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mirror_zfs/module/spl/spl-vnode.c
Brian Behlendorf 6bf4d76f47 Linux Compat: inode->i_mutex/i_sem 
Create spl_inode_lock/spl_inode_unlock compability macros to simply
access to the inode mutex/sem.  This avoids the need to have to ugly
up the code with the required #define's at every call site.  At the
moment the SPL only uses this in one place but higher layers can
benefit from the macro.
2011-01-11 12:14:48 -08:00

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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://github.com/behlendorf/spl/>.
*
* 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/vnode.h>
#include <spl-debug.h>
#ifdef SS_DEBUG_SUBSYS
#undef SS_DEBUG_SUBSYS
#endif
#define SS_DEBUG_SUBSYS SS_VNODE
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 spinlock_t vn_file_lock = SPIN_LOCK_UNLOCKED;
static LIST_HEAD(vn_file_list);
static vtype_t
vn_get_sol_type(umode_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_get_sol_type() */
vnode_t *
vn_alloc(int flag)
{
vnode_t *vp;
SENTRY;
vp = kmem_cache_alloc(vn_cache, flag);
if (vp != NULL) {
vp->v_file = NULL;
vp->v_type = 0;
}
SRETURN(vp);
} /* vn_alloc() */
EXPORT_SYMBOL(vn_alloc);
void
vn_free(vnode_t *vp)
{
SENTRY;
kmem_cache_free(vn_cache, vp);
SEXIT;
} /* 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;
SENTRY;
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))
SRETURN(-PTR_ERR(fp));
rc = vfs_getattr(fp->f_vfsmnt, fp->f_dentry, &stat);
if (rc) {
filp_close(fp, 0);
SRETURN(-rc);
}
vp = vn_alloc(KM_SLEEP);
if (!vp) {
filp_close(fp, 0);
SRETURN(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_get_sol_type(stat.mode);
vp->v_file = fp;
vp->v_gfp_mask = saved_gfp;
*vpp = vp;
mutex_exit(&vp->v_lock);
SRETURN(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;
SENTRY;
ASSERT(vp == rootdir);
len = strlen(path) + 2;
realpath = kmalloc(len, GFP_KERNEL);
if (!realpath)
SRETURN(ENOMEM);
(void)snprintf(realpath, len, "/%s", path);
rc = vn_open(realpath, seg, flags, mode, vpp, x1, x2);
kfree(realpath);
SRETURN(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;
SENTRY;
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);
if (rc < 0)
SRETURN(-rc);
if (residp) {
*residp = len - rc;
} else {
if (rc != len)
SRETURN(EIO);
}
SRETURN(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;
SENTRY;
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);
SRETURN(-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, caller_context_t *ct)
{
return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0);
}
EXPORT_SYMBOL(vn_seek);
static struct dentry *
vn_lookup_hash(struct nameidata *nd)
{
return lookup_one_len((const char *)nd->last.name,
nd->nd_dentry, nd->last.len);
} /* lookup_hash() */
static void
vn_path_release(struct nameidata *nd)
{
dput(nd->nd_dentry);
mntput(nd->nd_mnt);
}
/* Modified do_unlinkat() from linux/fs/namei.c, only uses exported symbols */
int
vn_remove(const char *path, uio_seg_t seg, int flags)
{
struct dentry *dentry;
struct nameidata nd;
struct inode *inode = NULL;
int rc = 0;
SENTRY;
ASSERT(seg == UIO_SYSSPACE);
ASSERT(flags == RMFILE);
rc = path_lookup(path, LOOKUP_PARENT, &nd);
if (rc)
SGOTO(exit, rc);
rc = -EISDIR;
if (nd.last_type != LAST_NORM)
SGOTO(exit1, rc);
spl_inode_lock_nested(nd.nd_dentry->d_inode, I_MUTEX_PARENT);
dentry = vn_lookup_hash(&nd);
rc = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
/* Why not before? Because we want correct rc value */
