From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/fs/sync.c | 205 ++++++++++++++++++++++++++++-----------------------
1 files changed, 113 insertions(+), 92 deletions(-)
diff --git a/kernel/fs/sync.c b/kernel/fs/sync.c
index 055daab..ad7a271 100644
--- a/kernel/fs/sync.c
+++ b/kernel/fs/sync.c
@@ -22,32 +22,13 @@
SYNC_FILE_RANGE_WAIT_AFTER)
/*
- * Do the filesystem syncing work. For simple filesystems
- * writeback_inodes_sb(sb) just dirties buffers with inodes so we have to
- * submit IO for these buffers via __sync_blockdev(). This also speeds up the
- * wait == 1 case since in that case write_inode() functions do
- * sync_dirty_buffer() and thus effectively write one block at a time.
- */
-static int __sync_filesystem(struct super_block *sb, int wait)
-{
- if (wait)
- sync_inodes_sb(sb);
- else
- writeback_inodes_sb(sb, WB_REASON_SYNC);
-
- if (sb->s_op->sync_fs)
- sb->s_op->sync_fs(sb, wait);
- return __sync_blockdev(sb->s_bdev, wait);
-}
-
-/*
* Write out and wait upon all dirty data associated with this
* superblock. Filesystem data as well as the underlying block
* device. Takes the superblock lock.
*/
int sync_filesystem(struct super_block *sb)
{
- int ret;
+ int ret = 0;
/*
* We need to be protected against the filesystem going from
@@ -61,12 +42,33 @@
if (sb_rdonly(sb))
return 0;
- ret = __sync_filesystem(sb, 0);
- if (ret < 0)
+ /*
+ * Do the filesystem syncing work. For simple filesystems
+ * writeback_inodes_sb(sb) just dirties buffers with inodes so we have
+ * to submit I/O for these buffers via __sync_blockdev(). This also
+ * speeds up the wait == 1 case since in that case write_inode()
+ * methods call sync_dirty_buffer() and thus effectively write one block
+ * at a time.
+ */
+ writeback_inodes_sb(sb, WB_REASON_SYNC);
+ if (sb->s_op->sync_fs) {
+ ret = sb->s_op->sync_fs(sb, 0);
+ if (ret)
+ return ret;
+ }
+ ret = __sync_blockdev(sb->s_bdev, 0);
+ if (ret)
return ret;
- return __sync_filesystem(sb, 1);
+
+ sync_inodes_sb(sb);
+ if (sb->s_op->sync_fs) {
+ ret = sb->s_op->sync_fs(sb, 1);
+ if (ret)
+ return ret;
+ }
+ return __sync_blockdev(sb->s_bdev, 1);
}
-EXPORT_SYMBOL(sync_filesystem);
+EXPORT_SYMBOL_NS(sync_filesystem, ANDROID_GKI_VFS_EXPORT_ONLY);
static void sync_inodes_one_sb(struct super_block *sb, void *arg)
{
@@ -76,7 +78,8 @@
static void sync_fs_one_sb(struct super_block *sb, void *arg)
{
- if (!sb_rdonly(sb) && sb->s_op->sync_fs)
+ if (!sb_rdonly(sb) && !(sb->s_iflags & SB_I_SKIP_SYNC) &&
+ sb->s_op->sync_fs)
sb->s_op->sync_fs(sb, *(int *)arg);
}
@@ -161,7 +164,7 @@
{
struct fd f = fdget(fd);
struct super_block *sb;
- int ret;
+ int ret, ret2;
if (!f.file)
return -EBADF;
@@ -171,8 +174,10 @@
ret = sync_filesystem(sb);
up_read(&sb->s_umount);
+ ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err);
+
fdput(f);
- return ret;
+ return ret ? ret : ret2;
}
/**
@@ -235,58 +240,10 @@
return do_fsync(fd, 1);
}
-/*
- * sys_sync_file_range() permits finely controlled syncing over a segment of
- * a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is
- * zero then sys_sync_file_range() will operate from offset out to EOF.
- *
- * The flag bits are:
- *
- * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range
- * before performing the write.
- *
- * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
- * range which are not presently under writeback. Note that this may block for
- * significant periods due to exhaustion of disk request structures.
- *
- * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
- * after performing the write.
- *
- * Useful combinations of the flag bits are:
- *
- * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE: ensures that all pages
- * in the range which were dirty on entry to sys_sync_file_range() are placed
- * under writeout. This is a start-write-for-data-integrity operation.
- *
- * SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which
- * are not presently under writeout. This is an asynchronous flush-to-disk
- * operation. Not suitable for data integrity operations.
- *
- * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for
- * completion of writeout of all pages in the range. This will be used after an
- * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait
- * for that operation to complete and to return the result.
