg->fh = ff->fh;
inarg->flags = file->f_flags & ~O_EXCL;
inarg->flags = flags;
req->in.h.opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
req->in.h.nodeid = get_node_id(inode);
req->in.h.nodeid = nodeid;
req->inode = inode;
req->in.numargs = 1;
req->in.args[0].size = sizeof(struct fuse_release_in);
req->in.args[0].value = inarg;
request_send_background(fc, req);
kfree(ff);
}
int fuse_release_common(struct inode *inode, struct file *file, int isdir)
{
struct fuse_file *ff = file->private_data;
if (ff) {
struct fuse_conn *fc = get_fuse_conn(inode);
u64 nodeid = get_node_id(inode);
fuse_send_release(fc, ff, nodeid, inode, file->f_flags, isdir);
}
/* Return value is ignored by VFS */
return 0;
......
......@@ -269,6 +269,9 @@ struct fuse_conn {
/** Is access not implemented by fs? */
unsigned no_access : 1;
/** Is create not implemented by fs? */
unsigned no_create : 1;
/** Backing dev info */
struct backing_dev_info bdi;
};
......@@ -340,6 +343,17 @@ size_t fuse_send_read_common(struct fuse_req *req, struct file *file,
*/
int fuse_open_common(struct inode *inode, struct file *file, int isdir);
struct fuse_file *fuse_file_alloc(void);
void fuse_file_free(struct fuse_file *ff);
void fuse_finish_open(struct inode *inode, struct file *file,
struct fuse_file *ff, struct fuse_open_out *outarg);
/**
* Send a RELEASE request
*/
void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
u64 nodeid, struct inode *inode, int flags, int isdir);
/**
* Send RELEASE or RELEASEDIR request
*/
......
......@@ -100,7 +100,8 @@ enum fuse_opcode {
FUSE_READDIR = 28,
FUSE_RELEASEDIR = 29,
FUSE_FSYNCDIR = 30,
FUSE_ACCESS = 34
FUSE_ACCESS = 34,
FUSE_CREATE = 35
};
/* Conservative buffer size for the client */
......@@ -158,7 +159,7 @@ struct fuse_setattr_in {
struct fuse_open_in {
__u32 flags;
__u32 padding;
__u32 mode;
};
struct fuse_open_out {
......
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