X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fread_write.c;h=9d1e76bb9ee147b8236630ba953a53873b1847d4;hb=3cef9ab266a932899e756f7e1ea7a988a97bf3b2;hp=1c177f29e1b72be0aa63f38496ed81727d01f653;hpb=19295529db35381d46dbaf246f69b4e3b3393996;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/read_write.c b/fs/read_write.c
index 1c177f2..9d1e76b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -31,57 +31,71 @@ const struct file_operations generic_ro_fops = {
 
 EXPORT_SYMBOL(generic_ro_fops);
 
-loff_t generic_file_llseek(struct file *file, loff_t offset, int origin)
+/**
+ * generic_file_llseek_unlocked - lockless generic llseek implementation
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @origin:	type of seek
+ *
+ * Updates the file offset to the value specified by @offset and @origin.
+ * Locking must be provided by the caller.
+ */
+loff_t
+generic_file_llseek_unlocked(struct file *file, loff_t offset, int origin)
 {
-	long long retval;
 	struct inode *inode = file->f_mapping->host;
 
-	mutex_lock(&inode->i_mutex);
 	switch (origin) {
-		case SEEK_END:
-			offset += inode->i_size;
-			break;
-		case SEEK_CUR:
-			offset += file->f_pos;
-	}
-	retval = -EINVAL;
-	if (offset>=0 && offset<=inode->i_sb->s_maxbytes) {
-		if (offset != file->f_pos) {
-			file->f_pos = offset;
-			file->f_version = 0;
-		}
-		retval = offset;
+	case SEEK_END:
+		offset += inode->i_size;
+		break;
+	case SEEK_CUR:
+		/*
+		 * Here we special-case the lseek(fd, 0, SEEK_CUR)
+		 * position-querying operation.  Avoid rewriting the "same"
+		 * f_pos value back to the file because a concurrent read(),
+		 * write() or lseek() might have altered it
+		 */
+		if (offset == 0)
+			return file->f_pos;
+		offset += file->f_pos;
+		break;
+	}
+
+	if (offset < 0 || offset > inode->i_sb->s_maxbytes)
+		return -EINVAL;
+
+	/* Special lock needed here? */
+	if (offset != file->f_pos) {
+		file->f_pos = offset;
+		file->f_version = 0;
 	}
-	mutex_unlock(&inode->i_mutex);
-	return retval;
-}
 
-EXPORT_SYMBOL(generic_file_llseek);
+	return offset;
+}
+EXPORT_SYMBOL(generic_file_llseek_unlocked);
 
-loff_t remote_llseek(struct file *file, loff_t offset, int origin)
+/**
+ * generic_file_llseek - generic llseek implementation for regular files
+ * @file:	file structure to seek on
+ * @offset:	file offset to seek to
+ * @origin:	type of seek
+ *
+ * This is a generic implemenation of ->llseek useable for all normal local
+ * filesystems.  It just updates the file offset to the value specified by
+ * @offset and @origin under i_mutex.
+ */
+loff_t generic_file_llseek(struct file *file, loff_t offset, int origin)
 {
-	long long retval;
+	loff_t rval;
 
-	lock_kernel();
-	switch (origin) {
-		case SEEK_END:
-			offset += i_size_read(file->f_path.dentry->d_inode);
-			break;
-		case SEEK_CUR:
-			offset += file->f_pos;
-	}
-	retval = -EINVAL;
-	if (offset>=0 && offset<=file->f_path.dentry->d_inode->i_sb->s_maxbytes) {
-		if (offset != file->f_pos) {
-			file->f_pos = offset;
-			file->f_version = 0;
-		}
-		retval = offset;
-	}
-	unlock_kernel();
-	return retval;
+	mutex_lock(&file->f_dentry->d_inode->i_mutex);
+	rval = generic_file_llseek_unlocked(file, offset, origin);
+	mutex_unlock(&file->f_dentry->d_inode->i_mutex);
+
+	return rval;
 }
-EXPORT_SYMBOL(remote_llseek);
+EXPORT_SYMBOL(generic_file_llseek);
 
 loff_t no_llseek(struct file *file, loff_t offset, int origin)
 {
@@ -91,7 +105,7 @@ EXPORT_SYMBOL(no_llseek);
 
 loff_t default_llseek(struct file *file, loff_t offset, int origin)
 {
-	long long retval;
+	loff_t retval;
 
 	lock_kernel();
 	switch (origin) {
@@ -99,6 +113,10 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
 			offset += i_size_read(file->f_path.dentry->d_inode);
 			break;
 		case SEEK_CUR:
+			if (offset == 0) {
+				retval = file->f_pos;
+				goto out;
+			}
 			offset += file->f_pos;
 	}
 	retval = -EINVAL;
@@ -109,6 +127,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
 		}
 		retval = offset;
 	}
+out:
 	unlock_kernel();
 	return retval;
 }
@@ -128,7 +147,7 @@ loff_t vfs_llseek(struct file *file, loff_t offset, int origin)
 }
 EXPORT_SYMBOL(vfs_llseek);
 
-asmlinkage off_t sys_lseek(unsigned int fd, off_t offset, unsigned int origin)
+SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, origin)
 {
 	off_t retval;
 	struct file * file;
@@ -152,9 +171,9 @@ bad:
 }
 
