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zfs/module/spl/spl-vnode.c

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/*****************************************************************************\
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://zfsonlinux.org/>.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
*****************************************************************************
* Solaris Porting Layer (SPL) Vnode Implementation.
\*****************************************************************************/
#include <sys/cred.h>
#include <sys/vnode.h>
#include <sys/kmem_cache.h>
#include <linux/falloc.h>
#include <linux/file_compat.h>
vnode_t *rootdir = (vnode_t *)0xabcd1234;
EXPORT_SYMBOL(rootdir);
static spl_kmem_cache_t *vn_cache;
static spl_kmem_cache_t *vn_file_cache;
static DEFINE_SPINLOCK(vn_file_lock);
static LIST_HEAD(vn_file_list);
vtype_t
vn_mode_to_vtype(mode_t mode)
{
if (S_ISREG(mode))
return VREG;
if (S_ISDIR(mode))
return VDIR;
if (S_ISCHR(mode))
return VCHR;
if (S_ISBLK(mode))
return VBLK;
if (S_ISFIFO(mode))
return VFIFO;
if (S_ISLNK(mode))
return VLNK;
if (S_ISSOCK(mode))
return VSOCK;
if (S_ISCHR(mode))
return VCHR;
return VNON;
} /* vn_mode_to_vtype() */
EXPORT_SYMBOL(vn_mode_to_vtype);
mode_t
vn_vtype_to_mode(vtype_t vtype)
{
if (vtype == VREG)
return S_IFREG;
if (vtype == VDIR)
return S_IFDIR;
if (vtype == VCHR)
return S_IFCHR;
if (vtype == VBLK)
return S_IFBLK;
if (vtype == VFIFO)
return S_IFIFO;
if (vtype == VLNK)
return S_IFLNK;
if (vtype == VSOCK)
return S_IFSOCK;
return VNON;
} /* vn_vtype_to_mode() */
EXPORT_SYMBOL(vn_vtype_to_mode);
vnode_t *
vn_alloc(int flag)
{
vnode_t *vp;
vp = kmem_cache_alloc(vn_cache, flag);
if (vp != NULL) {
vp->v_file = NULL;
vp->v_type = 0;
}
return (vp);
} /* vn_alloc() */
EXPORT_SYMBOL(vn_alloc);
void
vn_free(vnode_t *vp)
{
kmem_cache_free(vn_cache, vp);
} /* vn_free() */
EXPORT_SYMBOL(vn_free);
int
vn_open(const char *path, uio_seg_t seg, int flags, int mode,
vnode_t **vpp, int x1, void *x2)
{
struct file *fp;
struct kstat stat;
int rc, saved_umask = 0;
gfp_t saved_gfp;
vnode_t *vp;
ASSERT(flags & (FWRITE | FREAD));
ASSERT(seg == UIO_SYSSPACE);
ASSERT(vpp);
*vpp = NULL;
if (!(flags & FCREAT) && (flags & FWRITE))
flags |= FEXCL;
/* Note for filp_open() the two low bits must be remapped to mean:
* 01 - read-only -> 00 read-only
* 10 - write-only -> 01 write-only
* 11 - read-write -> 10 read-write
*/
flags--;
if (flags & FCREAT)
saved_umask = xchg(&current->fs->umask, 0);
fp = filp_open(path, flags, mode);
if (flags & FCREAT)
(void)xchg(&current->fs->umask, saved_umask);
if (IS_ERR(fp))
return (-PTR_ERR(fp));
#ifdef HAVE_2ARGS_VFS_GETATTR
rc = vfs_getattr(&fp->f_path, &stat);
#else
rc = vfs_getattr(fp->f_path.mnt, fp->f_dentry, &stat);
#endif
if (rc) {
filp_close(fp, 0);
return (-rc);
}
vp = vn_alloc(KM_SLEEP);
if (!vp) {
filp_close(fp, 0);
return (ENOMEM);
}
saved_gfp = mapping_gfp_mask(fp->f_mapping);
mapping_set_gfp_mask(fp->f_mapping, saved_gfp & ~(__GFP_IO|__GFP_FS));
mutex_enter(&vp->v_lock);
vp->v_type = vn_mode_to_vtype(stat.mode);
vp->v_file = fp;
vp->v_gfp_mask = saved_gfp;
*vpp = vp;
mutex_exit(&vp->v_lock);
return (0);
} /* vn_open() */
EXPORT_SYMBOL(vn_open);
