From: Jeff Layton <jlayton@xxxxxxxxxx>
Add a new "error_state" struct to fsinfo, and teach the kernel to fill
that out from sb->s_wb_err. There are two fields:
wb_error_last: the most recently recorded errno for the filesystem
wb_error_cookie: this value will change vs. the previously fetched
value if a new error was recorded since it was last
checked. Callers should treat this as an opaque value
that can be compared to earlier fetched values.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
fs/fsinfo.c | 11 +++++++++++
include/uapi/linux/fsinfo.h | 13 +++++++++++++
2 files changed, 24 insertions(+)
diff --git a/fs/fsinfo.c b/fs/fsinfo.c
index f230124ffdf5..ea9d9821d76b 100644
--- a/fs/fsinfo.c
+++ b/fs/fsinfo.c
@@ -274,6 +274,16 @@ static int fsinfo_generic_seq_read(struct path *path, struct fsinfo_context *ctx
return m.count + 1;
}
+static int fsinfo_generic_error_state(struct path *path,
+ struct fsinfo_context *ctx)
+{
+ struct fsinfo_error_state *es = ctx->buffer;
+
+ es->wb_error_cookie = errseq_scrape(&path->dentry->d_sb->s_wb_err);
+ es->wb_error_last = es->wb_error_cookie & MAX_ERRNO;
+ return sizeof(*es);
+}
+
static const struct fsinfo_attribute fsinfo_common_attributes[] = {
FSINFO_VSTRUCT (FSINFO_ATTR_STATFS, fsinfo_generic_statfs),
FSINFO_VSTRUCT (FSINFO_ATTR_IDS, fsinfo_generic_ids),
@@ -286,6 +296,7 @@ static const struct fsinfo_attribute fsinfo_common_attributes[] = {
FSINFO_STRING (FSINFO_ATTR_SOURCE, fsinfo_generic_mount_source),
FSINFO_STRING (FSINFO_ATTR_CONFIGURATION, fsinfo_generic_seq_read),
FSINFO_STRING (FSINFO_ATTR_FS_STATISTICS, fsinfo_generic_seq_read),
+ FSINFO_VSTRUCT (FSINFO_ATTR_ERROR_STATE, fsinfo_generic_error_state),
FSINFO_LIST (FSINFO_ATTR_FSINFO_ATTRIBUTES, (void *)123UL),
FSINFO_VSTRUCT_N(FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO, (void *)123UL),
diff --git a/include/uapi/linux/fsinfo.h b/include/uapi/linux/fsinfo.h
index e40192d98648..dcd764771a7d 100644
--- a/include/uapi/linux/fsinfo.h
+++ b/include/uapi/linux/fsinfo.h
@@ -27,6 +27,7 @@
#define FSINFO_ATTR_SOURCE 0x09 /* Superblock source/device name (string) */
#define FSINFO_ATTR_CONFIGURATION 0x0a /* Superblock configuration/options (string) */
#define FSINFO_ATTR_FS_STATISTICS 0x0b /* Superblock filesystem statistics (string) */
+#define FSINFO_ATTR_ERROR_STATE 0x0c /* Superblock writeback error state */
#define FSINFO_ATTR_FSINFO_ATTRIBUTE_INFO 0x100 /* Information about attr N (for path) */
#define FSINFO_ATTR_FSINFO_ATTRIBUTES 0x101 /* List of supported attrs (for path) */
@@ -328,4 +329,16 @@ struct fsinfo_afs_server_address {
#define FSINFO_ATTR_AFS_SERVER_ADDRESSES__STRUCT struct fsinfo_afs_server_address
+/*
+ * Information struct for fsinfo(FSINFO_ATTR_ERROR_STATE).
+ *
+ * Retrieve the error state for a filesystem.
+ */
+struct fsinfo_error_state {
+ __u32 wb_error_cookie; /* writeback error cookie */
+ __u32 wb_error_last; /* latest writeback error */
+};
+
+#define FSINFO_ATTR_ERROR_STATE__STRUCT struct fsinfo_error_state
+
#endif /* _UAPI_LINUX_FSINFO_H */