 #ifdef __ARCH_WANT_SYS_LLSEEK
-asmlinkage long sys_llseek(unsigned int fd, unsigned long offset_high,
-			   unsigned long offset_low, loff_t __user * result,
-			   unsigned int origin)
+SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
+		unsigned long, offset_low, loff_t __user *, result,
+		unsigned int, origin)
 {
 	int retval;
 	struct file * file;
@@ -350,7 +369,7 @@ static inline void file_pos_write(struct file *file, loff_t pos)
 	file->f_pos = pos;
 }
 
-asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count)
+SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
 {
 	struct file *file;
 	ssize_t ret = -EBADF;
@@ -366,9 +385,9 @@ asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count)
 
 	return ret;
 }
-EXPORT_UNUSED_SYMBOL_GPL(sys_read); /* to be deleted for 2.6.25 */
 
-asmlinkage ssize_t sys_write(unsigned int fd, const char __user * buf, size_t count)
+SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf,
+		size_t, count)
 {
 	struct file *file;
 	ssize_t ret = -EBADF;
@@ -385,8 +404,8 @@ asmlinkage ssize_t sys_write(unsigned int fd, const char __user * buf, size_t co
 	return ret;
 }
 
-asmlinkage ssize_t sys_pread64(unsigned int fd, char __user *buf,
-			     size_t count, loff_t pos)
+SYSCALL_DEFINE(pread64)(unsigned int fd, char __user *buf,
+			size_t count, loff_t pos)
 {
 	struct file *file;
 	ssize_t ret = -EBADF;
@@ -405,9 +424,17 @@ asmlinkage ssize_t sys_pread64(unsigned int fd, char __user *buf,
 
 	return ret;
 }
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_pread64(long fd, long buf, long count, loff_t pos)
+{
+	return SYSC_pread64((unsigned int) fd, (char __user *) buf,
+			    (size_t) count, pos);
+}
+SYSCALL_ALIAS(sys_pread64, SyS_pread64);
+#endif
 
-asmlinkage ssize_t sys_pwrite64(unsigned int fd, const char __user *buf,
-			      size_t count, loff_t pos)
+SYSCALL_DEFINE(pwrite64)(unsigned int fd, const char __user *buf,
+			 size_t count, loff_t pos)
 {
 	struct file *file;
 	ssize_t ret = -EBADF;
@@ -426,6 +453,14 @@ asmlinkage ssize_t sys_pwrite64(unsigned int fd, const char __user *buf,
 
 	return ret;
 }
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_pwrite64(long fd, long buf, long count, loff_t pos)
+{
+	return SYSC_pwrite64((unsigned int) fd, (const char __user *) buf,
+			     (size_t) count, pos);
+}
+SYSCALL_ALIAS(sys_pwrite64, SyS_pwrite64);
+#endif
 
 /*
  * Reduce an iovec's length in-place.  Return the resulting number of segments
@@ -654,8 +689,8 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 
 EXPORT_SYMBOL(vfs_writev);
 
-asmlinkage ssize_t
-sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen)
+SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen)
 {
 	struct file *file;
 	ssize_t ret = -EBADF;
@@ -675,8 +710,8 @@ sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen)
 	return ret;
 }
 
-asmlinkage ssize_t
-sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen)
+SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen)
 {
 	struct file *file;
 	ssize_t ret = -EBADF;
@@ -696,6 +731,62 @@ sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen)
 	return ret;
 }
 
+static inline loff_t pos_from_hilo(unsigned long high, unsigned long low)
+{
+#define HALF_LONG_BITS (BITS_PER_LONG / 2)
+	return (((loff_t)high << HALF_LONG_BITS) << HALF_LONG_BITS) | low;
+}
+
+SYSCALL_DEFINE5(preadv, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+{
+	loff_t pos = pos_from_hilo(pos_h, pos_l);
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		ret = -ESPIPE;
+		if (file->f_mode & FMODE_PREAD)
+			ret = vfs_readv(file, vec, vlen, &pos);
+		fput_light(file, fput_needed);
+	}
+
+	if (ret > 0)
+		add_rchar(current, ret);
+	inc_syscr(current);
+	return ret;
+}
+
+SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec,
+		unsigned long, vlen, unsigned long, pos_l, unsigned long, pos_h)
+{
+	loff_t pos = pos_from_hilo(pos_h, pos_l);
+	struct file *file;
+	ssize_t ret = -EBADF;
+	int fput_needed;
+
+	if (pos < 0)
+		return -EINVAL;
+
+	file = fget_light(fd, &fput_needed);
+	if (file) {
+		ret = -ESPIPE;
+		if (file->f_mode & FMODE_PWRITE)
+			ret = vfs_writev(file, vec, vlen, &pos);
+		fput_light(file, fput_needed);
+	}
+
+	if (ret > 0)
+		add_wchar(current, ret);
+	inc_syscw(current);
+	return ret;
+}
+
 static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
 			   size_t count, loff_t max)
 {
@@ -794,7 +885,7 @@ out:
 	return retval;
 }
 
-asmlinkage ssize_t sys_sendfile(int out_fd, int in_fd, off_t __user *offset, size_t count)
+SYSCALL_DEFINE4(sendfile, int, out_fd, int, in_fd, off_t __user *, offset, size_t, count)
 {
 	loff_t pos;
 	off_t off;
@@ -813,7 +904,7 @@ asmlinkage ssize_t sys_sendfile(int out_fd, int in_fd, off_t __user *offset, siz
 	return do_sendfile(out_fd, in_fd, NULL, count, 0);
 }
 
-asmlinkage ssize_t sys_sendfile64(int out_fd, int in_fd, loff_t __user *offset, size_t count)
+SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd, loff_t __user *, offset, size_t, count)
 {
 	loff_t pos;
 	ssize_t ret;