#include <linux/dcache.h>
#include <linux/falloc.h>
#include <linux/pagevec.h>
+#include <linux/backing-dev.h>
static const struct vm_operations_struct xfs_file_vm_ops;
}
/*
- * xfs_iozero
+ * xfs_iozero clears the specified range supplied via the page cache (except in
+ * the DAX case). Writes through the page cache will allocate blocks over holes,
+ * though the callers usually map the holes first and avoid them. If a block is
+ * not completely zeroed, then it will be read from disk before being partially
+ * zeroed.
*
- * xfs_iozero clears the specified range of buffer supplied,
- * and marks all the affected blocks as valid and modified. If
- * an affected block is not allocated, it will be allocated. If
- * an affected block is not completely overwritten, and is not
- * valid before the operation, it will be read from disk before
- * being partially zeroed.
+ * In the DAX case, we can just directly write to the underlying pages. This
+ * will not allocate blocks, but will avoid holes and unwritten extents and so
+ * not do unnecessary work.
*/
int
xfs_iozero(
{
struct page *page;
struct address_space *mapping;
- int status;
+ int status = 0;
+
mapping = VFS_I(ip)->i_mapping;
do {
if (bytes > count)
bytes = count;
- status = pagecache_write_begin(NULL, mapping, pos, bytes,
- AOP_FLAG_UNINTERRUPTIBLE,
- &page, &fsdata);
- if (status)
- break;
+ if (IS_DAX(VFS_I(ip))) {
+ status = dax_zero_page_range(VFS_I(ip), pos, bytes,
+ xfs_get_blocks_direct);
+ if (status)
+ break;
+ } else {
+ status = pagecache_write_begin(NULL, mapping, pos, bytes,
+ AOP_FLAG_UNINTERRUPTIBLE,
+ &page, &fsdata);
+ if (status)
+ break;
- zero_user(page, offset, bytes);
+ zero_user(page, offset, bytes);
- status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
- page, fsdata);
- WARN_ON(status <= 0); /* can't return less than zero! */
+ status = pagecache_write_end(NULL, mapping, pos, bytes,
+ bytes, page, fsdata);
+ WARN_ON(status <= 0); /* can't return less than zero! */
+ status = 0;
+ }
pos += bytes;
count -= bytes;
- status = 0;
} while (count);
return status;
tp = xfs_trans_alloc(ip->i_mount, XFS_TRANS_WRITEID);
error = xfs_trans_reserve(tp, &M_RES(ip->i_mount)->tr_writeid, 0, 0);
if (error) {
- xfs_trans_cancel(tp, 0);
+ xfs_trans_cancel(tp);
return error;
}
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
if (flags & XFS_PREALLOC_SYNC)
xfs_trans_set_sync(tp);
- return xfs_trans_commit(tp, 0);
+ return xfs_trans_commit(tp);
}
/*
}
/*
- * All metadata updates are logged, which means that we just have
- * to flush the log up to the latest LSN that touched the inode.
+ * All metadata updates are logged, which means that we just have to
+ * flush the log up to the latest LSN that touched the inode. If we have
+ * concurrent fsync/fdatasync() calls, we need them to all block on the
+ * log force before we clear the ili_fsync_fields field. This ensures
+ * that we don't get a racing sync operation that does not wait for the
+ * metadata to hit the journal before returning. If we race with
+ * clearing the ili_fsync_fields, then all that will happen is the log
+ * force will do nothing as the lsn will already be on disk. We can't
+ * race with setting ili_fsync_fields because that is done under
+ * XFS_ILOCK_EXCL, and that can't happen because we hold the lock shared
+ * until after the ili_fsync_fields is cleared.
