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9p: implement i_op->atomic_open()
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Add an ->atomic_open implementation which replaces the atomic open+create
operation implemented via ->create.  No functionality is changed.

Signed-off-by: Miklos Szeredi <[email protected]>
CC: Eric Van Hensbergen <[email protected]>
Signed-off-by: Al Viro <[email protected]>
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Miklos Szeredi authored and Al Viro committed Jul 14, 2012
1 parent 2d83bde commit e43ae79
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Showing 2 changed files with 137 additions and 84 deletions.
169 changes: 102 additions & 67 deletions fs/9p/vfs_inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -712,88 +712,34 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
}

/**
* v9fs_vfs_create - VFS hook to create files
* v9fs_vfs_create - VFS hook to create a regular file
*
* open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called
* for mknod(2).
*
* @dir: directory inode that is being created
* @dentry: dentry that is being deleted
* @mode: create permissions
* @nd: path information
*
*/

static int
v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
struct nameidata *nd)
{
int err;
u32 perm;
int flags;
struct file *filp;
struct v9fs_inode *v9inode;
struct v9fs_session_info *v9ses;
struct p9_fid *fid, *inode_fid;

err = 0;
fid = NULL;
v9ses = v9fs_inode2v9ses(dir);
perm = unixmode2p9mode(v9ses, mode);
if (nd)
flags = nd->intent.open.flags;
else
flags = O_RDWR;
struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
u32 perm = unixmode2p9mode(v9ses, mode);
struct p9_fid *fid;

fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
v9fs_uflags2omode(flags,
v9fs_proto_dotu(v9ses)));
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
fid = NULL;
goto error;
}
/* P9_OEXCL? */
fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
if (IS_ERR(fid))
return PTR_ERR(fid);

v9fs_invalidate_inode_attr(dir);
/* if we are opening a file, assign the open fid to the file */
if (nd) {
v9inode = V9FS_I(dentry->d_inode);
mutex_lock(&v9inode->v_mutex);
if (v9ses->cache && !v9inode->writeback_fid &&
((flags & O_ACCMODE) != O_RDONLY)) {
/*
* clone a fid and add it to writeback_fid
* we do it during open time instead of
* page dirty time via write_begin/page_mkwrite
* because we want write after unlink usecase
* to work.
*/
inode_fid = v9fs_writeback_fid(dentry);
if (IS_ERR(inode_fid)) {
err = PTR_ERR(inode_fid);
mutex_unlock(&v9inode->v_mutex);
goto error;
}
v9inode->writeback_fid = (void *) inode_fid;
}
mutex_unlock(&v9inode->v_mutex);
filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
if (IS_ERR(filp)) {
err = PTR_ERR(filp);
goto error;
}

filp->private_data = fid;
#ifdef CONFIG_9P_FSCACHE
if (v9ses->cache)
v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
#endif
} else
p9_client_clunk(fid);
p9_client_clunk(fid);

return 0;

error:
if (fid)
p9_client_clunk(fid);

return err;
}

/**
Expand Down Expand Up @@ -910,6 +856,93 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
return ERR_PTR(result);
}

static struct file *
v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
struct opendata *od, unsigned flags, umode_t mode,
bool *created)
{
int err;
u32 perm;
struct file *filp;
struct v9fs_inode *v9inode;
struct v9fs_session_info *v9ses;
struct p9_fid *fid, *inode_fid;
struct dentry *res = NULL;

if (d_unhashed(dentry)) {
res = v9fs_vfs_lookup(dir, dentry, NULL);
if (IS_ERR(res))
return ERR_CAST(res);

if (res)
dentry = res;
}

/* Only creates */
if (!(flags & O_CREAT) || dentry->d_inode) {
finish_no_open(od, res);
return NULL;
}

err = 0;
fid = NULL;
v9ses = v9fs_inode2v9ses(dir);
perm = unixmode2p9mode(v9ses, mode);
fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
v9fs_uflags2omode(flags,
v9fs_proto_dotu(v9ses)));
if (IS_ERR(fid)) {
err = PTR_ERR(fid);
fid = NULL;
goto error;
}

v9fs_invalidate_inode_attr(dir);
v9inode = V9FS_I(dentry->d_inode);
mutex_lock(&v9inode->v_mutex);
if (v9ses->cache && !v9inode->writeback_fid &&
((flags & O_ACCMODE) != O_RDONLY)) {
/*
* clone a fid and add it to writeback_fid
* we do it during open time instead of
* page dirty time via write_begin/page_mkwrite
* because we want write after unlink usecase
* to work.
*/
inode_fid = v9fs_writeback_fid(dentry);
if (IS_ERR(inode_fid)) {
err = PTR_ERR(inode_fid);
mutex_unlock(&v9inode->v_mutex);
goto error;
}
v9inode->writeback_fid = (void *) inode_fid;
}
mutex_unlock(&v9inode->v_mutex);
filp = finish_open(od, dentry, generic_file_open);
if (IS_ERR(filp)) {
err = PTR_ERR(filp);
goto error;
}

filp->private_data = fid;
#ifdef CONFIG_9P_FSCACHE
if (v9ses->cache)
v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
#endif

