xfs: remove xfs_file_wait_for_io
[cascardo/linux.git] / fs / xfs / xfs_file.c
index 2bc58b3..9372975 100644 (file)
@@ -38,6 +38,7 @@
 #include "xfs_icache.h"
 #include "xfs_pnfs.h"
 #include "xfs_iomap.h"
+#include "xfs_reflink.h"
 
 #include <linux/dcache.h>
 #include <linux/falloc.h>
@@ -248,6 +249,7 @@ xfs_file_dio_aio_read(
        struct xfs_inode        *ip = XFS_I(inode);
        loff_t                  isize = i_size_read(inode);
        size_t                  count = iov_iter_count(to);
+       loff_t                  end = iocb->ki_pos + count - 1;
        struct iov_iter         data;
        struct xfs_buftarg      *target;
        ssize_t                 ret = 0;
@@ -271,49 +273,21 @@ xfs_file_dio_aio_read(
 
        file_accessed(iocb->ki_filp);
 
-       /*
-        * 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 (mapping->nrpages) {
-               xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
-               xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
+               ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end);
+               if (ret)
+                       goto out_unlock;
 
                /*
-                * 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.
+                * 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.
                 */
-               if (mapping->nrpages) {
-                       ret = filemap_write_and_wait(mapping);
-                       if (ret) {
-                               xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
-                               return ret;
-                       }
-
-                       /*
-                        * 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(mapping);
-                       WARN_ON_ONCE(ret);
-                       ret = 0;
-               }
-               xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
+               ret = invalidate_inode_pages2_range(mapping,
+                               iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
+               WARN_ON_ONCE(ret);
+               ret = 0;
        }
 
        data = *to;
@@ -323,8 +297,9 @@ xfs_file_dio_aio_read(
                iocb->ki_pos += ret;
                iov_iter_advance(to, ret);
        }
-       xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
 
+out_unlock:
+       xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
        return ret;
 }
 
@@ -569,61 +544,49 @@ xfs_file_dio_aio_write(
        if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
                return -EINVAL;
 
-       /* "unaligned" here means not aligned to a filesystem block */
-       if ((iocb->ki_pos & mp->m_blockmask) ||
-           ((iocb->ki_pos + count) & mp->m_blockmask))
-               unaligned_io = 1;
-
        /*
-        * We don't need to take an exclusive lock unless there page cache needs
-        * to be invalidated or unaligned IO is being executed. We don't need to
-        * consider the EOF extension case here because
-        * xfs_file_aio_write_checks() will relock the inode as necessary for
-        * EOF zeroing cases and fill out the new inode size as appropriate.
+        * Don't take the exclusive iolock here unless the I/O is unaligned to
+        * the file system block size.  We don't need to consider the EOF
+        * extension case here because xfs_file_aio_write_checks() will relock
+        * the inode as necessary for EOF zeroing cases and fill out the new
+        * inode size as appropriate.
         */
-       if (unaligned_io || mapping->nrpages)
+       if ((iocb->ki_pos & mp->m_blockmask) ||
+           ((iocb->ki_pos + count) & mp->m_blockmask)) {
+               unaligned_io = 1;
                iolock = XFS_IOLOCK_EXCL;
-       else
+       } else {
                iolock = XFS_IOLOCK_SHARED;
-       xfs_rw_ilock(ip, iolock);
-
-       /*
-        * Recheck if there are cached pages that need invalidate after we got
-        * the iolock to protect against other threads adding new pages while
-        * we were waiting for the iolock.
-        */
-       if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) {
-               xfs_rw_iunlock(ip, iolock);
-               iolock = XFS_IOLOCK_EXCL;
-               xfs_rw_ilock(ip, iolock);
        }
 
+       xfs_rw_ilock(ip, iolock);
+
        ret = xfs_file_aio_write_checks(iocb, from, &iolock);
        if (ret)
                goto out;
        count = iov_iter_count(from);
        end = iocb->ki_pos + count - 1;
 
-       /*
-        * See xfs_file_dio_aio_read() for why we do a full-file flush here.
-        */
        if (mapping->nrpages) {
-               ret = filemap_write_and_wait(VFS_I(ip)->i_mapping);
+               ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end);
                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.
                 */
-               ret = invalidate_inode_pages2(VFS_I(ip)->i_mapping);
+               ret = invalidate_inode_pages2_range(mapping,
+                               iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
                WARN_ON_ONCE(ret);
                ret = 0;
        }
 
