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Commit dae01d33 authored by Christoph Hellwig's avatar Christoph Hellwig
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[PATCH] read(v)/write(v) fixes 

Clean up vfs_readv/writev() interface and avoid code duplication.

Make kNFSd use the cleaned-up interfaces, and disable the code that
accesses the low-level readpage() function of the exported filesystem
(not allowed - many filesystems need extra setup, which is why we have
a separate ->sendpage() routine for that).
parent 8aa1cb75
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Inline Side-by-side
Showing with 50 additions and 131 deletions
fs/nfsd/vfs.c
View file @ dae01d33
......@@ -572,6 +572,7 @@ nfsd_get_raparms(dev_t dev, ino_t ino)
return ra;
}
#if 0 /* don't poke into fs code directly */
/*
* Grab and keep cached pages assosiated with a file in the svc_rqst
* so that they can be passed to the netowork sendmsg/sendpage routines
......@@ -626,6 +627,7 @@ nfsd_getpages(struct file *filp, struct svc_rqst *rqstp, unsigned long count)
retval = desc.error;
return retval;
}
#endif
/*
* Read data from a file. count must contain the requested read count
......@@ -658,13 +660,16 @@ nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
if (ra)
file.f_ra = ra->p_ra;
#if 0 /* don't poke into fs code directly */
if (inode->i_mapping->a_ops->readpage) {
file.f_pos = offset;
err = nfsd_getpages(&file, rqstp, *count);
} else {
} else
#endif
{
oldfs = get_fs();
set_fs(KERNEL_DS);
err = vfs_readv(&file, vec, vlen, *count, &offset);
err = vfs_readv(&file, vec, vlen, &offset);
set_fs(oldfs);
}
......@@ -740,7 +745,7 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
/* Write the data. */
oldfs = get_fs(); set_fs(KERNEL_DS);
err = vfs_writev(&file, vec, vlen, cnt, &offset);
err = vfs_writev(&file, vec, vlen, &offset);
if (err >= 0)
nfsdstats.io_write += cnt;
set_fs(oldfs);
......
fs/read_write.c
View file @ dae01d33
......@@ -207,53 +207,6 @@ ssize_t vfs_read(struct file *file, char *buf, size_t count, loff_t *pos)
return ret;
}
ssize_t vfs_readv(struct file *file, struct iovec *vec, int vlen, size_t count, loff_t *pos)
{
struct inode *inode = file->f_dentry->d_inode;
ssize_t ret;
if (!(file->f_mode & FMODE_READ))
return -EBADF;
if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read))
return -EINVAL;
ret = locks_verify_area(FLOCK_VERIFY_READ, inode, file, *pos, count);
if (!ret) {
ret = security_ops->file_permission (file, MAY_READ);
if (!ret) {
if (file->f_op->readv)
ret = file->f_op->readv(file, vec, vlen, pos);
else {
/* do it by hand */
struct iovec *vector = vec;
ret = 0;
while (vlen > 0) {
void * base = vector->iov_base;
size_t len = vector->iov_len;
ssize_t nr;
vector++;
vlen--;
if (file->f_op->read)
nr = file->f_op->read(file, base, len, pos);
else
nr = do_sync_read(file, base, len, pos);
if (nr < 0) {
if (!ret) ret = nr;
break;
}
ret += nr;
if (nr != len)
break;
}
}
if (ret > 0)
dnotify_parent(file->f_dentry, DN_ACCESS);
}
}
return ret;
}
ssize_t do_sync_write(struct file *filp, const char *buf, size_t len, loff_t *ppos)
{
struct kiocb kiocb;
......@@ -294,53 +247,6 @@ ssize_t vfs_write(struct file *file, const char *buf, size_t count, loff_t *pos)
return ret;
}
ssize_t vfs_writev(struct file *file, const struct iovec *vec, int vlen, size_t count, loff_t *pos)
{
struct inode *inode = file->f_dentry->d_inode;
ssize_t ret;
if (!(file->f_mode & FMODE_WRITE))
return -EBADF;
if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write))
return -EINVAL;
ret = locks_verify_area(FLOCK_VERIFY_WRITE, inode, file, *pos, count);
if (!ret) {
ret = security_ops->file_permission (file, MAY_WRITE);
if (!ret) {
if (file->f_op->writev)
ret = file->f_op->writev(file, vec, vlen, pos);
else {
/* do it by hand */
const struct iovec *vector = vec;
ret = 0;
while (vlen > 0) {
void * base = vector->iov_base;
size_t len = vector->iov_len;
ssize_t nr;
vector++;
vlen--;
if (file->f_op->write)
nr = file->f_op->write(file, base, len, pos);
else
nr = do_sync_write(file, base, len, pos);