*/
xfs_ilock(ip, XFS_ILOCK_SHARED);
if (xfs_ipincount(ip)) {
if (!datasync ||
- (ip->i_itemp->ili_fields & ~XFS_ILOG_TIMESTAMP))
+ (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
lsn = ip->i_itemp->ili_last_lsn;
}
- xfs_iunlock(ip, XFS_ILOCK_SHARED);
- if (lsn)
+ if (lsn) {
error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
+ ip->i_itemp->ili_fsync_fields = 0;
+ }
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
/*
* If we only have a single device, and the log force about was
xfs_fsize_t n;
loff_t pos = iocb->ki_pos;
- XFS_STATS_INC(xs_read_calls);
+ XFS_STATS_INC(mp, xs_read_calls);
if (unlikely(iocb->ki_flags & IOCB_DIRECT))
ioflags |= XFS_IO_ISDIRECT;
if (file->f_mode & FMODE_NOCMTIME)
ioflags |= XFS_IO_INVIS;
- if (unlikely(ioflags & XFS_IO_ISDIRECT)) {
+ if ((ioflags & XFS_IO_ISDIRECT) && !IS_DAX(inode)) {
xfs_buftarg_t *target =
XFS_IS_REALTIME_INODE(ip) ?
mp->m_rtdev_targp : mp->m_ddev_targp;
return -EIO;
/*
- * Locking is a bit tricky here. If we take an exclusive lock
- * for direct IO, we effectively serialise all new concurrent
- * read IO to this file and block it behind IO that is currently in
- * progress because IO in progress holds the IO lock shared. We only
- * need to hold the lock exclusive to blow away the page cache, so
- * only take lock exclusively if the page cache needs invalidation.
- * This allows the normal direct IO case of no page cache pages to
- * proceeed concurrently without serialisation.
+ * Locking is a bit tricky here. If we take an exclusive lock for direct
+ * IO, we effectively serialise all new concurrent read IO to this file
+ * and block it behind IO that is currently in progress because IO in
+ * progress holds the IO lock shared. We only need to hold the lock
+ * exclusive to blow away the page cache, so only take lock exclusively
+ * if the page cache needs invalidation. This allows the normal direct
+ * IO case of no page cache pages to proceeed concurrently without
+ * serialisation.
*/
xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
if ((ioflags & XFS_IO_ISDIRECT) && inode->i_mapping->nrpages) {
xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
+ /*
+ * The generic dio code only flushes the range of the particular
+ * I/O. Because we take an exclusive lock here, this whole
+ * sequence is considerably more expensive for us. This has a
+ * noticeable performance impact for any file with cached pages,
+ * even when outside of the range of the particular I/O.
+ *
+ * Hence, amortize the cost of the lock against a full file
+ * flush and reduce the chances of repeated iolock cycles going
+ * forward.
+ */
if (inode->i_mapping->nrpages) {
- ret = filemap_write_and_wait_range(
- VFS_I(ip)->i_mapping,
- pos, pos + size - 1);
+ ret = filemap_write_and_wait(VFS_I(ip)->i_mapping);
if (ret) {
xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
return ret;
* we fail to invalidate a page, but this should never
* happen on XFS. Warn if it does fail.
*/
- ret = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
- pos >> PAGE_CACHE_SHIFT,
- (pos + size - 1) >> PAGE_CACHE_SHIFT);
+ ret = invalidate_inode_pages2(VFS_I(ip)->i_mapping);
WARN_ON_ONCE(ret);
ret = 0;
}
ret = generic_file_read_iter(iocb, to);
if (ret > 0)
- XFS_STATS_ADD(xs_read_bytes, ret);
+ XFS_STATS_ADD(mp, xs_read_bytes, ret);
xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
return ret;
int ioflags = 0;
ssize_t ret;
- XFS_STATS_INC(xs_read_calls);
+ XFS_STATS_INC(ip->i_mount, xs_read_calls);
if (infilp->f_mode & FMODE_NOCMTIME)
ioflags |= XFS_IO_INVIS;
trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
- ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
+ /* for dax, we need to avoid the page cache */
+ if (IS_DAX(VFS_I(ip)))
+ ret = default_file_splice_read(infilp, ppos, pipe, count, flags);
+ else
+ ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
if (ret > 0)
- XFS_STATS_ADD(xs_read_bytes, ret);
+ XFS_STATS_ADD(ip->i_mount, xs_read_bytes, ret);
xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
return ret;
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
ASSERT(offset > isize);
+ trace_xfs_zero_eof(ip, isize, offset - isize);
+
/*
* First handle zeroing the block on which isize resides.
