fuse: split out readdir.c

Directory reading code is about to grow larger, so split it out from dir.c
into a new source file.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This commit is contained in:
Miklos Szeredi 2018-09-28 16:43:23 +02:00
parent be2ff42c5d
commit d123d8e183
4 changed files with 274 additions and 258 deletions

View File

@ -5,4 +5,4 @@
obj-$(CONFIG_FUSE_FS) += fuse.o
obj-$(CONFIG_CUSE) += cuse.o
fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o acl.o
fuse-objs := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o

View File

@ -16,22 +16,6 @@
#include <linux/xattr.h>
#include <linux/posix_acl.h>
static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx)
{
struct fuse_conn *fc = get_fuse_conn(dir);
struct fuse_inode *fi = get_fuse_inode(dir);
if (!fc->do_readdirplus)
return false;
if (!fc->readdirplus_auto)
return true;
if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state))
return true;
if (ctx->pos == 0)
return true;
return false;
}
static void fuse_advise_use_readdirplus(struct inode *dir)
{
struct fuse_inode *fi = get_fuse_inode(dir);
@ -80,8 +64,7 @@ static u64 time_to_jiffies(u64 sec, u32 nsec)
* Set dentry and possibly attribute timeouts from the lookup/mk*
* replies
*/
static void fuse_change_entry_timeout(struct dentry *entry,
struct fuse_entry_out *o)
void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o)
{
fuse_dentry_settime(entry,
time_to_jiffies(o->entry_valid, o->entry_valid_nsec));
@ -92,7 +75,7 @@ static u64 attr_timeout(struct fuse_attr_out *o)
return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
}
static u64 entry_attr_timeout(struct fuse_entry_out *o)
u64 entry_attr_timeout(struct fuse_entry_out *o)
{
return time_to_jiffies(o->attr_valid, o->attr_valid_nsec);
}
@ -262,11 +245,6 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
goto out;
}
static int invalid_nodeid(u64 nodeid)
{
return !nodeid || nodeid == FUSE_ROOT_ID;
}
static int fuse_dentry_init(struct dentry *dentry)
{
dentry->d_fsdata = kzalloc(sizeof(union fuse_dentry), GFP_KERNEL);
@ -1165,239 +1143,6 @@ static int fuse_permission(struct inode *inode, int mask)
return err;
}
static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
struct dir_context *ctx)
{
while (nbytes >= FUSE_NAME_OFFSET) {
struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
size_t reclen = FUSE_DIRENT_SIZE(dirent);
if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
return -EIO;
if (reclen > nbytes)
break;
if (memchr(dirent->name, '/', dirent->namelen) != NULL)
return -EIO;
if (!dir_emit(ctx, dirent->name, dirent->namelen,
dirent->ino, dirent->type))
break;
buf += reclen;
nbytes -= reclen;
ctx->pos = dirent->off;
}
return 0;
}
static int fuse_direntplus_link(struct file *file,
struct fuse_direntplus *direntplus,
u64 attr_version)
{
struct fuse_entry_out *o = &direntplus->entry_out;
struct fuse_dirent *dirent = &direntplus->dirent;
struct dentry *parent = file->f_path.dentry;
struct qstr name = QSTR_INIT(dirent->name, dirent->namelen);
struct dentry *dentry;
struct dentry *alias;
struct inode *dir = d_inode(parent);
struct fuse_conn *fc;
struct inode *inode;
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
if (!o->nodeid) {
/*
* Unlike in the case of fuse_lookup, zero nodeid does not mean
* ENOENT. Instead, it only means the userspace filesystem did
* not want to return attributes/handle for this entry.
*
* So do nothing.
*/
return 0;
}
if (name.name[0] == '.') {
/*
* We could potentially refresh the attributes of the directory
* and its parent?
*/
if (name.len == 1)
return 0;
if (name.name[1] == '.' && name.len == 2)
return 0;
}
if (invalid_nodeid(o->nodeid))
