mirror_zfs/module/spl/spl-vnode.c
Brian Behlendorf 8d9a23e82c Retire legacy debugging infrastructure
When the SPL was originally written Linux tracepoints were still
in their infancy.  Therefore, an entire debugging subsystem was
added to facilite tracing which served us well for many years.

Now that Linux tracepoints have matured they provide all the
functionality of the previous tracing subsystem.  Rather than
maintain parallel functionality it makes sense to fully adopt
tracepoints.  Therefore, this patch retires the legacy debugging
infrastructure.

See zfsonlinux/zfs@bc9f413 for the tracepoint changes.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #408
2014-11-19 10:35:07 -08:00

878 lines
18 KiB
C

/*****************************************************************************\
* 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 <linux/falloc.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() */