int
vn_openat(const char *path, uio_seg_t seg, int flags, int mode,
vnode_t **vpp, int x1, void *x2, vnode_t *vp, int fd)
{
char *realpath;
int len, rc;
ASSERT(vp == rootdir);
len = strlen(path) + 2;
realpath = kmalloc(len, GFP_KERNEL);
if (!realpath)
return (ENOMEM);
(void)snprintf(realpath, len, "/%s", path);
rc = vn_open(realpath, seg, flags, mode, vpp, x1, x2);
kfree(realpath);
return (rc);
} /* vn_openat() */
EXPORT_SYMBOL(vn_openat);
int
vn_rdwr(uio_rw_t uio, vnode_t *vp, void *addr, ssize_t len, offset_t off,
uio_seg_t seg, int ioflag, rlim64_t x2, void *x3, ssize_t *residp)
{
loff_t offset;
mm_segment_t saved_fs;
struct file *fp;
int rc;
ASSERT(uio == UIO_WRITE || uio == UIO_READ);
ASSERT(vp);
ASSERT(vp->v_file);
ASSERT(seg == UIO_SYSSPACE);
ASSERT((ioflag & ~FAPPEND) == 0);
ASSERT(x2 == RLIM64_INFINITY);
fp = vp->v_file;
offset = off;
if (ioflag & FAPPEND)
offset = fp->f_pos;
/* Writable user data segment must be briefly increased for this
* process so we can use the user space read call paths to write
* in to memory allocated by the kernel. */
saved_fs = get_fs();
set_fs(get_ds());
if (uio & UIO_WRITE)
rc = vfs_write(fp, addr, len, &offset);
else
rc = vfs_read(fp, addr, len, &offset);
set_fs(saved_fs);
fp->f_pos = offset;
if (rc < 0)
return (-rc);
if (residp) {
*residp = len - rc;
} else {
if (rc != len)
return (EIO);
}
return (0);
} /* vn_rdwr() */
EXPORT_SYMBOL(vn_rdwr);
int
vn_close(vnode_t *vp, int flags, int x1, int x2, void *x3, void *x4)
{
int rc;
ASSERT(vp);
ASSERT(vp->v_file);
mapping_set_gfp_mask(vp->v_file->f_mapping, vp->v_gfp_mask);
rc = filp_close(vp->v_file, 0);
vn_free(vp);
return (-rc);
} /* vn_close() */
EXPORT_SYMBOL(vn_close);
/* vn_seek() does not actually seek it only performs bounds checking on the
* proposed seek. We perform minimal checking and allow vn_rdwr() to catch
* anything more serious. */
int
vn_seek(vnode_t *vp, offset_t ooff, offset_t *noffp, void *ct)
{
return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0);
}
EXPORT_SYMBOL(vn_seek);
/*
* spl_basename() takes a NULL-terminated string s as input containing a path.
* It returns a char pointer to a string and a length that describe the
* basename of the path. If the basename is not "." or "/", it will be an index
* into the string. While the string should be NULL terminated, the section
* referring to the basename is not. spl_basename is dual-licensed GPLv2+ and
* CC0. Anyone wishing to reuse it in another codebase may pick either license.
*/
static void
spl_basename(const char *s, const char **str, int *len)
{
size_t i, end;
ASSERT(str);
ASSERT(len);
if (!s || !*s) {
*str = ".";
*len = 1;
return;
}
i = strlen(s) - 1;
while (i && s[i--] == '/');
if (i == 0) {
*str = "/";
*len = 1;
return;
}
end = i;
for (end = i; i; i--) {
if (s[i] == '/') {
*str = &s[i+1];
*len = end - i + 1;
return;
}
}
*str = s;
*len = end + 1;
}
static struct dentry *
spl_kern_path_locked(const char *name, struct path *path)
{
struct path parent;
struct dentry *dentry;
const char *basename;
int len;
int rc;
ASSERT(name);
ASSERT(path);
spl_basename(name, &basename, &len);
/* We do not accept "." or ".." */
if (len <= 2 && basename[0] == '.')
if (len == 1 || basename[1] == '.')