return -EIO;
if (!fuse_valid_type(o->attr.mode))
return -EIO;
fc = get_fuse_conn(dir);
name.hash = full_name_hash(parent, name.name, name.len);
dentry = d_lookup(parent, &name);
if (!dentry) {
retry:
dentry = d_alloc_parallel(parent, &name, &wq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
}
if (!d_in_lookup(dentry)) {
struct fuse_inode *fi;
inode = d_inode(dentry);
if (!inode ||
get_node_id(inode) != o->nodeid ||
((o->attr.mode ^ inode->i_mode) & S_IFMT)) {
d_invalidate(dentry);
dput(dentry);
goto retry;
}
if (is_bad_inode(inode)) {
dput(dentry);
return -EIO;
}
fi = get_fuse_inode(inode);
spin_lock(&fc->lock);
fi->nlookup++;
spin_unlock(&fc->lock);
forget_all_cached_acls(inode);
fuse_change_attributes(inode, &o->attr,
entry_attr_timeout(o),
attr_version);
/*
* The other branch comes via fuse_iget()
* which bumps nlookup inside
*/
} else {
inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
&o->attr, entry_attr_timeout(o),
attr_version);
if (!inode)
inode = ERR_PTR(-ENOMEM);
alias = d_splice_alias(inode, dentry);
d_lookup_done(dentry);
if (alias) {
dput(dentry);
dentry = alias;
}
if (IS_ERR(dentry))
return PTR_ERR(dentry);
}
if (fc->readdirplus_auto)
set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);
fuse_change_entry_timeout(dentry, o);
dput(dentry);
return 0;
}
static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
struct dir_context *ctx, u64 attr_version)
{
struct fuse_direntplus *direntplus;
struct fuse_dirent *dirent;
size_t reclen;
int over = 0;
int ret;
while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) {
direntplus = (struct fuse_direntplus *) buf;
dirent = &direntplus->dirent;
reclen = FUSE_DIRENTPLUS_SIZE(direntplus);
if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
return -EIO;
if (reclen > nbytes)
break;
if (memchr(dirent->name, '/', dirent->namelen) != NULL)
return -EIO;
if (!over) {
/* We fill entries into dstbuf only as much as
it can hold. But we still continue iterating
over remaining entries to link them. If not,
we need to send a FORGET for each of those
which we did not link.
*/
over = !dir_emit(ctx, dirent->name, dirent->namelen,
dirent->ino, dirent->type);
if (!over)
ctx->pos = dirent->off;
}
buf += reclen;
nbytes -= reclen;
ret = fuse_direntplus_link(file, direntplus, attr_version);
if (ret)
fuse_force_forget(file, direntplus->entry_out.nodeid);
}
return 0;
}
static int fuse_readdir(struct file *file, struct dir_context *ctx)
{
int plus, err;
size_t nbytes;
struct page *page;
struct inode *inode = file_inode(file);
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req;
u64 attr_version = 0;
bool locked;
if (is_bad_inode(inode))
return -EIO;
req = fuse_get_req(fc, 1);
if (IS_ERR(req))
return PTR_ERR(req);
page = alloc_page(GFP_KERNEL);
if (!page) {
fuse_put_request(fc, req);
return -ENOMEM;
}
plus = fuse_use_readdirplus(inode, ctx);
req->out.argpages = 1;
req->num_pages = 1;
req->pages[0] = page;
req->page_descs[0].length = PAGE_SIZE;
if (plus) {
attr_version = fuse_get_attr_version(fc);
fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
FUSE_READDIRPLUS);
} else {
fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
FUSE_READDIR);
}
locked = fuse_lock_inode(inode);
fuse_request_send(fc, req);
fuse_unlock_inode(inode, locked);
nbytes = req->out.args[0].size;
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err) {
if (plus) {
err = parse_dirplusfile(page_address(page), nbytes,
file, ctx,
attr_version);
} else {
err = parse_dirfile(page_address(page), nbytes, file,
ctx);
}
}
__free_page(page);
fuse_invalidate_atime(inode);
return err;
}
static const char *fuse_get_link(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)

