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| author | Ross Zwisler <ross.zwisler@linux.intel.com> | 2018-07-29 16:59:16 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2018-07-29 16:59:16 -0400 |
| commit | cdbf8897cb09b7baf2b8a7e78051a35a872b01d5 (patch) | |
| tree | 948dc77af5c5b9627fbe8b6fd3eb56e48556f1ef /fs/dax.c | |
| parent | 0694f8c39f113bcdb759a7f84981a69bf5d7161d (diff) | |
| download | lwn-cdbf8897cb09b7baf2b8a7e78051a35a872b01d5.tar.gz lwn-cdbf8897cb09b7baf2b8a7e78051a35a872b01d5.zip | |
dax: dax_layout_busy_page() warn on !exceptional
Inodes using DAX should only ever have exceptional entries in their page
caches. Make this clear by warning if the iteration in
dax_layout_busy_page() ever sees a non-exceptional entry, and by adding a
comment for the pagevec_release() call which only deals with struct page
pointers.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/dax.c')
| -rw-r--r-- | fs/dax.c | 10 |
1 files changed, 9 insertions, 1 deletions
@@ -566,7 +566,8 @@ struct page *dax_layout_busy_page(struct address_space *mapping) if (index >= end) break; - if (!radix_tree_exceptional_entry(pvec_ent)) + if (WARN_ON_ONCE( + !radix_tree_exceptional_entry(pvec_ent))) continue; xa_lock_irq(&mapping->i_pages); @@ -578,6 +579,13 @@ struct page *dax_layout_busy_page(struct address_space *mapping) if (page) break; } + + /* + * We don't expect normal struct page entries to exist in our + * tree, but we keep these pagevec calls so that this code is + * consistent with the common pattern for handling pagevecs + * throughout the kernel. + */ pagevec_remove_exceptionals(&pvec); pagevec_release(&pvec); index++; |