- *
- * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|SYNC_FILE_RANGE_WAIT_AFTER:
- * a traditional sync() operation. This is a write-for-data-integrity operation
- * which will ensure that all pages in the range which were dirty on entry to
- * sys_sync_file_range() are committed to disk.
- *
- *
- * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any
- * I/O errors or ENOSPC conditions and will return those to the caller, after
- * clearing the EIO and ENOSPC flags in the address_space.
- *
- * It should be noted that none of these operations write out the file's
- * metadata. So unless the application is strictly performing overwrites of
- * already-instantiated disk blocks, there are no guarantees here that the data
- * will be available after a crash.
- */
-int ksys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
- unsigned int flags)
+int sync_file_range(struct file *file, loff_t offset, loff_t nbytes,
+ unsigned int flags)
{
int ret;
- struct fd f;
struct address_space *mapping;
loff_t endbyte; /* inclusive */
umode_t i_mode;
@@ -326,41 +283,105 @@
else
endbyte--; /* inclusive */
- ret = -EBADF;
- f = fdget(fd);
- if (!f.file)
- goto out;
-
- i_mode = file_inode(f.file)->i_mode;
+ i_mode = file_inode(file)->i_mode;
ret = -ESPIPE;
if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) &&
!S_ISLNK(i_mode))
- goto out_put;
+ goto out;
- mapping = f.file->f_mapping;
+ mapping = file->f_mapping;
ret = 0;
if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
- ret = file_fdatawait_range(f.file, offset, endbyte);
+ ret = file_fdatawait_range(file, offset, endbyte);
if (ret < 0)
- goto out_put;
+ goto out;
}
if (flags & SYNC_FILE_RANGE_WRITE) {
+ int sync_mode = WB_SYNC_NONE;
+
+ if ((flags & SYNC_FILE_RANGE_WRITE_AND_WAIT) ==
+ SYNC_FILE_RANGE_WRITE_AND_WAIT)
+ sync_mode = WB_SYNC_ALL;
+
ret = __filemap_fdatawrite_range(mapping, offset, endbyte,
- WB_SYNC_NONE);
+ sync_mode);
if (ret < 0)
- goto out_put;
+ goto out;
}
if (flags & SYNC_FILE_RANGE_WAIT_AFTER)
- ret = file_fdatawait_range(f.file, offset, endbyte);
+ ret = file_fdatawait_range(file, offset, endbyte);
-out_put:
- fdput(f);
out:
return ret;
}
+/*
+ * ksys_sync_file_range() permits finely controlled syncing over a segment of
+ * a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is
+ * zero then ksys_sync_file_range() will operate from offset out to EOF.
+ *
+ * The flag bits are:
+ *
+ * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range
+ * before performing the write.
+ *
+ * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
+ * range which are not presently under writeback. Note that this may block for
+ * significant periods due to exhaustion of disk request structures.
+ *
+ * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
+ * after performing the write.
+ *
+ * Useful combinations of the flag bits are:
+ *
+ * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE: ensures that all pages
+ * in the range which were dirty on entry to ksys_sync_file_range() are placed
+ * under writeout. This is a start-write-for-data-integrity operation.
+ *
+ * SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which
+ * are not presently under writeout. This is an asynchronous flush-to-disk
+ * operation. Not suitable for data integrity operations.
+ *
+ * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for
+ * completion of writeout of all pages in the range. This will be used after an
+ * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait
+ * for that operation to complete and to return the result.
+ *
+ * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|SYNC_FILE_RANGE_WAIT_AFTER
+ * (a.k.a. SYNC_FILE_RANGE_WRITE_AND_WAIT):
+ * a traditional sync() operation. This is a write-for-data-integrity operation
+ * which will ensure that all pages in the range which were dirty on entry to
+ * ksys_sync_file_range() are written to disk. It should be noted that disk
+ * caches are not flushed by this call, so there are no guarantees here that the
+ * data will be available on disk after a crash.
+ *
+ *
+ * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any
+ * I/O errors or ENOSPC conditions and will return those to the caller, after
+ * clearing the EIO and ENOSPC flags in the address_space.
+ *
+ * It should be noted that none of these operations write out the file's
+ * metadata. So unless the application is strictly performing overwrites of
+ * already-instantiated disk blocks, there are no guarantees here that the data
+ * will be available after a crash.
+ */
+int ksys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
+ unsigned int flags)
+{
+ int ret;
+ struct fd f;
+
+ ret = -EBADF;
+ f = fdget(fd);
+ if (f.file)
+ ret = sync_file_range(f.file, offset, nbytes, flags);
+
+ fdput(f);
+ return ret;
+}
+
SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
unsigned int, flags)
{
--
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