return (ERR_PTR(-EACCES));
rc = kern_path(name, LOOKUP_PARENT, &parent);
if (rc)
return (ERR_PTR(rc));
spl_inode_lock(parent.dentry->d_inode);
dentry = lookup_one_len(basename, parent.dentry, len);
if (IS_ERR(dentry)) {
spl_inode_unlock(parent.dentry->d_inode);
path_put(&parent);
} else {
*path = parent;
}
return (dentry);
}
/* Based on do_unlinkat() from linux/fs/namei.c */
int
vn_remove(const char *path, uio_seg_t seg, int flags)
{
struct dentry *dentry;
struct path parent;
struct inode *inode = NULL;
int rc = 0;
ASSERT(seg == UIO_SYSSPACE);
ASSERT(flags == RMFILE);
dentry = spl_kern_path_locked(path, &parent);
rc = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
if (parent.dentry->d_name.name[parent.dentry->d_name.len]) {
rc = 0;
goto slashes;
}
inode = dentry->d_inode;
if (inode) {
atomic_inc(&inode->i_count);
} else {
rc = 0;
goto slashes;
}
#ifdef HAVE_2ARGS_VFS_UNLINK
rc = vfs_unlink(parent.dentry->d_inode, dentry);
#else
rc = vfs_unlink(parent.dentry->d_inode, dentry, NULL);
#endif /* HAVE_2ARGS_VFS_UNLINK */
exit1:
dput(dentry);
} else {
return (-rc);
}
spl_inode_unlock(parent.dentry->d_inode);
if (inode)
iput(inode); /* truncate the inode here */
path_put(&parent);
return (-rc);
slashes:
rc = !dentry->d_inode ? -ENOENT :
S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR;
goto exit1;
} /* vn_remove() */
EXPORT_SYMBOL(vn_remove);
/* Based on do_rename() from linux/fs/namei.c */
int
vn_rename(const char *oldname, const char *newname, int x1)
{
struct dentry *old_dir, *new_dir;
struct dentry *old_dentry, *new_dentry;
struct dentry *trap;
struct path old_parent, new_parent;
int rc = 0;
old_dentry = spl_kern_path_locked(oldname, &old_parent);
if (IS_ERR(old_dentry)) {
rc = PTR_ERR(old_dentry);
goto exit;
}
spl_inode_unlock(old_parent.dentry->d_inode);
new_dentry = spl_kern_path_locked(newname, &new_parent);
if (IS_ERR(new_dentry)) {
rc = PTR_ERR(new_dentry);
goto exit2;
}
spl_inode_unlock(new_parent.dentry->d_inode);
rc = -EXDEV;
if (old_parent.mnt != new_parent.mnt)
goto exit3;
old_dir = old_parent.dentry;
new_dir = new_parent.dentry;
trap = lock_rename(new_dir, old_dir);
/* source should not be ancestor of target */
rc = -EINVAL;
if (old_dentry == trap)
goto exit4;
/* target should not be an ancestor of source */
rc = -ENOTEMPTY;
if (new_dentry == trap)
goto exit4;
/* source must exist */
rc = -ENOENT;
if (!old_dentry->d_inode)
goto exit4;
/* unless the source is a directory trailing slashes give -ENOTDIR */
if (!S_ISDIR(old_dentry->d_inode->i_mode)) {
rc = -ENOTDIR;
if (old_dentry->d_name.name[old_dentry->d_name.len])
goto exit4;
if (new_dentry->d_name.name[new_dentry->d_name.len])
goto exit4;
}
#if defined(HAVE_4ARGS_VFS_RENAME)
rc = vfs_rename(old_dir->d_inode, old_dentry,
new_dir->d_inode, new_dentry);
#elif defined(HAVE_5ARGS_VFS_RENAME)
rc = vfs_rename(old_dir->d_inode, old_dentry,
new_dir->d_inode, new_dentry, NULL);
#else
rc = vfs_rename(old_dir->d_inode, old_dentry,
new_dir->d_inode, new_dentry, NULL, 0);
#endif
exit4:
unlock_rename(new_dir, old_dir);
exit3:
dput(new_dentry);
path_put(&new_parent);
exit2:
dput(old_dentry);
path_put(&old_parent);
exit:
return (-rc);
}
EXPORT_SYMBOL(vn_rename);
int
vn_getattr(vnode_t *vp, vattr_t *vap, int flags, void *x3, void *x4)
{
struct file *fp;
struct kstat stat;
int rc;
ASSERT(vp);
ASSERT(vp->v_file);
ASSERT(vap);
fp = vp->v_file;
#ifdef HAVE_2ARGS_VFS_GETATTR
rc = vfs_getattr(&fp->f_path, &stat);
#else
rc = vfs_getattr(fp->f_path.mnt, fp->f_dentry, &stat);
#endif
if (rc)
return (-rc);
vap->va_type = vn_mode_to_vtype(stat.mode);
vap->va_mode = stat.mode;
vap->va_uid = KUID_TO_SUID(stat.uid);
vap->va_gid = KGID_TO_SGID(stat.gid);
vap->va_fsid = 0;
vap->va_nodeid = stat.ino;
vap->va_nlink = stat.nlink;
vap->va_size = stat.size;
vap->va_blksize = stat.blksize;
vap->va_atime = stat.atime;
vap->va_mtime = stat.mtime;
vap->va_ctime = stat.ctime;
vap->va_rdev = stat.rdev;
vap->va_nblocks = stat.blocks;
return (0);
}
EXPORT_SYMBOL(vn_getattr);
int vn_fsync(vnode_t *vp, int flags, void *x3, void *x4)
{
int datasync = 0;
ASSERT(vp);
ASSERT(vp->v_file);
if (flags & FDSYNC)
datasync = 1;
return (-spl_filp_fsync(vp->v_file, datasync));
} /* vn_fsync() */
EXPORT_SYMBOL(vn_fsync);
int vn_space(vnode_t *vp, int cmd, struct flock *bfp, int flag,
offset_t offset, void *x6, void *x7)
{
int error = EOPNOTSUPP;
if (cmd != F_FREESP || bfp->l_whence != 0)
return (EOPNOTSUPP);
ASSERT(vp);
ASSERT(vp->v_file);
ASSERT(bfp->l_start >= 0 && bfp->l_len > 0);
#ifdef FALLOC_FL_PUNCH_HOLE
/*
* When supported by the underlying file system preferentially
* use the fallocate() callback to preallocate the space.