View File

@ -704,6 +704,11 @@ static inline u64 get_node_id(struct inode *inode)
return get_fuse_inode(inode)->nodeid;
}
static inline int invalid_nodeid(u64 nodeid)
{
return !nodeid || nodeid == FUSE_ROOT_ID;
}
/** Device operations */
extern const struct file_operations fuse_dev_operations;
@ -878,6 +883,9 @@ void fuse_invalidate_entry_cache(struct dentry *entry);
void fuse_invalidate_atime(struct inode *inode);
u64 entry_attr_timeout(struct fuse_entry_out *o);
void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
/**
* Acquire reference to fuse_conn
*/
@ -997,4 +1005,8 @@ struct posix_acl;
struct posix_acl *fuse_get_acl(struct inode *inode, int type);
int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
/* readdir.c */
int fuse_readdir(struct file *file, struct dir_context *ctx);
#endif /* _FS_FUSE_I_H */

259
fs/fuse/readdir.c Normal file
View File

@ -0,0 +1,259 @@
/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2018 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
#include "fuse_i.h"
#include <linux/posix_acl.h>
static bool fuse_use_readdirplus(struct inode *dir, struct dir_context *ctx)
{
struct fuse_conn *fc = get_fuse_conn(dir);
struct fuse_inode *fi = get_fuse_inode(dir);
if (!fc->do_readdirplus)
return false;
if (!fc->readdirplus_auto)
return true;
if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state))
return true;
if (ctx->pos == 0)
return true;
return false;
}
static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
struct dir_context *ctx)
{
while (nbytes >= FUSE_NAME_OFFSET) {
struct fuse_dirent *dirent = (struct fuse_dirent *) buf;
size_t reclen = FUSE_DIRENT_SIZE(dirent);
if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
return -EIO;
if (reclen > nbytes)
break;
if (memchr(dirent->name, '/', dirent->namelen) != NULL)
return -EIO;
if (!dir_emit(ctx, dirent->name, dirent->namelen,
dirent->ino, dirent->type))
break;
buf += reclen;
nbytes -= reclen;
ctx->pos = dirent->off;
}
return 0;
}
static int fuse_direntplus_link(struct file *file,
struct fuse_direntplus *direntplus,
u64 attr_version)
{
struct fuse_entry_out *o = &direntplus->entry_out;
struct fuse_dirent *dirent = &direntplus->dirent;
struct dentry *parent = file->f_path.dentry;
struct qstr name = QSTR_INIT(dirent->name, dirent->namelen);
struct dentry *dentry;
struct dentry *alias;
struct inode *dir = d_inode(parent);
struct fuse_conn *fc;
struct inode *inode;
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
if (!o->nodeid) {
/*
* Unlike in the case of fuse_lookup, zero nodeid does not mean
* ENOENT. Instead, it only means the userspace filesystem did
* not want to return attributes/handle for this entry.
*
* So do nothing.
*/
return 0;
}
if (name.name[0] == '.') {
/*
* We could potentially refresh the attributes of the directory
* and its parent?
*/
if (name.len == 1)
return 0;
if (name.name[1] == '.' && name.len == 2)
return 0;
}
if (invalid_nodeid(o->nodeid))
return -EIO;
if (!fuse_valid_type(o->attr.mode))
return -EIO;
fc = get_fuse_conn(dir);
name.hash = full_name_hash(parent, name.name, name.len);
dentry = d_lookup(parent, &name);
if (!dentry) {
retry:
dentry = d_alloc_parallel(parent, &name, &wq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
}
if (!d_in_lookup(dentry)) {
