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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Browse source 
Pull third hunk of vfs changes from Al Viro:
 "This contains the ->direct_IO() changes from Omar + saner
  generic_write_checks() + dealing with fcntl()/{read,write}() races
  (mirroring O_APPEND/O_DIRECT into iocb->ki_flags and instead of
  repeatedly looking at ->f_flags, which can be changed by fcntl(2),
  check ->ki_flags - which cannot) + infrastructure bits for dhowells'
  d_inode annotations + Christophs switch of /dev/loop to
  vfs_iter_write()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (30 commits)
  block: loop: switch to VFS ITER_BVEC
  configfs: Fix inconsistent use of file_inode() vs file->f_path.dentry->d_inode
  VFS: Make pathwalk use d_is_reg() rather than S_ISREG()
  VFS: Fix up debugfs to use d_is_dir() in place of S_ISDIR()
  VFS: Combine inode checks with d_is_negative() and d_is_positive() in pathwalk
  NFS: Don't use d_inode as a variable name
  VFS: Impose ordering on accesses of d_inode and d_flags
  VFS: Add owner-filesystem positive/negative dentry checks
  nfs: generic_write_checks() shouldn't be done on swapout...
  ocfs2: use __generic_file_write_iter()
  mirror O_APPEND and O_DIRECT into iocb->ki_flags
  switch generic_write_checks() to iocb and iter
  ocfs2: move generic_write_checks() before the alignment checks
  ocfs2_file_write_iter: stop messing with ppos
  udf_file_write_iter: reorder and simplify
  fuse: ->direct_IO() doesn't need generic_write_checks()
  ext4_file_write_iter: move generic_write_checks() up
  xfs_file_aio_write_checks: switch to iocb/iov_iter
  generic_write_checks(): drop isblk argument
  blkdev_write_iter: expand generic_file_checks() call in there
  ...
This commit is contained in:
Linus Torvalds 2015-04-16 23:27:56 -04:00
commit 4fc8adcfec
55 changed files with 700 additions and 870 deletions
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114
mm/filemap.c
View file

