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-rw-r--r--mm/filemap.c126
1 files changed, 109 insertions, 17 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index 2e906ef52143..3247b4208034 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -309,6 +309,16 @@ int filemap_check_errors(struct address_space *mapping)
}
EXPORT_SYMBOL(filemap_check_errors);
+static int filemap_check_and_keep_errors(struct address_space *mapping)
+{
+ /* Check for outstanding write errors */
+ if (test_bit(AS_EIO, &mapping->flags))
+ return -EIO;
+ if (test_bit(AS_ENOSPC, &mapping->flags))
+ return -ENOSPC;
+ return 0;
+}
+
/**
* __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
* @mapping: address space structure to write
@@ -408,17 +418,16 @@ bool filemap_range_has_page(struct address_space *mapping,
}
EXPORT_SYMBOL(filemap_range_has_page);
-static int __filemap_fdatawait_range(struct address_space *mapping,
+static void __filemap_fdatawait_range(struct address_space *mapping,
loff_t start_byte, loff_t end_byte)
{
pgoff_t index = start_byte >> PAGE_SHIFT;
pgoff_t end = end_byte >> PAGE_SHIFT;
struct pagevec pvec;
int nr_pages;
- int ret = 0;
if (end_byte < start_byte)
- goto out;
+ return;
pagevec_init(&pvec, 0);
while ((index <= end) &&
@@ -435,14 +444,11 @@ static int __filemap_fdatawait_range(struct address_space *mapping,
continue;
wait_on_page_writeback(page);
- if (TestClearPageError(page))
- ret = -EIO;
+ ClearPageError(page);
}
pagevec_release(&pvec);
cond_resched();
}
-out:
- return ret;
}
/**
@@ -462,14 +468,8 @@ out:
int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte,
loff_t end_byte)
{
- int ret, ret2;
-
- ret = __filemap_fdatawait_range(mapping, start_byte, end_byte);
- ret2 = filemap_check_errors(mapping);
- if (!ret)
- ret = ret2;
-
- return ret;
+ __filemap_fdatawait_range(mapping, start_byte, end_byte);
+ return filemap_check_errors(mapping);
}
EXPORT_SYMBOL(filemap_fdatawait_range);
@@ -485,15 +485,17 @@ EXPORT_SYMBOL(filemap_fdatawait_range);
* call sites are system-wide / filesystem-wide data flushers: e.g. sync(2),
* fsfreeze(8)
*/
-void filemap_fdatawait_keep_errors(struct address_space *mapping)
+int filemap_fdatawait_keep_errors(struct address_space *mapping)
{
loff_t i_size = i_size_read(mapping->host);
if (i_size == 0)
- return;
+ return 0;
__filemap_fdatawait_range(mapping, 0, i_size - 1);
+ return filemap_check_and_keep_errors(mapping);
}
+EXPORT_SYMBOL(filemap_fdatawait_keep_errors);
/**
* filemap_fdatawait - wait for all under-writeback pages to complete
@@ -535,6 +537,9 @@ int filemap_write_and_wait(struct address_space *mapping)
int err2 = filemap_fdatawait(mapping);
if (!err)
err = err2;
+ } else {
+ /* Clear any previously stored errors */
+ filemap_check_errors(mapping);
}
} else {
err = filemap_check_errors(mapping);
@@ -569,6 +574,9 @@ int filemap_write_and_wait_range(struct address_space *mapping,
lstart, lend);
if (!err)
err = err2;
+ } else {
+ /* Clear any previously stored errors */
+ filemap_check_errors(mapping);
}
} else {
err = filemap_check_errors(mapping);
@@ -577,6 +585,90 @@ int filemap_write_and_wait_range(struct address_space *mapping,
}
EXPORT_SYMBOL(filemap_write_and_wait_range);
+void __filemap_set_wb_err(struct address_space *mapping, int err)
+{
+ errseq_t eseq = __errseq_set(&mapping->wb_err, err);
+
+ trace_filemap_set_wb_err(mapping, eseq);
+}
+EXPORT_SYMBOL(__filemap_set_wb_err);
+
+/**
+ * file_check_and_advance_wb_err - report wb error (if any) that was previously
+ * and advance wb_err to current one
+ * @file: struct file on which the error is being reported
+ *
+ * When userland calls fsync (or something like nfsd does the equivalent), we
+ * want to report any writeback errors that occurred since the last fsync (or
+ * since the file was opened if there haven't been any).
+ *
+ * Grab the wb_err from the mapping. If it matches what we have in the file,
+ * then just quickly return 0. The file is all caught up.
+ *
+ * If it doesn't match, then take the mapping value, set the "seen" flag in
+ * it and try to swap it into place. If it works, or another task beat us
+ * to it with the new value, then update the f_wb_err and return the error
+ * portion. The error at this point must be reported via proper channels
+ * (a'la fsync, or NFS COMMIT operation, etc.).
+ *
+ * While we handle mapping->wb_err with atomic operations, the f_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 file_check_and_advance_wb_err(struct file *file)
+{
+ int err = 0;
+ errseq_t old = READ_ONCE(file->f_wb_err);
+ struct address_space *mapping = file->f_mapping;
+
+ /* 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_file_check_and_advance_wb_err(file, old);
+ spin_unlock(&file->f_lock);
+ }
+ return err;
+}
+EXPORT_SYMBOL(file_check_and_advance_wb_err);
+
+/**
+ * file_write_and_wait_range - write out & wait on a file range
+ * @file: file pointing to address_space with pages
+ * @lstart: offset in bytes where the range starts
+ * @lend: offset in bytes where the range ends (inclusive)
+ *
+ * Write out and wait upon file offsets lstart->lend, inclusive.
+ *
+ * Note that @lend is inclusive (describes the last byte to be written) so
+ * that this function can be used to write to the very end-of-file (end = -1).
+ *
+ * After writing out and waiting on the data, we check and advance the
+ * f_wb_err cursor to the latest value, and return any errors detected there.
+ */
+int file_write_and_wait_range(struct file *file, loff_t lstart, loff_t lend)
+{
+ int err = 0, err2;
+ struct address_space *mapping = file->f_mapping;
+
+ if ((!dax_mapping(mapping) && mapping->nrpages) ||
+ (dax_mapping(mapping) && mapping->nrexceptional)) {
+ err = __filemap_fdatawrite_range(mapping, lstart, lend,
+ WB_SYNC_ALL);
+ /* See comment of filemap_write_and_wait() */
+ if (err != -EIO)
+ __filemap_fdatawait_range(mapping, lstart, lend);
+ }
+ err2 = file_check_and_advance_wb_err(file);
+ if (!err)
+ err = err2;
+ return err;
+}
+EXPORT_SYMBOL(file_write_and_wait_range);
+
/**
* replace_page_cache_page - replace a pagecache page with a new one
* @old: page to be replaced