*
struct xfs_inode *ip = XFS_I(inode);
ssize_t error = 0;
size_t count = iov_iter_count(from);
+ bool drained_dio = false;
restart:
error = generic_write_checks(iocb, from);
if (error)
return error;
+ /* For changing security info in file_remove_privs() we need i_mutex */
+ if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
+ xfs_rw_iunlock(ip, *iolock);
+ *iolock = XFS_IOLOCK_EXCL;
+ xfs_rw_ilock(ip, *iolock);
+ goto restart;
+ }
/*
* If the offset is beyond the size of the file, we need to zero any
* blocks that fall between the existing EOF and the start of this
bool zero = false;
spin_unlock(&ip->i_flags_lock);
- if (*iolock == XFS_IOLOCK_SHARED) {
- xfs_rw_iunlock(ip, *iolock);
- *iolock = XFS_IOLOCK_EXCL;
- xfs_rw_ilock(ip, *iolock);
- iov_iter_reexpand(from, count);
-
+ if (!drained_dio) {
+ if (*iolock == XFS_IOLOCK_SHARED) {
+ xfs_rw_iunlock(ip, *iolock);
+ *iolock = XFS_IOLOCK_EXCL;
+ xfs_rw_ilock(ip, *iolock);
+ iov_iter_reexpand(from, count);
+ }
/*
* We now have an IO submission barrier in place, but
* AIO can do EOF updates during IO completion and hence
* no-op.
*/
inode_dio_wait(inode);
+ drained_dio = true;
goto restart;
}
error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), &zero);
* setgid bits if the process is not being run by root. This keeps
* people from modifying setuid and setgid binaries.
*/
- return file_remove_suid(file);
+ if (!IS_NOSEC(inode))
+ return file_remove_privs(file);
+ return 0;
}
/*
mp->m_rtdev_targp : mp->m_ddev_targp;
/* DIO must be aligned to device logical sector size */
- if ((pos | count) & target->bt_logical_sectormask)
+ if (!IS_DAX(inode) && ((pos | count) & target->bt_logical_sectormask))
return -EINVAL;
/* "unaligned" here means not aligned to a filesystem block */
pos = iocb->ki_pos;
end = pos + count - 1;
+ /*
+ * See xfs_file_read_iter() for why we do a full-file flush here.
+ */
if (mapping->nrpages) {
- ret = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
- pos, end);
+ ret = filemap_write_and_wait(VFS_I(ip)->i_mapping);
if (ret)
goto out;
/*
- * Invalidate whole pages. This can return an error if
- * we fail to invalidate a page, but this should never
- * happen on XFS. Warn if it does fail.
+ * Invalidate whole pages. This can return an error if we fail
+ * to invalidate a page, but this should never happen on XFS.
+ * Warn if it does fail.
*/
- ret = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
- pos >> PAGE_CACHE_SHIFT,
- end >> PAGE_CACHE_SHIFT);
+ ret = invalidate_inode_pages2(VFS_I(ip)->i_mapping);
WARN_ON_ONCE(ret);
ret = 0;
}
out:
xfs_rw_iunlock(ip, iolock);
- /* No fallback to buffered IO on errors for XFS. */
- ASSERT(ret < 0 || ret == count);
+ /*
+ * No fallback to buffered IO on errors for XFS. DAX can result in
+ * partial writes, but direct IO will either complete fully or fail.