if (nr < 0) {
if (!ret) ret = nr;
break;
}
ret += nr;
if (nr != len)
break;
}
}
if (ret > 0)
dnotify_parent(file->f_dentry, DN_MODIFY);
}
}
return ret;
}
asmlinkage ssize_t sys_read(unsigned int fd, char * buf, size_t count)
{
struct file *file;
......@@ -427,7 +333,7 @@ unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to)
static ssize_t do_readv_writev(int type, struct file *file,
const struct iovec * vector,
unsigned long nr_segs)
unsigned long nr_segs, loff_t *pos)
{
typedef ssize_t (*io_fn_t)(struct file *, char *, size_t, loff_t *);
typedef ssize_t (*iov_fn_t)(struct file *, const struct iovec *, unsigned long, loff_t *);
......@@ -496,7 +402,7 @@ static ssize_t do_readv_writev(int type, struct file *file,
/* VERIFY_WRITE actually means a read, as we write to user space */
ret = locks_verify_area((type == READ
? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE),
inode, file, file->f_pos, tot_len);
inode, file, *pos, tot_len);
if (ret)
goto out;
......@@ -509,7 +415,7 @@ static ssize_t do_readv_writev(int type, struct file *file,
fnv = file->f_op->writev;
}
if (fnv) {
ret = fnv(file, iov, nr_segs, &file->f_pos);
ret = fnv(file, iov, nr_segs, pos);
goto out;
}
......@@ -526,7 +432,7 @@ static ssize_t do_readv_writev(int type, struct file *file,
vector++;
nr_segs--;
nr = fn(file, base, len, &file->f_pos);
nr = fn(file, base, len, pos);
if (nr < 0) {
if (!ret) ret = nr;
......@@ -545,50 +451,56 @@ static ssize_t do_readv_writev(int type, struct file *file,
return ret;
}
ssize_t vfs_readv(struct file *file, const struct iovec *vec,
unsigned long vlen, loff_t *pos)
{
if (!(file->f_mode & FMODE_READ))
return -EBADF;
if (!file->f_op || (!file->f_op->readv && !file->f_op->read))
return -EINVAL;
asmlinkage ssize_t
sys_readv(unsigned long fd, const struct iovec *vector, unsigned long nr_segs)
return do_readv_writev(READ, file, vec, vlen, pos);
}
ssize_t vfs_writev(struct file *file, const struct iovec *vec,
unsigned long vlen, loff_t *pos)
{
struct file * file;
ssize_t ret;
if (!(file->f_mode & FMODE_WRITE))
return -EBADF;
if (!file->f_op || (!file->f_op->writev && !file->f_op->write))
return -EINVAL;
return do_readv_writev(WRITE, file, vec, vlen, pos);
}
ret = -EBADF;
asmlinkage ssize_t
sys_readv(unsigned long fd, const struct iovec *vec, unsigned long vlen)
{
struct file *file;
ssize_t ret = -EBADF;
file = fget(fd);
if (!file)
goto bad_file;
if (file->f_op && (file->f_mode & FMODE_READ) &&
(file->f_op->readv || file->f_op->read)) {
ret = security_ops->file_permission (file, MAY_READ);
if (!ret)
ret = do_readv_writev(READ, file, vector, nr_segs);
}
if (file) {
ret = vfs_readv(file, vec, vlen, &file->f_pos);
fput(file);
}
bad_file:
return ret;
}
asmlinkage ssize_t
sys_writev(unsigned long fd, const struct iovec * vector, unsigned long nr_segs)
sys_writev(unsigned long fd, const struct iovec *vec, unsigned long vlen)
{
struct file * file;
ssize_t ret;
struct file *file;
ssize_t ret = -EBADF;
ret = -EBADF;
file = fget(fd);
if (!file)
goto bad_file;
if (file->f_op && (file->f_mode & FMODE_WRITE) &&
(file->f_op->writev || file->f_op->write)) {
ret = security_ops->file_permission (file, MAY_WRITE);
if (!ret)
ret = do_readv_writev(WRITE, file, vector, nr_segs);
}
if (file) {
ret = vfs_writev(file, vec, vlen, &file->f_pos);
fput(file);
}
bad_file:
return ret;
}
......
include/linux/fs.h
View file @ dae01d33
......@@ -793,8 +793,10 @@ struct seq_file;
extern ssize_t vfs_read(struct file *, char *, size_t, loff_t *);
extern ssize_t vfs_write(struct file *, const char *, size_t, loff_t *);
extern ssize_t vfs_readv(struct file *, struct iovec *, int, size_t, loff_t *);
extern ssize_t vfs_writev(struct file *, const struct iovec *, int, size_t, loff_t *);
extern ssize_t vfs_readv(struct file *, const struct iovec *,
unsigned long, loff_t *);
extern ssize_t vfs_writev(struct file *, const struct iovec *,
unsigned long, loff_t *);
/*
* NOTE: write_inode, delete_inode, clear_inode, put_inode can be called
......
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