if (nd.last.name[nd.last.len])
SGOTO(slashes, rc);
inode = dentry->d_inode;
if (inode)
atomic_inc(&inode->i_count);
#ifdef HAVE_2ARGS_VFS_UNLINK
rc = vfs_unlink(nd.nd_dentry->d_inode, dentry);
#else
rc = vfs_unlink(nd.nd_dentry->d_inode, dentry, nd.nd_mnt);
#endif /* HAVE_2ARGS_VFS_UNLINK */
exit2:
dput(dentry);
}
spl_inode_unlock(nd.nd_dentry->d_inode);
if (inode)
iput(inode); /* truncate the inode here */
exit1:
vn_path_release(&nd);
exit:
SRETURN(-rc);
slashes:
rc = !dentry->d_inode ? -ENOENT :
S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR;
SGOTO(exit2, rc);
} /* vn_remove() */
EXPORT_SYMBOL(vn_remove);
/* Modified do_rename() from linux/fs/namei.c, only uses exported symbols */
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 nameidata oldnd, newnd;
int rc = 0;
SENTRY;
rc = path_lookup(oldname, LOOKUP_PARENT, &oldnd);
if (rc)
SGOTO(exit, rc);
rc = path_lookup(newname, LOOKUP_PARENT, &newnd);
if (rc)
SGOTO(exit1, rc);
rc = -EXDEV;
if (oldnd.nd_mnt != newnd.nd_mnt)
SGOTO(exit2, rc);
old_dir = oldnd.nd_dentry;
rc = -EBUSY;
if (oldnd.last_type != LAST_NORM)
SGOTO(exit2, rc);
new_dir = newnd.nd_dentry;
if (newnd.last_type != LAST_NORM)
SGOTO(exit2, rc);
trap = lock_rename(new_dir, old_dir);
old_dentry = vn_lookup_hash(&oldnd);
rc = PTR_ERR(old_dentry);
if (IS_ERR(old_dentry))
SGOTO(exit3, rc);
/* source must exist */
rc = -ENOENT;
if (!old_dentry->d_inode)
SGOTO(exit4, rc);
/* unless the source is a directory trailing slashes give -ENOTDIR */
if (!S_ISDIR(old_dentry->d_inode->i_mode)) {
rc = -ENOTDIR;
if (oldnd.last.name[oldnd.last.len])
SGOTO(exit4, rc);
if (newnd.last.name[newnd.last.len])
SGOTO(exit4, rc);
}
/* source should not be ancestor of target */
rc = -EINVAL;
if (old_dentry == trap)
SGOTO(exit4, rc);
new_dentry = vn_lookup_hash(&newnd);
rc = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
SGOTO(exit4, rc);
/* target should not be an ancestor of source */
rc = -ENOTEMPTY;
if (new_dentry == trap)
SGOTO(exit5, rc);
#ifdef HAVE_4ARGS_VFS_RENAME
rc = vfs_rename(old_dir->d_inode, old_dentry,
new_dir->d_inode, new_dentry);
#else
rc = vfs_rename(old_dir->d_inode, old_dentry, oldnd.nd_mnt,
new_dir->d_inode, new_dentry, newnd.nd_mnt);
#endif /* HAVE_4ARGS_VFS_RENAME */
exit5:
dput(new_dentry);
exit4:
dput(old_dentry);
exit3:
unlock_rename(new_dir, old_dir);
exit2:
vn_path_release(&newnd);
exit1:
vn_path_release(&oldnd);
exit:
SRETURN(-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;
SENTRY;
ASSERT(vp);
ASSERT(vp->v_file);
ASSERT(vap);
fp = vp->v_file;
rc = vfs_getattr(fp->f_vfsmnt, fp->f_dentry, &stat);
if (rc)
SRETURN(-rc);
vap->va_type = vn_get_sol_type(stat.mode);
vap->va_mode = stat.mode;
vap->va_uid = stat.uid;
vap->va_gid = stat.gid;
vap->va_fsid = 0;
vap->va_nodeid = stat.ino;
vap->va_nlink = stat.nlink;
vap->va_size = stat.size;
vap->va_blocksize = stat.blksize;
vap->va_atime.tv_sec = stat.atime.tv_sec;
vap->va_atime.tv_usec = stat.atime.tv_nsec / NSEC_PER_USEC;
vap->va_mtime.tv_sec = stat.mtime.tv_sec;
vap->va_mtime.tv_usec = stat.mtime.tv_nsec / NSEC_PER_USEC;
vap->va_ctime.tv_sec = stat.ctime.tv_sec;
vap->va_ctime.tv_usec = stat.ctime.tv_nsec / NSEC_PER_USEC;
vap->va_rdev = stat.rdev;
vap->va_blocks = stat.blocks;
SRETURN(0);
}
EXPORT_SYMBOL(vn_getattr);
int vn_fsync(vnode_t *vp, int flags, void *x3, void *x4)
{
int datasync = 0;
SENTRY;
ASSERT(vp);
ASSERT(vp->v_file);
if (flags & FDSYNC)
datasync = 1;
SRETURN(-spl_filp_fsync(vp->v_file, datasync));
} /* vn_fsync() */
EXPORT_SYMBOL(vn_fsync);