+ */
+ ASSERT(ret < 0 || ret == count || IS_DAX(VFS_I(ip)));
return ret;
}
ssize_t ret;
size_t ocount = iov_iter_count(from);
- XFS_STATS_INC(xs_write_calls);
+ XFS_STATS_INC(ip->i_mount, xs_write_calls);
if (ocount == 0)
return 0;
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
return -EIO;
- if (unlikely(iocb->ki_flags & IOCB_DIRECT))
+ if ((iocb->ki_flags & IOCB_DIRECT) || IS_DAX(inode))
ret = xfs_file_dio_aio_write(iocb, from);
else
ret = xfs_file_buffered_aio_write(iocb, from);
if (ret > 0) {
ssize_t err;
- XFS_STATS_ADD(xs_write_bytes, ret);
+ XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
/* Handle various SYNC-type writes */
err = generic_write_sync(file, iocb->ki_pos - ret, ret);
return xfs_readdir(ip, ctx, bufsize);
}
-STATIC int
-xfs_file_mmap(
- struct file *filp,
- struct vm_area_struct *vma)
-{
- vma->vm_ops = &xfs_file_vm_ops;
-
- file_accessed(filp);
- return 0;
-}
-
/*
* This type is designed to indicate the type of offset we would like
* to search from page cache for xfs_seek_hole_data().
* ordering of:
*
* mmap_sem (MM)
- * i_mmap_lock (XFS - truncate serialisation)
- * page_lock (MM)
- * i_lock (XFS - extent map serialisation)
+ * sb_start_pagefault(vfs, freeze)
+ * i_mmaplock (XFS - truncate serialisation)
+ * page_lock (MM)
+ * i_lock (XFS - extent map serialisation)
+ */
+
+/*
+ * mmap()d file has taken write protection fault and is being made writable. We
+ * can set the page state up correctly for a writable page, which means we can
+ * do correct delalloc accounting (ENOSPC checking!) and unwritten extent
+ * mapping.
*/
+STATIC int
+xfs_filemap_page_mkwrite(
+ struct vm_area_struct *vma,
+ struct vm_fault *vmf)
+{
+ struct inode *inode = file_inode(vma->vm_file);
+ int ret;
+
+ trace_xfs_filemap_page_mkwrite(XFS_I(inode));
+
+ sb_start_pagefault(inode->i_sb);
+ file_update_time(vma->vm_file);
+ xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+
+ if (IS_DAX(inode)) {
+ ret = __dax_mkwrite(vma, vmf, xfs_get_blocks_dax_fault, NULL);
+ } else {
+ ret = block_page_mkwrite(vma, vmf, xfs_get_blocks);
+ ret = block_page_mkwrite_return(ret);
+ }
+
+ xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+ sb_end_pagefault(inode->i_sb);
+
+ return ret;
+}
+
STATIC int
xfs_filemap_fault(
struct vm_area_struct *vma,
struct vm_fault *vmf)
{
- struct xfs_inode *ip = XFS_I(vma->vm_file->f_mapping->host);
- int error;
+ struct inode *inode = file_inode(vma->vm_file);
+ int ret;
- trace_xfs_filemap_fault(ip);
+ trace_xfs_filemap_fault(XFS_I(inode));
- xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
- error = filemap_fault(vma, vmf);
- xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+ /* DAX can shortcut the normal fault path on write faults! */
+ if ((vmf->flags & FAULT_FLAG_WRITE) && IS_DAX(inode))
+ return xfs_filemap_page_mkwrite(vma, vmf);
- return error;
+ xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+ if (IS_DAX(inode)) {
+ /*
+ * we do not want to trigger unwritten extent conversion on read
+ * faults - that is unnecessary overhead and would also require
+ * changes to xfs_get_blocks_direct() to map unwritten extent
+ * ioend for conversion on read-only mappings.
+ */
+ ret = __dax_fault(vma, vmf, xfs_get_blocks_dax_fault, NULL);
+ } else
+ ret = filemap_fault(vma, vmf);
+ xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+
+ return ret;
}
/*
- * mmap()d file has taken write protection fault and is being made writable. We
- * can set the page state up correctly for a writable page, which means we can
- * do correct delalloc accounting (ENOSPC checking!) and unwritten extent
- * mapping.