        /*
         * If we are doing unaligned IO, wait for all other IO to drain,
-        * otherwise demote the lock if we had to flush cached pages
+        * otherwise demote the lock if we had to take the exclusive lock
+        * for other reasons in xfs_file_aio_write_checks.
         */
        if (unaligned_io)
                inode_dio_wait(inode);
@@ -634,6 +597,13 @@ xfs_file_dio_aio_write(
 
        trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
 
+       /* If this is a block-aligned directio CoW, remap immediately. */
+       if (xfs_is_reflink_inode(ip) && !unaligned_io) {
+               ret = xfs_reflink_allocate_cow_range(ip, iocb->ki_pos, count);
+               if (ret)
+                       goto out;
+       }
+
        data = *from;
        ret = __blockdev_direct_IO(iocb, inode, target->bt_bdev, &data,
                        xfs_get_blocks_direct, xfs_end_io_direct_write,
@@ -735,6 +705,9 @@ write_retry:
                enospc = xfs_inode_free_quota_eofblocks(ip);
                if (enospc)
                        goto write_retry;
+               enospc = xfs_inode_free_quota_cowblocks(ip);
+               if (enospc)
+                       goto write_retry;
        } else if (ret == -ENOSPC && !enospc) {
                struct xfs_eofblocks eofb = {0};
 
@@ -774,10 +747,20 @@ xfs_file_write_iter(
 
        if (IS_DAX(inode))
                ret = xfs_file_dax_write(iocb, from);
-       else if (iocb->ki_flags & IOCB_DIRECT)
+       else if (iocb->ki_flags & IOCB_DIRECT) {
+               /*
+                * Allow a directio write to fall back to a buffered
+                * write *only* in the case that we're doing a reflink
+                * CoW.  In all other directio scenarios we do not
+                * allow an operation to fall back to buffered mode.
+                */
                ret = xfs_file_dio_aio_write(iocb, from);
-       else
+               if (ret == -EREMCHG)
+                       goto buffered;
+       } else {
+buffered:
                ret = xfs_file_buffered_aio_write(iocb, from);
+       }
 
        if (ret > 0) {
                XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
@@ -791,7 +774,7 @@ xfs_file_write_iter(
 #define        XFS_FALLOC_FL_SUPPORTED                                         \
                (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |           \
                 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |      \
-                FALLOC_FL_INSERT_RANGE)
+                FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE)
 
 STATIC long
 xfs_file_fallocate(
@@ -881,9 +864,15 @@ xfs_file_fallocate(
 
                if (mode & FALLOC_FL_ZERO_RANGE)
                        error = xfs_zero_file_space(ip, offset, len);
-               else
+               else {
+                       if (mode & FALLOC_FL_UNSHARE_RANGE) {
+                               error = xfs_reflink_unshare(ip, offset, len);
+                               if (error)
+                                       goto out_unlock;
+                       }
                        error = xfs_alloc_file_space(ip, offset, len,
                                                     XFS_BMAPI_PREALLOC);
+               }
                if (error)
                        goto out_unlock;
        }
@@ -920,6 +909,187 @@ out_unlock:
        return error;
 }
 
