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authorLinus Torvalds <torvalds@linux-foundation.org>2009-11-02 12:23:21 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-11-02 12:23:21 -0800
commit1836d95928a0f41ada0cbb2a6c4e46b027db9491 (patch)
tree24ebf7cfd598dfef82247044fb3b65110fe22fc8 /fs
parent333a07437c31ea8c16a2b82071629a540ae1e50f (diff)
parent3e2796a90cf349527e50b3bc4d0b2f4019b1ce7a (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: 9p: fix readdir corner cases 9p: fix readlink 9p: fix a small bug in readdir for long directories
Diffstat (limited to 'fs')
-rw-r--r--fs/9p/vfs_dir.c93
-rw-r--r--fs/9p/vfs_inode.c5
2 files changed, 69 insertions, 29 deletions
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index 873cd31baa4..15cce53bf61 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -40,6 +40,24 @@
#include "fid.h"
/**
+ * struct p9_rdir - readdir accounting
+ * @mutex: mutex protecting readdir
+ * @head: start offset of current dirread buffer
+ * @tail: end offset of current dirread buffer
+ * @buf: dirread buffer
+ *
+ * private structure for keeping track of readdir
+ * allocated on demand
+ */
+
+struct p9_rdir {
+ struct mutex mutex;
+ int head;
+ int tail;
+ uint8_t *buf;
+};
+
+/**
* dt_type - return file type
* @mistat: mistat structure
*
@@ -70,56 +88,79 @@ static int v9fs_dir_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
int over;
struct p9_wstat st;
- int err;
+ int err = 0;
struct p9_fid *fid;
int buflen;
- char *statbuf;
- int n, i = 0;
+ int reclen = 0;
+ struct p9_rdir *rdir;
P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", filp->f_path.dentry->d_name.name);
fid = filp->private_data;
buflen = fid->clnt->msize - P9_IOHDRSZ;
- statbuf = kmalloc(buflen, GFP_KERNEL);
- if (!statbuf)
- return -ENOMEM;
-
- while (1) {
- err = v9fs_file_readn(filp, statbuf, NULL, buflen,
- fid->rdir_fpos);
- if (err <= 0)
- break;
-
- n = err;
- while (i < n) {
- err = p9stat_read(statbuf + i, buflen-i, &st,
- fid->clnt->dotu);
+
+ /* allocate rdir on demand */
+ if (!fid->rdir) {
+ rdir = kmalloc(sizeof(struct p9_rdir) + buflen, GFP_KERNEL);
+
+ if (rdir == NULL) {
+ err = -ENOMEM;
+ goto exit;
+ }
+ spin_lock(&filp->f_dentry->d_lock);
+ if (!fid->rdir) {
+ rdir->buf = (uint8_t *)rdir + sizeof(struct p9_rdir);
+ mutex_init(&rdir->mutex);
+ rdir->head = rdir->tail = 0;
+ fid->rdir = (void *) rdir;
+ rdir = NULL;
+ }
+ spin_unlock(&filp->f_dentry->d_lock);
+ kfree(rdir);
+ }
+ rdir = (struct p9_rdir *) fid->rdir;
+
+ err = mutex_lock_interruptible(&rdir->mutex);
+ while (err == 0) {
+ if (rdir->tail == rdir->head) {
+ err = v9fs_file_readn(filp, rdir->buf, NULL,
+ buflen, filp->f_pos);
+ if (err <= 0)
+ goto unlock_and_exit;
+
+ rdir->head = 0;
+ rdir->tail = err;
+ }
+
+ while (rdir->head < rdir->tail) {
+ err = p9stat_read(rdir->buf + rdir->head,
+ buflen - rdir->head, &st,
+ fid->clnt->dotu);
if (err) {
P9_DPRINTK(P9_DEBUG_VFS, "returned %d\n", err);
err = -EIO;
p9stat_free(&st);
- goto free_and_exit;
+ goto unlock_and_exit;
}
-
- i += st.size+2;
- fid->rdir_fpos += st.size+2;
+ reclen = st.size+2;
over = filldir(dirent, st.name, strlen(st.name),
filp->f_pos, v9fs_qid2ino(&st.qid), dt_type(&st));
- filp->f_pos += st.size+2;
-
p9stat_free(&st);
if (over) {
err = 0;
- goto free_and_exit;
+ goto unlock_and_exit;
}
+ rdir->head += reclen;
+ filp->f_pos += reclen;
}
}
-free_and_exit:
- kfree(statbuf);
+unlock_and_exit:
+ mutex_unlock(&rdir->mutex);
+exit:
return err;
}
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 5947628aefe..18f74ec4dce 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -994,8 +994,7 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
P9_DPRINTK(P9_DEBUG_VFS,
"%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
- retval = buflen;
-
+ retval = strnlen(buffer, buflen);
done:
kfree(st);
return retval;
@@ -1062,7 +1061,7 @@ static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
__putname(link);
link = ERR_PTR(len);
} else
- link[len] = 0;
+ link[min(len, PATH_MAX-1)] = 0;
}
nd_set_link(nd, link);