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Message-Id: <20170531124540.8782-12-jlayton@redhat.com>
Date: Wed, 31 May 2017 08:45:34 -0400
From: Jeff Layton <jlayton@...hat.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
Al Viro <viro@...IV.linux.org.uk>, Jan Kara <jack@...e.cz>,
tytso@....edu, axboe@...nel.dk, mawilcox@...rosoft.com,
ross.zwisler@...ux.intel.com, corbet@....net
Cc: linux-ext4@...r.kernel.org, linux-fsdevel@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-block@...r.kernel.org,
linux-doc@...r.kernel.org
Subject: [PATCH v5 11/17] fs: add f_md_wb_err field to struct file for tracking metadata errors
Some filesystems (particularly local ones) keep a different mapping for
metadata writeback. Add a second errseq_t to struct file for tracking
metadata writeback errors. Also add a new function for checking a
mapping of the caller's choosing vs. the f_md_wb_err value.
Signed-off-by: Jeff Layton <jlayton@...hat.com>
---
include/linux/fs.h | 3 +++
include/trace/events/filemap.h | 23 ++++++++++-------------
mm/filemap.c | 40 +++++++++++++++++++++++++++++++---------
3 files changed, 44 insertions(+), 22 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f483c23866c4..df1d68e3605a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -871,6 +871,7 @@ struct file {
struct list_head f_tfile_llink;
#endif /* #ifdef CONFIG_EPOLL */
struct address_space *f_mapping;
+ errseq_t f_md_wb_err; /* optional metadata wb error tracking */
} __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */
struct file_handle {
@@ -2549,6 +2550,8 @@ extern int filemap_fdatawrite_range(struct address_space *mapping,
extern int filemap_check_errors(struct address_space *mapping);
extern int __must_check filemap_report_wb_err(struct file *file);
+extern int __must_check filemap_report_md_wb_err(struct file *file,
+ struct address_space *mapping);
extern void __filemap_set_wb_err(struct address_space *mapping, int err);
/**
diff --git a/include/trace/events/filemap.h b/include/trace/events/filemap.h
index 2af66920f267..6e0d78c01a2e 100644
--- a/include/trace/events/filemap.h
+++ b/include/trace/events/filemap.h
@@ -79,12 +79,11 @@ TRACE_EVENT(filemap_set_wb_err,
);
TRACE_EVENT(filemap_report_wb_err,
- TP_PROTO(struct file *file, errseq_t old),
+ TP_PROTO(struct address_space *mapping, errseq_t old, errseq_t new),
- TP_ARGS(file, old),
+ TP_ARGS(mapping, old, new),
TP_STRUCT__entry(
- __field(struct file *, file);
__field(unsigned long, i_ino)
__field(dev_t, s_dev)
__field(errseq_t, old)
@@ -92,20 +91,18 @@ TRACE_EVENT(filemap_report_wb_err,
),
TP_fast_assign(
- __entry->file = file;
- __entry->i_ino = file->f_mapping->host->i_ino;
- if (file->f_mapping->host->i_sb)
- __entry->s_dev = file->f_mapping->host->i_sb->s_dev;
+ __entry->i_ino = mapping->host->i_ino;
+ if (mapping->host->i_sb)
+ __entry->s_dev = mapping->host->i_sb->s_dev;
else
- __entry->s_dev = file->f_mapping->host->i_rdev;
+ __entry->s_dev = mapping->host->i_rdev;
__entry->old = old;
- __entry->new = file->f_wb_err;
+ __entry->new = new;
),
- TP_printk("file=%p dev=%d:%d ino=0x%lx old=0x%x new=0x%x",
- __entry->file, MAJOR(__entry->s_dev),
- MINOR(__entry->s_dev), __entry->i_ino, __entry->old,
- __entry->new)
+ TP_printk("dev=%d:%d ino=0x%lx old=0x%x new=0x%x",
+ MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+ __entry->i_ino, __entry->old, __entry->new)
);
#endif /* _TRACE_FILEMAP_H */
diff --git a/mm/filemap.c b/mm/filemap.c
index 38a14dc825ad..0edf0234973e 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -631,21 +631,20 @@ EXPORT_SYMBOL(__filemap_set_wb_err);
* value is protected by the f_lock since we must ensure that it reflects
* the latest value swapped in for this file descriptor.
*/
-int filemap_report_wb_err(struct file *file)
+static int __filemap_report_wb_err(errseq_t *cursor, spinlock_t *lock,
+ struct address_space *mapping)
{
int err = 0;
- errseq_t old = READ_ONCE(file->f_wb_err);
- struct address_space *mapping = file->f_mapping;
+ errseq_t old = READ_ONCE(*cursor);
/* Locklessly handle the common case where nothing has changed */
if (errseq_check(&mapping->wb_err, old)) {
/* Something changed, must use slow path */
- spin_lock(&file->f_lock);
- old = file->f_wb_err;
- err = errseq_check_and_advance(&mapping->wb_err,
- &file->f_wb_err);
- trace_filemap_report_wb_err(file, old);
- spin_unlock(&file->f_lock);
+ spin_lock(lock);
+ old = *cursor;
+ err = errseq_check_and_advance(&mapping->wb_err, cursor);
+ trace_filemap_report_wb_err(mapping, old, *cursor);
+ spin_unlock(lock);
}
/* Now clear the AS_* flags if any are set */
@@ -656,9 +655,32 @@ int filemap_report_wb_err(struct file *file)
return err;
}
+EXPORT_SYMBOL(__filemap_report_wb_err);
+
+int filemap_report_wb_err(struct file *file)
+{
+ return __filemap_report_wb_err(&file->f_wb_err, &file->f_lock,
+ file->f_mapping);
+}
EXPORT_SYMBOL(filemap_report_wb_err);
/**
+ * filemap_report_md_wb_err - report wb error (if any) that was previously set
+ * @file: struct file on which the error is being reported
+ * @mapping: pointer to metadata mapping to check
+ *
+ * Many filesystems keep inode metadata in the pagecache, and will use the
+ * cache to write it back to the backing store. This function is for these
+ * callers to track metadata writeback.
+ */
+int filemap_report_md_wb_err(struct file *file, struct address_space *mapping)
+{
+ return __filemap_report_wb_err(&file->f_md_wb_err, &file->f_lock,
+ mapping);
+}
+EXPORT_SYMBOL(filemap_report_md_wb_err);
+
+/**
* replace_page_cache_page - replace a pagecache page with a new one
* @old: page to be replaced
* @new: page to replace with
--
2.9.4
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