struct fuse_inode *fi;
inode = d_inode(dentry);
if (!inode ||
get_node_id(inode) != o->nodeid ||
((o->attr.mode ^ inode->i_mode) & S_IFMT)) {
d_invalidate(dentry);
dput(dentry);
goto retry;
}
if (is_bad_inode(inode)) {
dput(dentry);
return -EIO;
}
fi = get_fuse_inode(inode);
spin_lock(&fc->lock);
fi->nlookup++;
spin_unlock(&fc->lock);
forget_all_cached_acls(inode);
fuse_change_attributes(inode, &o->attr,
entry_attr_timeout(o),
attr_version);
/*
* The other branch comes via fuse_iget()
* which bumps nlookup inside
*/
} else {
inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
&o->attr, entry_attr_timeout(o),
attr_version);
if (!inode)
inode = ERR_PTR(-ENOMEM);
alias = d_splice_alias(inode, dentry);
d_lookup_done(dentry);
if (alias) {
dput(dentry);
dentry = alias;
}
if (IS_ERR(dentry))
return PTR_ERR(dentry);
}
if (fc->readdirplus_auto)
set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);
fuse_change_entry_timeout(dentry, o);
dput(dentry);
return 0;
}
static int parse_dirplusfile(char *buf, size_t nbytes, struct file *file,
struct dir_context *ctx, u64 attr_version)
{
struct fuse_direntplus *direntplus;
struct fuse_dirent *dirent;
size_t reclen;
int over = 0;
int ret;
while (nbytes >= FUSE_NAME_OFFSET_DIRENTPLUS) {
direntplus = (struct fuse_direntplus *) buf;
dirent = &direntplus->dirent;
reclen = FUSE_DIRENTPLUS_SIZE(direntplus);
if (!dirent->namelen || dirent->namelen > FUSE_NAME_MAX)
return -EIO;
if (reclen > nbytes)
break;
if (memchr(dirent->name, '/', dirent->namelen) != NULL)
return -EIO;
if (!over) {
/* We fill entries into dstbuf only as much as
it can hold. But we still continue iterating
over remaining entries to link them. If not,
we need to send a FORGET for each of those
which we did not link.
*/
over = !dir_emit(ctx, dirent->name, dirent->namelen,
dirent->ino, dirent->type);
if (!over)
ctx->pos = dirent->off;
}
buf += reclen;
nbytes -= reclen;
ret = fuse_direntplus_link(file, direntplus, attr_version);
if (ret)
fuse_force_forget(file, direntplus->entry_out.nodeid);
}
return 0;
}
int fuse_readdir(struct file *file, struct dir_context *ctx)
{
int plus, err;
size_t nbytes;
struct page *page;
struct inode *inode = file_inode(file);
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req;
u64 attr_version = 0;
bool locked;
if (is_bad_inode(inode))
return -EIO;
req = fuse_get_req(fc, 1);
if (IS_ERR(req))
return PTR_ERR(req);
page = alloc_page(GFP_KERNEL);
if (!page) {
fuse_put_request(fc, req);
return -ENOMEM;
}
plus = fuse_use_readdirplus(inode, ctx);
req->out.argpages = 1;
req->num_pages = 1;
req->pages[0] = page;
req->page_descs[0].length = PAGE_SIZE;
if (plus) {
attr_version = fuse_get_attr_version(fc);
fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
FUSE_READDIRPLUS);
} else {
fuse_read_fill(req, file, ctx->pos, PAGE_SIZE,
FUSE_READDIR);
}
locked = fuse_lock_inode(inode);
fuse_request_send(fc, req);
fuse_unlock_inode(inode, locked);
nbytes = req->out.args[0].size;
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err) {
if (plus) {
err = parse_dirplusfile(page_address(page), nbytes,
file, ctx, attr_version);
} else {
err = parse_dirfile(page_address(page), nbytes, file,
ctx);
}
}
__free_page(page);
fuse_invalidate_atime(inode);
return err;
}