+/* Hook up to the VFS reflink function */
+STATIC int
+xfs_file_share_range(
+       struct file     *file_in,
+       loff_t          pos_in,
+       struct file     *file_out,
+       loff_t          pos_out,
+       u64             len,
+       bool            is_dedupe)
+{
+       struct inode    *inode_in;
+       struct inode    *inode_out;
+       ssize_t         ret;
+       loff_t          bs;
+       loff_t          isize;
+       int             same_inode;
+       loff_t          blen;
+       unsigned int    flags = 0;
+
+       inode_in = file_inode(file_in);
+       inode_out = file_inode(file_out);
+       bs = inode_out->i_sb->s_blocksize;
+
+       /* Lock both files against IO */
+       same_inode = (inode_in == inode_out);
+       if (same_inode) {
+               xfs_ilock(XFS_I(inode_in), XFS_IOLOCK_EXCL);
+               xfs_ilock(XFS_I(inode_in), XFS_MMAPLOCK_EXCL);
+       } else {
+               xfs_lock_two_inodes(XFS_I(inode_in), XFS_I(inode_out),
+                               XFS_IOLOCK_EXCL);
+               xfs_lock_two_inodes(XFS_I(inode_in), XFS_I(inode_out),
+                               XFS_MMAPLOCK_EXCL);
+       }
+
+       /* Don't touch certain kinds of inodes */
+       ret = -EPERM;
+       if (IS_IMMUTABLE(inode_out))
+               goto out_unlock;
+       ret = -ETXTBSY;
+       if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
+               goto out_unlock;
+
+       /* Don't reflink dirs, pipes, sockets... */
+       ret = -EISDIR;
+       if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
+               goto out_unlock;
+       ret = -EINVAL;
+       if (S_ISFIFO(inode_in->i_mode) || S_ISFIFO(inode_out->i_mode))
+               goto out_unlock;
+       if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
+               goto out_unlock;
+
+       /* Don't share DAX file data for now. */
+       if (IS_DAX(inode_in) || IS_DAX(inode_out))
+               goto out_unlock;
+
+       /* Are we going all the way to the end? */
+       isize = i_size_read(inode_in);
+       if (isize == 0) {
+               ret = 0;
+               goto out_unlock;
+       }
+
+       if (len == 0)
+               len = isize - pos_in;
+
+       /* Ensure offsets don't wrap and the input is inside i_size */
+       if (pos_in + len < pos_in || pos_out + len < pos_out ||
+           pos_in + len > isize)
+               goto out_unlock;
+
+       /* Don't allow dedupe past EOF in the dest file */
+       if (is_dedupe) {
+               loff_t  disize;
+
+               disize = i_size_read(inode_out);
+               if (pos_out >= disize || pos_out + len > disize)
+                       goto out_unlock;
+       }
+
+       /* If we're linking to EOF, continue to the block boundary. */
+       if (pos_in + len == isize)
+               blen = ALIGN(isize, bs) - pos_in;
+       else
+               blen = len;
+
+       /* Only reflink if we're aligned to block boundaries */
+       if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) ||
+           !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs))
+               goto out_unlock;
+
+       /* Don't allow overlapped reflink within the same file */
+       if (same_inode && pos_out + blen > pos_in && pos_out < pos_in + blen)
+               goto out_unlock;
+
+       /* Wait for the completion of any pending IOs on both files */
+       inode_dio_wait(inode_in);
+       if (!same_inode)
+               inode_dio_wait(inode_out);
+
+       ret = filemap_write_and_wait_range(inode_in->i_mapping,
+                       pos_in, pos_in + len - 1);
+       if (ret)
+               goto out_unlock;
+
+       ret = filemap_write_and_wait_range(inode_out->i_mapping,
+                       pos_out, pos_out + len - 1);
+       if (ret)
+               goto out_unlock;
+
+       if (is_dedupe)
+               flags |= XFS_REFLINK_DEDUPE;
+       ret = xfs_reflink_remap_range(XFS_I(inode_in), pos_in, XFS_I(inode_out),
+                       pos_out, len, flags);
+
+out_unlock:
+       xfs_iunlock(XFS_I(inode_in), XFS_MMAPLOCK_EXCL);
+       xfs_iunlock(XFS_I(inode_in), XFS_IOLOCK_EXCL);
+       if (!same_inode) {
+               xfs_iunlock(XFS_I(inode_out), XFS_MMAPLOCK_EXCL);
+               xfs_iunlock(XFS_I(inode_out), XFS_IOLOCK_EXCL);
+       }
+       return ret;
+}
+
+STATIC ssize_t
+xfs_file_copy_range(
+       struct file     *file_in,
+       loff_t          pos_in,
+       struct file     *file_out,
+       loff_t          pos_out,
+       size_t          len,
+       unsigned int    flags)
+{
+       int             error;
+
+       error = xfs_file_share_range(file_in, pos_in, file_out, pos_out,
+                                    len, false);
+       if (error)
+               return error;
+       return len;
+}
+
+STATIC int
+xfs_file_clone_range(
+       struct file     *file_in,
+       loff_t          pos_in,
+       struct file     *file_out,
+       loff_t          pos_out,
+       u64             len)
+{
+       return xfs_file_share_range(file_in, pos_in, file_out, pos_out,
+                                    len, false);
+}
+
+#define XFS_MAX_DEDUPE_LEN     (16 * 1024 * 1024)
+STATIC ssize_t
+xfs_file_dedupe_range(
+       struct file     *src_file,
+       u64             loff,
+       u64             len,
+       struct file     *dst_file,
+       u64             dst_loff)
+{
+       int             error;
+
+       /*
+        * Limit the total length we will dedupe for each operation.
+        * This is intended to bound the total time spent in this
+        * ioctl to something sane.
+        */
+       if (len > XFS_MAX_DEDUPE_LEN)
+               len = XFS_MAX_DEDUPE_LEN;
+
+       error = xfs_file_share_range(src_file, loff, dst_file, dst_loff,
+                                    len, true);
+       if (error)
+               return error;
+       return len;
+}
 
 STATIC int
 xfs_file_open(
@@ -1581,6 +1751,9 @@ const struct file_operations xfs_file_operations = {
        .fsync          = xfs_file_fsync,
        .get_unmapped_area = thp_get_unmapped_area,
        .fallocate      = xfs_file_fallocate,
+       .copy_file_range = xfs_file_copy_range,
+       .clone_file_range = xfs_file_clone_range,
+       .dedupe_file_range = xfs_file_dedupe_range,
 };
 
 const struct file_operations xfs_dir_file_operations = {