# define D_SPLICE_ALIAS_RACE
#endif
+/* Workaround for RH 7.5 which introduced file operation iterate() but requires
+ * each file->f_mode to be marked with FMODE_KABI_ITERATE. Instead OpenAFS will
+ * continue to use file opearation readdir() in this case.
+ */
+#if defined(STRUCT_FILE_OPERATIONS_HAS_ITERATE) && !defined(FMODE_KABI_ITERATE)
+#define USE_FOP_ITERATE 1
+#else
+#undef USE_FOP_ITERATE
+#endif
+
int cachefs_noreadpage = 0;
extern struct backing_dev_info *afs_backing_dev_info;
* handling and use of bulkstats will need to be reflected here as well.
*/
static int
-#if defined(STRUCT_FILE_OPERATIONS_HAS_ITERATE)
+#if defined(USE_FOP_ITERATE)
afs_linux_readdir(struct file *fp, struct dir_context *ctx)
#else
afs_linux_readdir(struct file *fp, void *dirbuf, filldir_t filldir)
*/
while ((avc->f.states & CStatd)
&& (tdc->dflags & DFFetching)
- && hsame(avc->f.m.DataVersion, tdc->f.versionNo)) {
+ && afs_IsDCacheFresh(tdc, avc)) {
ReleaseReadLock(&tdc->lock);
ReleaseWriteLock(&avc->lock);
afs_osi_Sleep(&tdc->validPos);
ObtainReadLock(&tdc->lock);
}
if (!(avc->f.states & CStatd)
- || !hsame(avc->f.m.DataVersion, tdc->f.versionNo)) {
+ || !afs_IsDCacheFresh(tdc, avc)) {
ReleaseReadLock(&tdc->lock);
ReleaseWriteLock(&avc->lock);
afs_PutDCache(tdc);
* takes an offset in units of blobs, rather than bytes.
*/
code = 0;
-#if defined(STRUCT_FILE_OPERATIONS_HAS_ITERATE)
+#if defined(USE_FOP_ITERATE)
offset = ctx->pos;
#else
offset = (int) fp->f_pos;
#endif
while (1) {
+ dirpos = 0;
code = BlobScan(tdc, offset, &dirpos);
- if (code || !dirpos)
- break;
+ if (code == 0 && dirpos == 0) {
+ /* We've reached EOF of the dir blob, so we can stop looking for
+ * entries. */
+ break;
+ }
- code = afs_dir_GetVerifiedBlob(tdc, dirpos, &entry);
+ if (code == 0) {
+ code = afs_dir_GetVerifiedBlob(tdc, dirpos, &entry);
+ }
if (code) {
if (!(avc->f.states & CCorrupt)) {
struct cell *tc = afs_GetCellStale(avc->f.fid.Cell, READ_LOCK);
* holding the GLOCK.
*/
AFS_GUNLOCK();
-#if defined(STRUCT_FILE_OPERATIONS_HAS_ITERATE)
+#if defined(USE_FOP_ITERATE)
/* dir_emit returns a bool - true when it succeeds.
* Inverse the result to fit with how we check "code" */
code = !dir_emit(ctx, de->name, len, ino, type);
code = 0;
unlock_out:
-#if defined(STRUCT_FILE_OPERATIONS_HAS_ITERATE)
+#if defined(USE_FOP_ITERATE)
ctx->pos = (loff_t) offset;
#else
fp->f_pos = (loff_t) offset;
struct file_operations afs_dir_fops = {
.read = generic_read_dir,
-#if defined(STRUCT_FILE_OPERATIONS_HAS_ITERATE)
+#if defined(USE_FOP_ITERATE)
.iterate = afs_linux_readdir,
#else
.readdir = afs_linux_readdir,
return hgetlo(pvcp->f.m.DataVersion);
}
-#ifdef D_SPLICE_ALIAS_RACE
+static inline int
+filter_enoent(int code)
+{
+#ifdef HAVE_LINUX_FATAL_SIGNAL_PENDING
+ if (code == ENOENT && fatal_signal_pending(current)) {
+ return EINTR;
+ }
+#endif
+ return code;
+}
+
+#ifndef D_SPLICE_ALIAS_RACE
+
+static inline void dentry_race_lock(void) {}
+static inline void dentry_race_unlock(void) {}
+
+#else
+
+# if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
+static DEFINE_MUTEX(dentry_race_sem);
+# else
+static DECLARE_MUTEX(dentry_race_sem);
+# endif
+
+static inline void
+dentry_race_lock(void)
+{
+ mutex_lock(&dentry_race_sem);
+}
+static inline void
+dentry_race_unlock(void)
+{
+ mutex_unlock(&dentry_race_sem);
+}
+
/* Leave some trace that this code is enabled; otherwise it's pretty hard to
* tell. */
static __attribute__((used)) const char dentry_race_marker[] = "d_splice_alias race workaround enabled";
{
int raced = 0;
if (!dp->d_inode) {
- struct dentry *parent = dget_parent(dp);
-
/* In Linux, before commit 4919c5e45a91b5db5a41695fe0357fbdff0d5767,
* d_splice_alias can momentarily hash a dentry before it's fully
* populated. This only happens for a moment, since it's unhashed again
* __d_lookup, and then given to us.