*created = true;
out:
dput(res);
return filp;

error:
if (fid)
p9_client_clunk(fid);

filp = ERR_PTR(err);
goto out;
}

/**
* v9fs_vfs_unlink - VFS unlink hook to delete an inode
* @i: inode that is being unlinked
Expand Down Expand Up @@ -1488,6 +1521,7 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
static const struct inode_operations v9fs_dir_inode_operations_dotu = {
.create = v9fs_vfs_create,
.lookup = v9fs_vfs_lookup,
.atomic_open = v9fs_vfs_atomic_open,
.symlink = v9fs_vfs_symlink,
.link = v9fs_vfs_link,
.unlink = v9fs_vfs_unlink,
Expand All @@ -1502,6 +1536,7 @@ static const struct inode_operations v9fs_dir_inode_operations_dotu = {
static const struct inode_operations v9fs_dir_inode_operations = {
.create = v9fs_vfs_create,
.lookup = v9fs_vfs_lookup,
.atomic_open = v9fs_vfs_atomic_open,
.unlink = v9fs_vfs_unlink,
.mkdir = v9fs_vfs_mkdir,
.rmdir = v9fs_vfs_rmdir,
Expand Down
52 changes: 35 additions & 17 deletions fs/9p/vfs_inode_dotl.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -230,17 +230,23 @@ int v9fs_open_to_dotl_flags(int flags)
* @dir: directory inode that is being created
* @dentry: dentry that is being deleted
* @mode: create permissions
* @nd: path information
*
*/

static int
v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
struct nameidata *nd)
{
return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);
}

static struct file *
v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
struct opendata *od, unsigned flags, umode_t omode,
bool *created)
{
int err = 0;
gid_t gid;
int flags;
umode_t mode;
char *name = NULL;
struct file *filp;
Expand All @@ -251,19 +257,25 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
struct p9_fid *dfid, *ofid, *inode_fid;
struct v9fs_session_info *v9ses;
struct posix_acl *pacl = NULL, *dacl = NULL;
struct dentry *res = NULL;

v9ses = v9fs_inode2v9ses(dir);
if (nd)
flags = nd->intent.open.flags;
else {
/*
* create call without LOOKUP_OPEN is due
* to mknod of regular files. So use mknod
* operation.
*/
return v9fs_vfs_mknod_dotl(dir, dentry, omode, 0);
if (d_unhashed(dentry)) {
res = v9fs_vfs_lookup(dir, dentry, NULL);
if (IS_ERR(res))
return ERR_CAST(res);

if (res)
dentry = res;
}

/* Only creates */
if (!(flags & O_CREAT) || dentry->d_inode) {
finish_no_open(od, res);
return NULL;
}

v9ses = v9fs_inode2v9ses(dir);

name = (char *) dentry->d_name.name;
p9_debug(P9_DEBUG_VFS, "name:%s flags:0x%x mode:0x%hx\n",
name, flags, omode);
Expand All @@ -272,15 +284,15 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
if (IS_ERR(dfid)) {
err = PTR_ERR(dfid);
p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
return err;
goto err_return;
}

/* clone a fid to use for creation */
ofid = p9_client_walk(dfid, 0, NULL, 1);
if (IS_ERR(ofid)) {
err = PTR_ERR(ofid);
p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
return err;
goto err_return;
}

gid = v9fs_get_fsgid_for_create(dir);
Expand Down Expand Up @@ -345,7 +357,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
}
mutex_unlock(&v9inode->v_mutex);
/* Since we are opening a file, assign the open fid to the file */
filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
filp = finish_open(od, dentry, generic_file_open);
if (IS_ERR(filp)) {
err = PTR_ERR(filp);
goto err_clunk_old_fid;
Expand All @@ -355,7 +367,10 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
if (v9ses->cache)
v9fs_cache_inode_set_cookie(inode, filp);
#endif
return 0;
*created = true;
out:
dput(res);
return filp;

error:
if (fid)
Expand All @@ -364,7 +379,9 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, umode_t omode,
if (ofid)
p9_client_clunk(ofid);
v9fs_set_create_acl(NULL, &dacl, &pacl);
return err;
err_return:
filp = ERR_PTR(err);
goto out;
}

/**
Expand Down Expand Up @@ -982,6 +999,7 @@ int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)

const struct inode_operations v9fs_dir_inode_operations_dotl = {
.create = v9fs_vfs_create_dotl,
.atomic_open = v9fs_vfs_atomic_open_dotl,
.lookup = v9fs_vfs_lookup,
.link = v9fs_vfs_link_dotl,
.symlink = v9fs_vfs_symlink_dotl,
Expand Down

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