lkml.org 
[lkml]   [2017]   [Apr]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 06/10] orangefs: support llseek on directories
Date
This and the previous commit fix xfstests generic/257.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
---
fs/orangefs/dir.c | 48 ++++++++++++++++++++++++++++++++++--------------
1 file changed, 34 insertions(+), 14 deletions(-)

diff --git a/fs/orangefs/dir.c b/fs/orangefs/dir.c
index 3f82a73..c48220f 100644
--- a/fs/orangefs/dir.c
+++ b/fs/orangefs/dir.c
@@ -17,7 +17,7 @@
struct orangefs_dir {
__u64 token;
void *directory;
- size_t i, len;
+ size_t len;
int error;
};

@@ -124,31 +124,36 @@ static int orangefs_dir_fill(struct orangefs_inode_s *oi,
{
struct orangefs_khandle *khandle;
__u32 *len, padlen;
+ loff_t i;
char *s;
- while (od->i < od->len) {
- if (od->len < od->i + sizeof *len)
+ i = ctx->pos - 2;
+ while (i < od->len) {
+ if (od->len < i + sizeof *len)
goto eio;
- len = od->directory + od->i;
+ len = od->directory + i;
/* len does not include trailing zero but padlen does. */
padlen = (*len + 1) + (4 - (*len + 1)%4)%4;
- if (od->len < od->i + sizeof *len + padlen + sizeof *khandle)
+ if (od->len < i + sizeof *len + padlen + sizeof *khandle)
goto eio;
- s = od->directory + od->i + sizeof *len;
+ s = od->directory + i + sizeof *len;
if (s[*len] != 0)
goto eio;
- khandle = od->directory + od->i + sizeof *len + padlen;
+ khandle = od->directory + i + sizeof *len + padlen;

if (!dir_emit(ctx, s, *len, orangefs_khandle_to_ino(khandle),
DT_UNKNOWN))
return 0;
- od->i += sizeof *len + padlen + sizeof *khandle;
- od->i = od->i + (8 - od->i%8)%8;
- ctx->pos = 2 + od->i;
+ i += sizeof *len + padlen + sizeof *khandle;
+ i = i + (8 - i%8)%8;
+ ctx->pos = i + 2;
}
- BUG_ON(od->i > od->len);
+ BUG_ON(i > od->len);
return 0;
eio:
- gossip_err("orangefs_dir_fill: userspace returns corrupt data\n");
+ /*
+ * Here either data from userspace is corrupt or the application has
+ * sought to an invalid location.
+ */
od->error = -EIO;
return -EIO;
}
@@ -180,12 +185,27 @@ static int orangefs_dir_iterate(struct file *file, struct dir_context *ctx)

r = 0;

- if (od->i < od->len) {
+ /*
+ * Must read more if the user has sought past what has been read so far.
+ * Stop a user who has sought past the end.
+ */
+ while (od->token != ORANGEFS_READDIR_END && ctx->pos - 2 > od->len) {
+ r = orangefs_dir_more(oi, od, dentry);
+ if (r)
+ return r;
+ }
+ if (od->token == ORANGEFS_READDIR_END && ctx->pos - 2 > od->len) {
+ return -EIO;
+ }
+
+ /* Then try to fill if there's any left in the buffer. */
+ if (ctx->pos - 2 < od->len) {
r = orangefs_dir_fill(oi, od, dentry, ctx);
if (r)
return r;
}

+ /* Finally get some more and try to fill. */
if (od->token != ORANGEFS_READDIR_END) {
r = orangefs_dir_more(oi, od, dentry);
if (r)
@@ -213,7 +233,6 @@ static int orangefs_dir_open(struct inode *inode, struct file *file)
kfree(file->private_data);
return -ENOMEM;
}
- od->i = 0;
od->len = 0;
od->error = 0;
return 0;
@@ -229,6 +248,7 @@ static int orangefs_dir_release(struct inode *inode, struct file *file)
}

const struct file_operations orangefs_dir_operations = {
+ .llseek = default_llseek,
.read = generic_read_dir,
.iterate = orangefs_dir_iterate,
.open = orangefs_dir_open,
--
2.1.4
\
 
 \ /
  Last update: 2017-04-07 23:19    [W:0.232 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site