Merge tag 'vfs-6.10.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

[sfrench/cifs-2.6.git] / mm / filemap.c

diff --git a/mm/filemap.c b/mm/filemap.c
index 30de18c4fd28a907184695e3cf0f60079e956d89..1d6b3a3690777b058251035609976bfd4d3299f5 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1540,7 +1540,7 @@ EXPORT_SYMBOL(folio_end_private_2);
  * folio_wait_private_2 - Wait for PG_private_2 to be cleared on a folio.
  * @folio: The folio to wait on.
  *
- * Wait for PG_private_2 (aka PG_fscache) to be cleared on a folio.
+ * Wait for PG_private_2 to be cleared on a folio.
  */
 void folio_wait_private_2(struct folio *folio)
 {
@@ -1553,8 +1553,8 @@ EXPORT_SYMBOL(folio_wait_private_2);
  * folio_wait_private_2_killable - Wait for PG_private_2 to be cleared on a folio.
  * @folio: The folio to wait on.
  *
- * Wait for PG_private_2 (aka PG_fscache) to be cleared on a folio or until a
- * fatal signal is received by the calling task.
+ * Wait for PG_private_2 to be cleared on a folio or until a fatal signal is
+ * received by the calling task.
  *
  * Return:
  * - 0 if successful.
@@ -4134,6 +4134,60 @@ bool filemap_release_folio(struct folio *folio, gfp_t gfp)
 }
 EXPORT_SYMBOL(filemap_release_folio);
 
+/**
+ * filemap_invalidate_inode - Invalidate/forcibly write back a range of an inode's pagecache
+ * @inode: The inode to flush
+ * @flush: Set to write back rather than simply invalidate.
+ * @start: First byte to in range.
+ * @end: Last byte in range (inclusive), or LLONG_MAX for everything from start
+ *       onwards.
+ *
+ * Invalidate all the folios on an inode that contribute to the specified
+ * range, possibly writing them back first.  Whilst the operation is
+ * undertaken, the invalidate lock is held to prevent new folios from being
+ * installed.
+ */
+int filemap_invalidate_inode(struct inode *inode, bool flush,
+                            loff_t start, loff_t end)
+{
+       struct address_space *mapping = inode->i_mapping;
+       pgoff_t first = start >> PAGE_SHIFT;
+       pgoff_t last = end >> PAGE_SHIFT;
+       pgoff_t nr = end == LLONG_MAX ? ULONG_MAX : last - first + 1;
+
+       if (!mapping || !mapping->nrpages || end < start)
+               goto out;
+
+       /* Prevent new folios from being added to the inode. */
+       filemap_invalidate_lock(mapping);
+
+       if (!mapping->nrpages)
+               goto unlock;
+
+       unmap_mapping_pages(mapping, first, nr, false);
+
+       /* Write back the data if we're asked to. */
+       if (flush) {
+               struct writeback_control wbc = {
+                       .sync_mode      = WB_SYNC_ALL,
+                       .nr_to_write    = LONG_MAX,
+                       .range_start    = start,
+                       .range_end      = end,
+               };
+
+               filemap_fdatawrite_wbc(mapping, &wbc);
+       }
+
+       /* Wait for writeback to complete on all folios and discard. */
+       truncate_inode_pages_range(mapping, start, end);
+
+unlock:
+       filemap_invalidate_unlock(mapping);
+out:
+       return filemap_check_errors(mapping);
+}
+EXPORT_SYMBOL_GPL(filemap_invalidate_inode);
+
 #ifdef CONFIG_CACHESTAT_SYSCALL
 /**
  * filemap_cachestat() - compute the page cache statistics of a mapping