*
* So check if the dentry is unhashed; if it is, then the dentry is not
- * valid. We lock the parent inode to ensure that d_splice_alias is no
- * longer running (the inode mutex will be held during
- * afs_linux_lookup). Locking d_lock is required to check the dentry's
+ * valid. We lock dentry_race_lock() to ensure that d_splice_alias is
+ * no longer running. Locking d_lock is required to check the dentry's
* flags, so lock that, too.
*/
- afs_linux_lock_inode(parent->d_inode);
+ dentry_race_lock();
spin_lock(&dp->d_lock);
if (d_unhashed(dp)) {
raced = 1;
}
spin_unlock(&dp->d_lock);
- afs_linux_unlock_inode(parent->d_inode);
-
- dput(parent);
+ dentry_race_unlock();
}
return raced;
}
credp = crref();
}
code = afs_lookup(pvcp, (char *)dp->d_name.name, &tvc, credp);
+ code = filter_enoent(code);
if (code) {
/* We couldn't perform the lookup, so we're not okay. */
AFS_GLOCK();
code = afs_lookup(VTOAFS(dip), (char *)comp, &vcp, credp);
+ code = filter_enoent(code);
if (code == ENOENT) {
/* It's ok for the file to not be found. That's noted by the caller by
* seeing that the dp->d_inode field is NULL (set by d_splice_alias or
igrab(ip);
#endif
+ dentry_race_lock();
newdp = d_splice_alias(ip, dp);
+ dentry_race_unlock();
done:
crfree(credp);
* If task is NULL, the page copy occurs syncronously, and the routine
* returns with page still locked. If task is non-NULL, then page copies
* may occur in the background, and the page will be unlocked when it is
- * ready for use.
+ * ready for use. Note that if task is non-NULL and we encounter an error
+ * before we start the background copy, we MUST unlock 'page' before we return.
*/
static int
afs_linux_read_cache(struct file *cachefp, struct page *page,
if (!PageUptodate(cachepage)) {
ClearPageError(cachepage);
- code = cachemapping->a_ops->readpage(NULL, cachepage);
+ /* Note that ->readpage always handles unlocking the given page, even
+ * when an error is returned. */
+ code = cachemapping->a_ops->readpage(NULL, cachepage);
if (!code && !task) {
wait_on_page_locked(cachepage);
}
}
}
+ out:
if (code && task) {
unlock_page(page);
}
-out:
if (cachepage)
put_page(cachepage);
ObtainReadLock(&tdc->lock);
/* Is the dcache we've been given currently up to date */
- if (!hsame(avc->f.m.DataVersion, tdc->f.versionNo) ||
+ if (!afs_IsDCacheFresh(tdc, avc) ||
(tdc->dflags & DFFetching))
goto out;
/* XXX - I suspect we should be locking the inodes before we use them! */
AFS_GUNLOCK();
cacheFp = afs_linux_raw_open(&tdc->f.inode);
+ osi_Assert(cacheFp);
if (!cacheFp->f_dentry->d_inode->i_mapping->a_ops->readpage) {
cachefs_noreadpage = 1;
AFS_GLOCK();
AFS_GLOCK();
if ((tdc = afs_FindDCache(avc, offset))) {
ObtainReadLock(&tdc->lock);
- if (!hsame(avc->f.m.DataVersion, tdc->f.versionNo) ||
+ if (!afs_IsDCacheFresh(tdc, avc) ||
(tdc->dflags & DFFetching)) {
ReleaseReadLock(&tdc->lock);
afs_PutDCache(tdc);
AFS_GUNLOCK();
if (tdc) {
cacheFp = afs_linux_raw_open(&tdc->f.inode);
+ osi_Assert(cacheFp);
if (!cacheFp->f_dentry->d_inode->i_mapping->a_ops->readpage) {
cachefs_noreadpage = 1;
goto out;
if (!pagevec_add(&lrupv, page))
__pagevec_lru_add_file(&lrupv);
+ /* Note that add_to_page_cache() locked 'page'.
+ * afs_linux_read_cache() is guaranteed to handle unlocking it. */
afs_linux_read_cache(cacheFp, page, tdc->f.chunk, &lrupv, task);
}
put_page(page);
int code;
page = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page) {
+ return -ENOMEM;
+ }
+
*pagep = page;
code = afs_linux_prepare_write(file, page, from, from + len);
git://git.openafs.org / openafs.git / blobdiff