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From: Richard Weinberger <richard@nod.at>
To: user-mode-linux-devel@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org, richard@nod.at
Subject: [PATCH 03/15] hostfs: Allow fsync on directories
Date: Mon, 16 Mar 2015 12:41:07 +0100	[thread overview]
Message-ID: <1426506079-26183-4-git-send-email-richard@nod.at> (raw)
In-Reply-To: <1426506079-26183-1-git-send-email-richard@nod.at>

Historically hostfs did not open directories on the host filesystem
for performance and memory reasons.
But it turned out that this optimization has a drawback.
Calling fsync() on a hostfs directory returns immediately
with -EINVAL as fsync is not implemented.
While this is behavior is strictly speaking correct common userspace
like dpkg(1) stumbles over that and makes it impossible to use
hostfs as root filesystem.
The fix is easy, wire up the existing host open/fsync functions
to the directory file operations.

Reported-by: Daniel Gröber <dxld@darkboxed.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
---
 fs/hostfs/hostfs_kern.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 112ba5a..92b008f 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -295,7 +295,7 @@ static int hostfs_readdir(struct file *file, struct dir_context *ctx)
 	return 0;
 }
 
-static int hostfs_file_open(struct inode *ino, struct file *file)
+static int hostfs_open(struct inode *ino, struct file *file)
 {
 	char *name;
 	fmode_t mode = 0;
@@ -386,7 +386,7 @@ static const struct file_operations hostfs_file_fops = {
 	.write_iter	= generic_file_write_iter,
 	.write		= new_sync_write,
 	.mmap		= generic_file_mmap,
-	.open		= hostfs_file_open,
+	.open		= hostfs_open,
 	.release	= hostfs_file_release,
 	.fsync		= hostfs_fsync,
 };
@@ -395,6 +395,8 @@ static const struct file_operations hostfs_dir_fops = {
 	.llseek		= generic_file_llseek,
 	.iterate	= hostfs_readdir,
 	.read		= generic_read_dir,
+	.open		= hostfs_open,
+	.fsync		= hostfs_fsync,
 };
 
 static int hostfs_writepage(struct page *page, struct writeback_control *wbc)
-- 
2.3.2


  parent reply	other threads:[~2015-03-16 11:46 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-16 11:41 Hostfs updates Richard Weinberger
2015-03-16 11:41 ` [PATCH 01/15] hostfs: hostfs_file_open: Switch to data locking model Richard Weinberger
2015-03-16 11:41 ` [PATCH 02/15] hostfs: hostfs_file_open: Fix a fd leak in hostfs_file_open Richard Weinberger
2015-03-16 11:41 ` Richard Weinberger [this message]
2015-03-16 11:41 ` [PATCH 04/15] hostfs: Handle bogus st.mode Richard Weinberger
2015-03-16 11:41 ` [PATCH 05/15] hostfs: Make hostfs_readpage more readable Richard Weinberger
2015-03-16 11:41 ` [PATCH 06/15] hostfs: Add a BUG_ON to detect behavior changes of dentry_path_raw() Richard Weinberger
2015-03-16 11:41 ` [PATCH 07/15] hostfs: Remove open coded strcpy() Richard Weinberger
2015-03-16 12:03   ` [uml-devel] " Geert Uytterhoeven
2015-03-16 12:18     ` Richard Weinberger
2015-03-16 12:44       ` Geert Uytterhoeven
2015-03-16 11:41 ` [PATCH 08/15] hostfs: Use __getname() in follow_link Richard Weinberger
2015-03-16 11:41 ` [PATCH 09/15] hostfs: Report append flag in ->show_options() Richard Weinberger
2015-03-16 11:41 ` [PATCH 10/15] hostfs: Remove superfluous test in hostfs_open() Richard Weinberger
2015-03-16 11:41 ` [PATCH 11/15] hostfs: hostfs_open: Reset open flags upon each retry Richard Weinberger
2015-03-16 11:41 ` [PATCH 12/15] hostfs: Remove superfluous initializations in hostfs_open() Richard Weinberger
2015-03-16 11:41 ` [PATCH 13/15] hostfs: Set page flags in hostfs_readpage() correctly Richard Weinberger
2015-03-16 11:41 ` [PATCH 14/15] hostfs: Use page_offset() Richard Weinberger
2015-03-16 11:41 ` [PATCH 15/15] hostfs: No need to box and later unbox the file mode Richard Weinberger

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