/* 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) {
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;
SENTRY;
/* 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);
SRETURN(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)
SGOTO(out, rc);
mutex_enter(&fp->f_lock);
fp->f_fd = fd;
fp->f_offset = 0;
atomic_inc(&fp->f_ref);
lfp = fget(fd);
if (lfp == NULL)
SGOTO(out_mutex, rc);
vp = vn_alloc(KM_SLEEP);
if (vp == NULL)
SGOTO(out_fget, rc);
if (vfs_getattr(lfp->f_vfsmnt, lfp->f_dentry, &stat))
SGOTO(out_vnode, rc);
mutex_enter(&vp->v_lock);
vp->v_type = vn_get_sol_type(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);
SRETURN(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:
SRETURN(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;
SENTRY;
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);
SEXIT;
return;
}
list_del(&fp->f_list);
releasef_locked(fp);
}
spin_unlock(&vn_file_lock);
SEXIT;
return;
} /* releasef() */
EXPORT_SYMBOL(releasef);
#ifndef HAVE_SET_FS_PWD
# ifdef HAVE_2ARGS_SET_FS_PWD
/* Used from 2.6.25 - 2.6.31+ */
void
set_fs_pwd(struct fs_struct *fs, struct path *path)
{
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);
}
# else
/* Used from 2.6.11 - 2.6.24 */
void
set_fs_pwd(struct fs_struct *fs, struct vfsmount *mnt, struct dentry *dentry)
{
struct dentry *old_pwd;
struct vfsmount *old_pwdmnt;
write_lock(&fs->lock);
old_pwd = fs->pwd;
old_pwdmnt = fs->pwdmnt;
fs->pwdmnt = mntget(mnt);
fs->pwd = dget(dentry);
write_unlock(&fs->lock);
if (old_pwd) {
dput(old_pwd);
mntput(old_pwdmnt);
}
}
# endif /* HAVE_2ARGS_SET_FS_PWD */
#endif /* HAVE_SET_FS_PWD */
int
vn_set_pwd(const char *filename)
{
#if defined(HAVE_2ARGS_SET_FS_PWD) && defined(HAVE_USER_PATH_DIR)
struct path path;
#else
struct nameidata nd;
#endif /* HAVE_2ARGS_SET_FS_PWD */
mm_segment_t saved_fs;
int rc;
SENTRY;
/*
* 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());
#ifdef HAVE_2ARGS_SET_FS_PWD
# ifdef HAVE_USER_PATH_DIR
rc = user_path_dir(filename, &path);
if (rc)
SGOTO(out, rc);
rc = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
if (rc)
SGOTO(dput_and_out, rc);
set_fs_pwd(current->fs, &path);
dput_and_out:
path_put(&path);
# else
rc = __user_walk(filename,
LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd);
if (rc)
SGOTO(out, rc);
rc = vfs_permission(&nd, MAY_EXEC);
if (rc)
SGOTO(dput_and_out, rc);
set_fs_pwd(current->fs, &nd.path);
dput_and_out:
path_put(&nd.path);
# endif /* HAVE_USER_PATH_DIR */
#else
rc = __user_walk(filename,
LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_CHDIR, &nd);
if (rc)
SGOTO(out, rc);
rc = vfs_permission(&nd, MAY_EXEC);
if (rc)
SGOTO(dput_and_out, rc);
set_fs_pwd(current->fs, nd.nd_mnt, nd.nd_dentry);
dput_and_out:
vn_path_release(&nd);
#endif /* HAVE_2ARGS_SET_FS_PWD */
out:
set_fs(saved_fs);
SRETURN(-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
vn_init(void)
{
SENTRY;
vn_cache = kmem_cache_create("spl_vn_cache",
sizeof(struct vnode), 64,
vn_cache_constructor,
vn_cache_destructor,
NULL, NULL, NULL, 0);
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, 0);
SRETURN(0);
} /* vn_init() */
void
vn_fini(void)
{
file_t *fp, *next_fp;
int leaked = 0;
SENTRY;
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++;
}
kmem_cache_destroy(vn_file_cache);
vn_file_cache = NULL;
spin_unlock(&vn_file_lock);
if (leaked > 0)
SWARN("Warning %d files leaked\n", leaked);
kmem_cache_destroy(vn_cache);
SEXIT;
return;
} /* vn_fini() */
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