+ * Similar to xfs_filemap_fault(), the DAX fault path can call into here on
+ * both read and write faults. Hence we need to handle both cases. There is no
+ * ->pmd_mkwrite callout for huge pages, so we have a single function here to
+ * handle both cases here. @flags carries the information on the type of fault
+ * occuring.
*/
STATIC int
-xfs_filemap_page_mkwrite(
+xfs_filemap_pmd_fault(
+ struct vm_area_struct *vma,
+ unsigned long addr,
+ pmd_t *pmd,
+ unsigned int flags)
+{
+ struct inode *inode = file_inode(vma->vm_file);
+ struct xfs_inode *ip = XFS_I(inode);
+ int ret;
+
+ if (!IS_DAX(inode))
+ return VM_FAULT_FALLBACK;
+
+ trace_xfs_filemap_pmd_fault(ip);
+
+ if (flags & FAULT_FLAG_WRITE) {
+ sb_start_pagefault(inode->i_sb);
+ file_update_time(vma->vm_file);
+ }
+
+ xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+ ret = __dax_pmd_fault(vma, addr, pmd, flags, xfs_get_blocks_dax_fault,
+ NULL);
+ xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
+
+ if (flags & FAULT_FLAG_WRITE)
+ sb_end_pagefault(inode->i_sb);
+
+ return ret;
+}
+
+/*
+ * pfn_mkwrite was originally inteneded to ensure we capture time stamp
+ * updates on write faults. In reality, it's need to serialise against
+ * truncate similar to page_mkwrite. Hence we open-code dax_pfn_mkwrite()
+ * here and cycle the XFS_MMAPLOCK_SHARED to ensure we serialise the fault
+ * barrier in place.
+ */
+static int
+xfs_filemap_pfn_mkwrite(
struct vm_area_struct *vma,
struct vm_fault *vmf)
{
- struct xfs_inode *ip = XFS_I(vma->vm_file->f_mapping->host);
- int error;
- trace_xfs_filemap_page_mkwrite(ip);
+ struct inode *inode = file_inode(vma->vm_file);
+ struct xfs_inode *ip = XFS_I(inode);
+ int ret = VM_FAULT_NOPAGE;
+ loff_t size;
+
+ trace_xfs_filemap_pfn_mkwrite(ip);
+
+ sb_start_pagefault(inode->i_sb);
+ file_update_time(vma->vm_file);
+ /* check if the faulting page hasn't raced with truncate */
xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
- error = block_page_mkwrite(vma, vmf, xfs_get_blocks);
+ size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ if (vmf->pgoff >= size)
+ ret = VM_FAULT_SIGBUS;
xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+ sb_end_pagefault(inode->i_sb);
+ return ret;
- return error;
+}
+
+static const struct vm_operations_struct xfs_file_vm_ops = {
+ .fault = xfs_filemap_fault,
+ .pmd_fault = xfs_filemap_pmd_fault,
+ .map_pages = filemap_map_pages,
+ .page_mkwrite = xfs_filemap_page_mkwrite,
+ .pfn_mkwrite = xfs_filemap_pfn_mkwrite,
+};
+
+STATIC int
+xfs_file_mmap(
+ struct file *filp,
+ struct vm_area_struct *vma)
+{
+ file_accessed(filp);
+ vma->vm_ops = &xfs_file_vm_ops;
+ if (IS_DAX(file_inode(filp)))
+ vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
+ return 0;
}
const struct file_operations xfs_file_operations = {
#endif
.fsync = xfs_dir_fsync,
};
-
-static const struct vm_operations_struct xfs_file_vm_ops = {
- .fault = xfs_filemap_fault,
- .map_pages = filemap_map_pages,
- .page_mkwrite = xfs_filemap_page_mkwrite,
-};
Code Review / kvmfornfv.git / blobdiff