switch generic_write_checks() to iocb and iter

... returning -E... upon error and amount of data left in iter after
(possible) truncation upon success.  Note, that normal case gives
a non-zero (positive) return value, so any tests for != 0 _must_ be
updated.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Conflicts:
	fs/ext4/file.c
This commit is contained in:
Al Viro
2015-04-09 12:55:47 -04:00
parent 90320251db
commit 3309dd04cb
14 changed files with 100 additions and 167 deletions

View File

@@ -2260,36 +2260,38 @@ EXPORT_SYMBOL(read_cache_page_gfp);
* Returns appropriate error code that caller should return or
* zero in case that write should be allowed.
*/
inline int generic_write_checks(struct file *file, loff_t *pos, size_t *count)
inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
unsigned long limit = rlimit(RLIMIT_FSIZE);
loff_t pos;
if (unlikely(*pos < 0))
return -EINVAL;
if (!iov_iter_count(from))
return 0;
/* FIXME: this is for backwards compatibility with 2.4 */
if (file->f_flags & O_APPEND)
*pos = i_size_read(inode);
iocb->ki_pos = i_size_read(inode);
pos = iocb->ki_pos;
if (limit != RLIM_INFINITY) {
if (*pos >= limit) {
if (iocb->ki_pos >= limit) {
send_sig(SIGXFSZ, current, 0);
return -EFBIG;
}
if (*count > limit - (typeof(limit))*pos)
*count = limit - (typeof(limit))*pos;
iov_iter_truncate(from, limit - (unsigned long)pos);
}
/*
* LFS rule
*/
if (unlikely(*pos + *count > MAX_NON_LFS &&
if (unlikely(pos + iov_iter_count(from) > MAX_NON_LFS &&
!(file->f_flags & O_LARGEFILE))) {
if (*pos >= MAX_NON_LFS)
if (pos >= MAX_NON_LFS)
return -EFBIG;
if (*count > MAX_NON_LFS - (unsigned long)*pos)
*count = MAX_NON_LFS - (unsigned long)*pos;
iov_iter_truncate(from, MAX_NON_LFS - (unsigned long)pos);
}
/*
@@ -2299,16 +2301,11 @@ inline int generic_write_checks(struct file *file, loff_t *pos, size_t *count)
* exceeded without writing data we send a signal and return EFBIG.
* Linus frestrict idea will clean these up nicely..
*/
if (unlikely(*pos >= inode->i_sb->s_maxbytes)) {
if (*count || *pos > inode->i_sb->s_maxbytes) {
return -EFBIG;
}
/* zero-length writes at ->s_maxbytes are OK */
}
if (unlikely(pos >= inode->i_sb->s_maxbytes))
return -EFBIG;
if (unlikely(*pos + *count > inode->i_sb->s_maxbytes))
*count = inode->i_sb->s_maxbytes - *pos;
return 0;
iov_iter_truncate(from, inode->i_sb->s_maxbytes - pos);
return iov_iter_count(from);
}
EXPORT_SYMBOL(generic_write_checks);
@@ -2618,14 +2615,11 @@ ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
ssize_t ret;
size_t count = iov_iter_count(from);
mutex_lock(&inode->i_mutex);
ret = generic_write_checks(file, &iocb->ki_pos, &count);
if (!ret && count) {
iov_iter_truncate(from, count);
ret = generic_write_checks(iocb, from);
if (ret > 0)
ret = __generic_file_write_iter(iocb, from);
}
mutex_unlock(&inode->i_mutex);
if (ret > 0) {