[PATCH] add -o flush for fat
Fat is commonly used on removable media. Mounting with -o flush tells the
FS to write things to disk as quickly as possible. It is like -o sync, but
much faster (and not as safe).
Signed-off-by: Chris Mason <mason@suse.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 1ee2523..d50fc47 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -13,6 +13,7 @@
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
+#include <linux/blkdev.h>
int fat_generic_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
@@ -112,6 +113,16 @@
}
}
+static int fat_file_release(struct inode *inode, struct file *filp)
+{
+ if ((filp->f_mode & FMODE_WRITE) &&
+ MSDOS_SB(inode->i_sb)->options.flush) {
+ fat_flush_inodes(inode->i_sb, inode, NULL);
+ blk_congestion_wait(WRITE, HZ/10);
+ }
+ return 0;
+}
+
const struct file_operations fat_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
@@ -121,6 +132,7 @@
.aio_read = generic_file_aio_read,
.aio_write = generic_file_aio_write,
.mmap = generic_file_mmap,
+ .release = fat_file_release,
.ioctl = fat_generic_ioctl,
.fsync = file_fsync,
.sendfile = generic_file_sendfile,
@@ -289,6 +301,7 @@
lock_kernel();
fat_free(inode, nr_clusters);
unlock_kernel();
+ fat_flush_inodes(inode->i_sb, inode, NULL);
}
struct inode_operations fat_file_inode_operations = {
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index ab96ae8..0457380 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -24,6 +24,7 @@
#include <linux/vfs.h>
#include <linux/parser.h>
#include <linux/uio.h>
+#include <linux/writeback.h>
#include <asm/unaligned.h>
#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
@@ -853,7 +854,7 @@
Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
- Opt_obsolate, Opt_err,
+ Opt_obsolate, Opt_flush, Opt_err,
};
static match_table_t fat_tokens = {
@@ -885,7 +886,8 @@
{Opt_obsolate, "cvf_format=%20s"},
{Opt_obsolate, "cvf_options=%100s"},
{Opt_obsolate, "posix"},
- {Opt_err, NULL}
+ {Opt_flush, "flush"},
+ {Opt_err, NULL},
};
static match_table_t msdos_tokens = {
{Opt_nodots, "nodots"},
@@ -1026,6 +1028,9 @@
return 0;
opts->codepage = option;
break;
+ case Opt_flush:
+ opts->flush = 1;
+ break;
/* msdos specific */
case Opt_dots:
@@ -1425,6 +1430,56 @@
EXPORT_SYMBOL_GPL(fat_fill_super);
+/*
+ * helper function for fat_flush_inodes. This writes both the inode
+ * and the file data blocks, waiting for in flight data blocks before
+ * the start of the call. It does not wait for any io started
+ * during the call
+ */
+static int writeback_inode(struct inode *inode)
+{
+
+ int ret;
+ struct address_space *mapping = inode->i_mapping;
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_NONE,
+ .nr_to_write = 0,
+ };
+ /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
+ * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
+ * and filemap_fdatawrite is used for the data blocks
+ */
+ ret = sync_inode(inode, &wbc);
+ if (!ret)
+ ret = filemap_fdatawrite(mapping);
+ return ret;
+}
+
+/*
+ * write data and metadata corresponding to i1 and i2. The io is
+ * started but we do not wait for any of it to finish.
+ *
+ * filemap_flush is used for the block device, so if there is a dirty
+ * page for a block already in flight, we will not wait and start the
+ * io over again
+ */
+int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
+{
+ int ret = 0;
+ if (!MSDOS_SB(sb)->options.flush)
+ return 0;
+ if (i1)
+ ret = writeback_inode(i1);
+ if (!ret && i2)
+ ret = writeback_inode(i2);
+ if (!ret && sb) {
+ struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
+ ret = filemap_flush(mapping);
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(fat_flush_inodes);
+
static int __init init_fat_fs(void)
{
int err;
diff --git a/fs/msdos/namei.c b/fs/msdos/namei.c
index 9e44158..d220165 100644
--- a/fs/msdos/namei.c
+++ b/fs/msdos/namei.c
@@ -280,7 +280,7 @@
struct nameidata *nd)
{
struct super_block *sb = dir->i_sb;
- struct inode *inode;
+ struct inode *inode = NULL;
struct fat_slot_info sinfo;
struct timespec ts;
unsigned char msdos_name[MSDOS_NAME];
@@ -316,6 +316,8 @@
d_instantiate(dentry, inode);
out:
unlock_kernel();
+ if (!err)
+ err = fat_flush_inodes(sb, dir, inode);
return err;
}
@@ -348,6 +350,8 @@
fat_detach(inode);
out:
unlock_kernel();
+ if (!err)
+ err = fat_flush_inodes(inode->i_sb, dir, inode);
return err;
}
@@ -401,6 +405,7 @@
d_instantiate(dentry, inode);
unlock_kernel();
+ fat_flush_inodes(sb, dir, inode);
return 0;
out_free:
@@ -430,6 +435,8 @@
fat_detach(inode);
out:
unlock_kernel();
+ if (!err)
+ err = fat_flush_inodes(inode->i_sb, dir, inode);
return err;
}
@@ -635,6 +642,8 @@
new_dir, new_msdos_name, new_dentry, is_hid);
out:
unlock_kernel();
+ if (!err)
+ err = fat_flush_inodes(old_dir->i_sb, old_dir, new_dir);
return err;
}
diff --git a/include/linux/msdos_fs.h b/include/linux/msdos_fs.h
index bae62d6..ce6c858 100644
--- a/include/linux/msdos_fs.h
+++ b/include/linux/msdos_fs.h
@@ -204,6 +204,7 @@
unicode_xlate:1, /* create escape sequences for unhandled Unicode */
numtail:1, /* Does first alias have a numeric '~1' type tail? */
atari:1, /* Use Atari GEMDOS variation of MS-DOS fs */
+ flush:1, /* write things quickly */
nocase:1; /* Does this need case conversion? 0=need case conversion*/
};
@@ -412,6 +413,8 @@
extern int fat_fill_super(struct super_block *sb, void *data, int silent,
struct inode_operations *fs_dir_inode_ops, int isvfat);
+extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
+ struct inode *i2);
/* fat/misc.c */
extern void fat_fs_panic(struct super_block *s, const char *fmt, ...);
extern void fat_clusters_flush(struct super_block *sb);