*/
error = -spl_filp_fallocate(vp->v_file,
FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE,
bfp->l_start, bfp->l_len);
if (error == 0)
return (0);
#endif
#ifdef HAVE_INODE_TRUNCATE_RANGE
if (vp->v_file->f_dentry && vp->v_file->f_dentry->d_inode &&
vp->v_file->f_dentry->d_inode->i_op &&
vp->v_file->f_dentry->d_inode->i_op->truncate_range) {
off_t end = bfp->l_start + bfp->l_len;
/*
* Judging from the code in shmem_truncate_range(),
* it seems the kernel expects the end offset to be
* inclusive and aligned to the end of a page.
*/
if (end % PAGE_SIZE != 0) {
end &= ~(off_t)(PAGE_SIZE - 1);
if (end <= bfp->l_start)
return (0);
}
--end;
vp->v_file->f_dentry->d_inode->i_op->truncate_range(
vp->v_file->f_dentry->d_inode,
bfp->l_start, end
);
return (0);
}
#endif
return (error);
}
EXPORT_SYMBOL(vn_space);
/* Function must be called while holding the vn_file_lock */
static file_t *
file_find(int fd)
{
file_t *fp;
ASSERT(spin_is_locked(&vn_file_lock));
list_for_each_entry(fp, &vn_file_list, f_list) {
if (fd == fp->f_fd && fp->f_task == current) {
ASSERT(atomic_read(&fp->f_ref) != 0);
return fp;
}
}
return NULL;
} /* file_find() */
file_t *
vn_getf(int fd)
{
struct kstat stat;
struct file *lfp;
file_t *fp;
vnode_t *vp;
int rc = 0;
/* Already open just take an extra reference */
spin_lock(&vn_file_lock);
fp = file_find(fd);
if (fp) {
atomic_inc(&fp->f_ref);
spin_unlock(&vn_file_lock);
return (fp);
}
spin_unlock(&vn_file_lock);
/* File was not yet opened create the object and setup */
fp = kmem_cache_alloc(vn_file_cache, KM_SLEEP);
if (fp == NULL)
goto out;
mutex_enter(&fp->f_lock);
fp->f_fd = fd;
fp->f_task = current;
fp->f_offset = 0;
atomic_inc(&fp->f_ref);
lfp = fget(fd);
if (lfp == NULL)
goto out_mutex;
vp = vn_alloc(KM_SLEEP);
if (vp == NULL)
goto out_fget;
#ifdef HAVE_2ARGS_VFS_GETATTR
rc = vfs_getattr(&lfp->f_path, &stat);
#else
rc = vfs_getattr(lfp->f_path.mnt, lfp->f_dentry, &stat);
#endif
if (rc)
goto out_vnode;
mutex_enter(&vp->v_lock);
vp->v_type = vn_mode_to_vtype(stat.mode);
vp->v_file = lfp;
mutex_exit(&vp->v_lock);
fp->f_vnode = vp;
fp->f_file = lfp;
/* Put it on the tracking list */
spin_lock(&vn_file_lock);
list_add(&fp->f_list, &vn_file_list);
spin_unlock(&vn_file_lock);
mutex_exit(&fp->f_lock);
return (fp);
out_vnode:
vn_free(vp);
out_fget:
fput(lfp);
out_mutex:
mutex_exit(&fp->f_lock);
kmem_cache_free(vn_file_cache, fp);
out:
return (NULL);
} /* getf() */
EXPORT_SYMBOL(getf);
static void releasef_locked(file_t *fp)
{
ASSERT(fp->f_file);
ASSERT(fp->f_vnode);
/* Unlinked from list, no refs, safe to free outside mutex */
fput(fp->f_file);
vn_free(fp->f_vnode);
kmem_cache_free(vn_file_cache, fp);
}
void
vn_releasef(int fd)
{
file_t *fp;
spin_lock(&vn_file_lock);
fp = file_find(fd);
if (fp) {
atomic_dec(&fp->f_ref);
if (atomic_read(&fp->f_ref) > 0) {
spin_unlock(&vn_file_lock);