@ -1693,7 +1693,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
loff_t *ppos = &iocb->ki_pos;
loff_t pos = *ppos;
if (io_is_direct(file)) {
if (iocb->ki_flags & IOCB_DIRECT) {
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
size_t count = iov_iter_count(iter);
@ -1706,7 +1706,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
pos + count - 1);
if (!retval) {
struct iov_iter data = *iter;
retval = mapping->a_ops->direct_IO(READ, iocb, &data, pos);
retval = mapping->a_ops->direct_IO(iocb, &data, pos);
}
if (retval > 0) {
@ -2259,41 +2259,38 @@ 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, int isblk)
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;
if (!isblk) {
/* FIXME: this is for backwards compatibility with 2.4 */
if (file->f_flags & O_APPEND)
*pos = i_size_read(inode);
/* FIXME: this is for backwards compatibility with 2.4 */
if (iocb->ki_flags & IOCB_APPEND)
iocb->ki_pos = i_size_read(inode);
if (limit != RLIM_INFINITY) {
if (*pos >= limit) {
send_sig(SIGXFSZ, current, 0);
return -EFBIG;
}
if (*count > limit - (typeof(limit))*pos) {
*count = limit - (typeof(limit))*pos;
}
pos = iocb->ki_pos;
if (limit != RLIM_INFINITY) {
if (iocb->ki_pos >= limit) {
send_sig(SIGXFSZ, current, 0);
return -EFBIG;
}
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);
}
/*
@ -2303,34 +2300,11 @@ inline int generic_write_checks(struct file *file, loff_t *pos, size_t *count, i
* exceeded without writing data we send a signal and return EFBIG.
* Linus frestrict idea will clean these up nicely..
*/
if (likely(!isblk)) {
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;
} else {
#ifdef CONFIG_BLOCK
loff_t isize;
if (bdev_read_only(I_BDEV(inode)))
return -EPERM;
isize = i_size_read(inode);
if (*pos >= isize) {
if (*count || *pos > isize)
return -ENOSPC;
}
if (*pos + *count > isize)
*count = isize - *pos;
#else
return -EPERM;
#endif
}
return 0;
iov_iter_truncate(from, inode->i_sb->s_maxbytes - pos);
return iov_iter_count(from);
}
EXPORT_SYMBOL(generic_write_checks);
@ -2394,7 +2368,7 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos)
}
data = *from;
written = mapping->a_ops->direct_IO(WRITE, iocb, &data, pos);
written = mapping->a_ops->direct_IO(iocb, &data, pos);
/*
* Finally, try again to invalidate clean pages which might have been
@ -2556,23 +2530,12 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
struct file *file = iocb->ki_filp;
struct address_space * mapping = file->f_mapping;
struct inode *inode = mapping->host;
loff_t pos = iocb->ki_pos;
ssize_t written = 0;
ssize_t err;
ssize_t status;
size_t count = iov_iter_count(from);
/* We can write back this queue in page reclaim */
current->backing_dev_info = inode_to_bdi(inode);
err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
if (err)
goto out;
if (count == 0)
goto out;
iov_iter_truncate(from, count);
err = file_remove_suid(file);
if (err)
goto out;
@ -2581,10 +2544,10 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
if (err)
goto out;
if (io_is_direct(file)) {
loff_t endbyte;
if (iocb->ki_flags & IOCB_DIRECT) {
loff_t pos, endbyte;
written = generic_file_direct_write(iocb, from, pos);
written = generic_file_direct_write(iocb, from, iocb->ki_pos);
/*
* If the write stopped short of completing, fall back to
* buffered writes. Some filesystems do this for writes to
@ -2592,13 +2555,10 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
* not succeed (even if it did, DAX does not handle dirty
* page-cache pages correctly).
*/
if (written < 0 || written == count || IS_DAX(inode))
if (written < 0 || !iov_iter_count(from) || IS_DAX(inode))
goto out;
pos += written;
count -= written;
status = generic_perform_write(file, from, pos);
status = generic_perform_write(file, from, pos = iocb->ki_pos);
/*
* If generic_perform_write() returned a synchronous error
* then we want to return the number of bytes which were
@ -2610,15 +2570,15 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
err = status;
goto out;
}
iocb->ki_pos = pos + status;
/*
* We need to ensure that the page cache pages are written to
* disk and invalidated to preserve the expected O_DIRECT
* semantics.
*/
endbyte = pos + status - 1;
err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
err = filemap_write_and_wait_range(mapping, pos, endbyte);
if (err == 0) {
iocb->ki_pos = endbyte + 1;
written += status;
invalidate_mapping_pages(mapping,
pos >> PAGE_CACHE_SHIFT,
@ -2630,9 +2590,9 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
*/
}
} else {
written = generic_perform_write(file, from, pos);
if (likely(written >= 0))
iocb->ki_pos = pos + written;
written = generic_perform_write(file, from, iocb->ki_pos);
if (likely(written > 0))
iocb->ki_pos += written;
}
out:
current->backing_dev_info = NULL;
@ -2656,7 +2616,9 @@ ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
ssize_t ret;
mutex_lock(&inode->i_mutex);
ret = __generic_file_write_iter(iocb, from);
ret = generic_write_checks(iocb, from);
if (ret > 0)
ret = __generic_file_write_iter(iocb, from);
mutex_unlock(&inode->i_mutex);
if (ret > 0) {

4
mm/page_io.c
View file

@ -277,9 +277,7 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
set_page_writeback(page);
unlock_page(page);
ret = mapping->a_ops->direct_IO(ITER_BVEC | WRITE,
&kiocb, &from,
kiocb.ki_pos);
ret = mapping->a_ops->direct_IO(&kiocb, &from, kiocb.ki_pos);
if (ret == PAGE_SIZE) {
count_vm_event(PSWPOUT);
ret = 0;