The patch titled
Subject: fs: return EAGAIN when O_NONBLOCK write should block on frozen fs
has been added to the -mm tree. Its filename is
fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Jan Kara <jack@xxxxxxx>
Subject: fs: return EAGAIN when O_NONBLOCK write should block on frozen fs
When user asks for O_NONBLOCK behavior for a file descriptor, return
EAGAIN instead of blocking on a frozen filesystem.
This is needed so we can fix a hang with BSD accounting on frozen
filesystems.
Signed-off-by: Jan Kara <jack@xxxxxxx>
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxxx>
Cc: Nikola Ciprich <nikola.ciprich@xxxxxxxxxxx>
Cc: Marco Stornelli <marco.stornelli@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/file.c | 3 ++-
fs/cifs/file.c | 3 ++-
fs/fuse/file.c | 3 ++-
fs/ntfs/file.c | 3 ++-
fs/ocfs2/file.c | 3 ++-
fs/splice.c | 3 ++-
fs/xfs/xfs_file.c | 3 ++-
include/linux/fs.h | 10 ++++++++++
mm/filemap.c | 3 ++-
9 files changed, 26 insertions(+), 8 deletions(-)
diff -puN fs/btrfs/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs fs/btrfs/file.c
--- a/fs/btrfs/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs
+++ a/fs/btrfs/file.c
@@ -1509,7 +1509,8 @@ static ssize_t btrfs_file_aio_write(stru
size_t count, ocount;
bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
- sb_start_write(inode->i_sb);
+ if (!sb_start_file_write(file))
+ return -EAGAIN;
mutex_lock(&inode->i_mutex);
diff -puN fs/cifs/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs fs/cifs/file.c
--- a/fs/cifs/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs
+++ a/fs/cifs/file.c
@@ -2510,7 +2510,8 @@ cifs_writev(struct kiocb *iocb, const st
BUG_ON(iocb->ki_pos != pos);
- sb_start_write(inode->i_sb);
+ if (!sb_start_file_write(file))
+ return -EAGAIN;
/*
* We need to hold the sem to be sure nobody modifies lock list
diff -puN fs/fuse/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs fs/fuse/file.c
--- a/fs/fuse/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs
+++ a/fs/fuse/file.c
@@ -971,7 +971,8 @@ static ssize_t fuse_file_aio_write(struc
return err;
count = ocount;
- sb_start_write(inode->i_sb);
+ if (!sb_start_file_write(file))
+ return -EAGAIN;
mutex_lock(&inode->i_mutex);
/* We can write back this queue in page reclaim */
diff -puN fs/ntfs/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs fs/ntfs/file.c
--- a/fs/ntfs/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs
+++ a/fs/ntfs/file.c
@@ -2129,7 +2129,8 @@ static ssize_t ntfs_file_aio_write(struc
BUG_ON(iocb->ki_pos != pos);
- sb_start_write(inode->i_sb);
+ if (!sb_start_file_write(file))
+ return -EAGAIN;
mutex_lock(&inode->i_mutex);
ret = ntfs_file_aio_write_nolock(iocb, iov, nr_segs, &iocb->ki_pos);
mutex_unlock(&inode->i_mutex);
diff -puN fs/ocfs2/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs fs/ocfs2/file.c
--- a/fs/ocfs2/file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs
+++ a/fs/ocfs2/file.c
@@ -2247,7 +2247,8 @@ static ssize_t ocfs2_file_aio_write(stru
if (iocb->ki_left == 0)
return 0;
- sb_start_write(inode->i_sb);
+ if (!sb_start_file_write(file))
+ return -EAGAIN;
appending = file->f_flags & O_APPEND ? 1 : 0;
direct_io = file->f_flags & O_DIRECT ? 1 : 0;
diff -puN fs/splice.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs fs/splice.c
--- a/fs/splice.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs
+++ a/fs/splice.c
@@ -998,7 +998,8 @@ generic_file_splice_write(struct pipe_in
};
ssize_t ret;
- sb_start_write(inode->i_sb);
+ if (!sb_start_file_write(out))
+ return -EAGAIN;
pipe_lock(pipe);
diff -puN fs/xfs/xfs_file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs fs/xfs/xfs_file.c
--- a/fs/xfs/xfs_file.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs
+++ a/fs/xfs/xfs_file.c
@@ -775,7 +775,8 @@ xfs_file_aio_write(
if (ocount == 0)
return 0;
- sb_start_write(inode->i_sb);
+ if (!sb_start_file_write(file))
+ return -EAGAIN;
if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
ret = -EIO;
diff -puN include/linux/fs.h~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs include/linux/fs.h
--- a/include/linux/fs.h~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs
+++ a/include/linux/fs.h
@@ -1400,6 +1400,16 @@ static inline int sb_start_write_trylock
return __sb_start_write(sb, SB_FREEZE_WRITE, false);
}
+/*
+ * sb_start_write() for writing into a file. When file has O_NONBLOCK set,
+ * we use trylock semantics, otherwise we block on frozen filesystem.
+ */
+static inline int sb_start_file_write(struct file *file)
+{
+ return __sb_start_write(file->f_mapping->host->i_sb, SB_FREEZE_WRITE,
+ !(file->f_flags & O_NONBLOCK));
+}
+
/**
* sb_start_pagefault - get write access to a superblock from a page fault
* @sb: the super we write to
diff -puN mm/filemap.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs mm/filemap.c
--- a/mm/filemap.c~fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs
+++ a/mm/filemap.c
@@ -2527,7 +2527,8 @@ ssize_t generic_file_aio_write(struct ki
BUG_ON(iocb->ki_pos != pos);
- sb_start_write(inode->i_sb);
+ if (!sb_start_file_write(file))
+ return -EAGAIN;
mutex_lock(&inode->i_mutex);
ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
mutex_unlock(&inode->i_mutex);
_
Patches currently in -mm which might be from jack@xxxxxxx are
linux-next.patch
fs-change-return-values-from-eacces-to-eperm.patch
fs-return-eagain-when-o_nonblock-write-should-block-on-frozen-fs.patch
fs-fix-hang-with-bsd-accounting-on-frozen-filesystem.patch
ocfs2-add-freeze-protection-to-ocfs2_file_splice_write.patch
bdi-allow-block-devices-to-say-that-they-require-stable-page-writes.patch
mm-only-enforce-stable-page-writes-if-the-backing-device-requires-it.patch
9pfs-fix-filesystem-to-wait-for-stable-page-writeback.patch
block-optionally-snapshot-page-contents-to-provide-stable-pages-during-write.patch
ocfs2-wait-for-page-writeback-to-provide-stable-pages.patch
ubifs-wait-for-page-writeback-to-provide-stable-pages.patch
hfsplus-add-osx-prefix-for-handling-namespace-of-mac-os-x-extended-attributes.patch
hfsplus-add-on-disk-layout-declarations-related-to-attributes-tree.patch
hfsplus-add-functionality-of-manipulating-by-records-in-attributes-tree.patch
hfsplus-rework-functionality-of-getting-setting-and-deleting-of-extended-attributes.patch
hfsplus-add-support-of-manipulation-by-attributes-file.patch
hfsplus-fix-issue-with-unzeroed-unused-b-tree-nodes.patch
ocfs2-fix-possible-use-after-free-with-aio.patch
fs-direct-ioc-fix-possible-use-after-free-with-aio.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