return;
}
list_del(&fp->f_list);
releasef_locked(fp);
}
spin_unlock(&vn_file_lock);
return;
} /* releasef() */
EXPORT_SYMBOL(releasef);
static void
#ifdef HAVE_SET_FS_PWD_WITH_CONST
vn_set_fs_pwd(struct fs_struct *fs, const struct path *path)
#else
vn_set_fs_pwd(struct fs_struct *fs, struct path *path)
#endif /* HAVE_SET_FS_PWD_WITH_CONST */
{
struct path old_pwd;
#ifdef HAVE_FS_STRUCT_SPINLOCK
spin_lock(&fs->lock);
old_pwd = fs->pwd;
fs->pwd = *path;
path_get(path);
spin_unlock(&fs->lock);
#else
write_lock(&fs->lock);
old_pwd = fs->pwd;
fs->pwd = *path;
path_get(path);
write_unlock(&fs->lock);
#endif /* HAVE_FS_STRUCT_SPINLOCK */
if (old_pwd.dentry)
path_put(&old_pwd);
}
int
vn_set_pwd(const char *filename)
{
struct path path;
mm_segment_t saved_fs;
int rc;
/*
* user_path_dir() and __user_walk() both expect 'filename' to be
* a user space address so we must briefly increase the data segment
* size to ensure strncpy_from_user() does not fail with -EFAULT.
*/
saved_fs = get_fs();
set_fs(get_ds());
rc = user_path_dir(filename, &path);
if (rc)
goto out;
rc = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
if (rc)
goto dput_and_out;
vn_set_fs_pwd(current->fs, &path);
dput_and_out:
path_put(&path);
out:
set_fs(saved_fs);
return (-rc);
} /* vn_set_pwd() */
EXPORT_SYMBOL(vn_set_pwd);
static int
vn_cache_constructor(void *buf, void *cdrarg, int kmflags)
{
struct vnode *vp = buf;
mutex_init(&vp->v_lock, NULL, MUTEX_DEFAULT, NULL);
return (0);
} /* vn_cache_constructor() */
static void
vn_cache_destructor(void *buf, void *cdrarg)
{
struct vnode *vp = buf;
mutex_destroy(&vp->v_lock);
} /* vn_cache_destructor() */
static int
vn_file_cache_constructor(void *buf, void *cdrarg, int kmflags)
{
file_t *fp = buf;
atomic_set(&fp->f_ref, 0);
mutex_init(&fp->f_lock, NULL, MUTEX_DEFAULT, NULL);
INIT_LIST_HEAD(&fp->f_list);
return (0);
} /* file_cache_constructor() */
static void
vn_file_cache_destructor(void *buf, void *cdrarg)
{
file_t *fp = buf;
mutex_destroy(&fp->f_lock);
} /* vn_file_cache_destructor() */
int
spl_vn_init(void)
{
vn_cache = kmem_cache_create("spl_vn_cache",
sizeof(struct vnode), 64,
vn_cache_constructor,
vn_cache_destructor,
NULL, NULL, NULL, KMC_KMEM);
vn_file_cache = kmem_cache_create("spl_vn_file_cache",
sizeof(file_t), 64,
vn_file_cache_constructor,
vn_file_cache_destructor,
NULL, NULL, NULL, KMC_KMEM);
return (0);
} /* vn_init() */
void
spl_vn_fini(void)
{
file_t *fp, *next_fp;
int leaked = 0;
spin_lock(&vn_file_lock);
list_for_each_entry_safe(fp, next_fp, &vn_file_list, f_list) {
list_del(&fp->f_list);
releasef_locked(fp);
leaked++;
}
spin_unlock(&vn_file_lock);
if (leaked > 0)
printk(KERN_WARNING "WARNING: %d vnode files leaked\n", leaked);
kmem_cache_destroy(vn_file_cache);
kmem_cache_destroy(vn_cache);
return;
} /* vn_fini() */
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