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-rw-r--r--include/linux/buffer_head.h1
-rw-r--r--include/linux/errseq.h19
-rw-r--r--include/linux/fs.h61
-rw-r--r--include/linux/pagemap.h31
4 files changed, 105 insertions, 7 deletions
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index bd029e52ef5e..e0abeba3ced7 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -149,6 +149,7 @@ void buffer_check_dirty_writeback(struct page *page,
*/
void mark_buffer_dirty(struct buffer_head *bh);
+void mark_buffer_write_io_error(struct buffer_head *bh);
void init_buffer(struct buffer_head *, bh_end_io_t *, void *);
void touch_buffer(struct buffer_head *bh);
void set_bh_page(struct buffer_head *bh,
diff --git a/include/linux/errseq.h b/include/linux/errseq.h
new file mode 100644
index 000000000000..9e0d444ac88d
--- /dev/null
+++ b/include/linux/errseq.h
@@ -0,0 +1,19 @@
+#ifndef _LINUX_ERRSEQ_H
+#define _LINUX_ERRSEQ_H
+
+/* See lib/errseq.c for more info */
+
+typedef u32 errseq_t;
+
+errseq_t __errseq_set(errseq_t *eseq, int err);
+static inline void errseq_set(errseq_t *eseq, int err)
+{
+ /* Optimize for the common case of no error */
+ if (unlikely(err))
+ __errseq_set(eseq, err);
+}
+
+errseq_t errseq_sample(errseq_t *eseq);
+int errseq_check(errseq_t *eseq, errseq_t since);
+int errseq_check_and_advance(errseq_t *eseq, errseq_t *since);
+#endif
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 978fb5966a25..0cfa47125d52 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -32,6 +32,7 @@
#include <linux/workqueue.h>
#include <linux/delayed_call.h>
#include <linux/uuid.h>
+#include <linux/errseq.h>
#include <asm/byteorder.h>
#include <uapi/linux/fs.h>
@@ -401,6 +402,7 @@ struct address_space {
gfp_t gfp_mask; /* implicit gfp mask for allocations */
struct list_head private_list; /* ditto */
void *private_data; /* ditto */
+ errseq_t wb_err;
} __attribute__((aligned(sizeof(long))));
/*
* On most architectures that alignment is already the case; but
@@ -879,6 +881,7 @@ struct file {
struct list_head f_tfile_llink;
#endif /* #ifdef CONFIG_EPOLL */
struct address_space *f_mapping;
+ errseq_t f_wb_err;
} __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */
struct file_handle {
@@ -2536,7 +2539,7 @@ extern int write_inode_now(struct inode *, int);
extern int filemap_fdatawrite(struct address_space *);
extern int filemap_flush(struct address_space *);
extern int filemap_fdatawait(struct address_space *);
-extern void filemap_fdatawait_keep_errors(struct address_space *);
+extern int filemap_fdatawait_keep_errors(struct address_space *mapping);
extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
loff_t lend);
extern bool filemap_range_has_page(struct address_space *, loff_t lstart,
@@ -2550,6 +2553,62 @@ extern int filemap_fdatawrite_range(struct address_space *mapping,
loff_t start, loff_t end);
extern int filemap_check_errors(struct address_space *mapping);
+extern void __filemap_set_wb_err(struct address_space *mapping, int err);
+extern int __must_check file_check_and_advance_wb_err(struct file *file);
+extern int __must_check file_write_and_wait_range(struct file *file,
+ loff_t start, loff_t end);
+
+/**
+ * filemap_set_wb_err - set a writeback error on an address_space
+ * @mapping: mapping in which to set writeback error
+ * @err: error to be set in mapping
+ *
+ * When writeback fails in some way, we must record that error so that
+ * userspace can be informed when fsync and the like are called. We endeavor
+ * to report errors on any file that was open at the time of the error. Some
+ * internal callers also need to know when writeback errors have occurred.
+ *
+ * When a writeback error occurs, most filesystems will want to call
+ * filemap_set_wb_err to record the error in the mapping so that it will be
+ * automatically reported whenever fsync is called on the file.
+ *
+ * FIXME: mention FS_* flag here?
+ */
+static inline void filemap_set_wb_err(struct address_space *mapping, int err)
+{
+ /* Fastpath for common case of no error */
+ if (unlikely(err))
+ __filemap_set_wb_err(mapping, err);
+}
+
+/**
+ * filemap_check_wb_error - has an error occurred since the mark was sampled?
+ * @mapping: mapping to check for writeback errors
+ * @since: previously-sampled errseq_t
+ *
+ * Grab the errseq_t value from the mapping, and see if it has changed "since"
+ * the given value was sampled.
+ *
+ * If it has then report the latest error set, otherwise return 0.
+ */
+static inline int filemap_check_wb_err(struct address_space *mapping,
+ errseq_t since)
+{
+ return errseq_check(&mapping->wb_err, since);
+}
+
+/**
+ * filemap_sample_wb_err - sample the current errseq_t to test for later errors
+ * @mapping: mapping to be sampled
+ *
+ * Writeback errors are always reported relative to a particular sample point
+ * in the past. This function provides those sample points.
+ */
+static inline errseq_t filemap_sample_wb_err(struct address_space *mapping)
+{
+ return errseq_sample(&mapping->wb_err);
+}
+
extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
int datasync);
extern int vfs_fsync(struct file *file, int datasync);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index e7bbd9d4dc6c..baa9344dcd10 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -28,14 +28,33 @@ enum mapping_flags {
AS_NO_WRITEBACK_TAGS = 5,
};
+/**
+ * mapping_set_error - record a writeback error in the address_space
+ * @mapping - the mapping in which an error should be set
+ * @error - the error to set in the mapping
+ *
+ * When writeback fails in some way, we must record that error so that
+ * userspace can be informed when fsync and the like are called. We endeavor
+ * to report errors on any file that was open at the time of the error. Some
+ * internal callers also need to know when writeback errors have occurred.
+ *
+ * When a writeback error occurs, most filesystems will want to call
+ * mapping_set_error to record the error in the mapping so that it can be
+ * reported when the application calls fsync(2).
+ */
static inline void mapping_set_error(struct address_space *mapping, int error)
{
- if (unlikely(error)) {
- if (error == -ENOSPC)
- set_bit(AS_ENOSPC, &mapping->flags);
- else
- set_bit(AS_EIO, &mapping->flags);
- }
+ if (likely(!error))
+ return;
+
+ /* Record in wb_err for checkers using errseq_t based tracking */
+ filemap_set_wb_err(mapping, error);
+
+ /* Record it in flags for now, for legacy callers */
+ if (error == -ENOSPC)
+ set_bit(AS_ENOSPC, &mapping->flags);
+ else
+ set_bit(AS_EIO, &mapping->flags);
}
static inline void mapping_set_unevictable(struct address_space *mapping)
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