| Message ID | 1405957558-18476-13-git-send-email-pshilovsky@samba.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com> On Mon, Jul 21, 2014 at 10:45 AM, Pavel Shilovsky <pshilovsky@samba.org> wrote: > If a server changes maximum buffer size for read (rsize) requests > on reconnect we can fail on repeating with a big size buffer on > -EAGAIN error in readpages. Fix this by checking rsize all the > time before repeating requests. > > Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> > --- > fs/cifs/file.c | 41 ++++++++++++++++++++++++++--------------- > 1 file changed, 26 insertions(+), 15 deletions(-) > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index bec48f1..d627918 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -3349,6 +3349,8 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list, > unsigned int expected_index; > int rc; > > + INIT_LIST_HEAD(tmplist); > + > page = list_entry(page_list->prev, struct page, lru); > > /* > @@ -3404,19 +3406,10 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, > struct list_head tmplist; > struct cifsFileInfo *open_file = file->private_data; > struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); > - unsigned int rsize = cifs_sb->rsize; > + struct TCP_Server_Info *server; > pid_t pid; > > /* > - * Give up immediately if rsize is too small to read an entire page. > - * The VFS will fall back to readpage. We should never reach this > - * point however since we set ra_pages to 0 when the rsize is smaller > - * than a cache page. > - */ > - if (unlikely(rsize < PAGE_CACHE_SIZE)) > - return 0; > - > - /* > * Reads as many pages as possible from fscache. Returns -ENOBUFS > * immediately if the cookie is negative > * > @@ -3434,7 +3427,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, > pid = current->tgid; > > rc = 0; > - INIT_LIST_HEAD(&tmplist); > + server = tlink_tcon(open_file->tlink)->ses->server; > > cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n", > __func__, file, mapping, num_pages); > @@ -3456,8 +3449,17 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, > struct page *page, *tpage; > struct cifs_readdata *rdata; > > - rc = readpages_get_pages(mapping, page_list, rsize, &tmplist, > - &nr_pages, &offset, &bytes); > + /* > + * Give up immediately if rsize is too small to read an entire > + * page. The VFS will fall back to readpage. We should never > + * reach this point however since we set ra_pages to 0 when the > + * rsize is smaller than a cache page. > + */ > + if (unlikely(cifs_sb->rsize < PAGE_CACHE_SIZE)) > + return 0; > + > + rc = readpages_get_pages(mapping, page_list, cifs_sb->rsize, > + &tmplist, &nr_pages, &offset, &bytes); > if (rc) > break; > > @@ -3487,15 +3489,24 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, > rdata->pages[rdata->nr_pages++] = page; > } > > - rc = cifs_retry_async_readv(rdata); > - if (rc != 0) { > + if (!rdata->cfile->invalidHandle || > + !cifs_reopen_file(rdata->cfile, true)) > + rc = server->ops->async_readv(rdata); > + if (rc) { > for (i = 0; i < rdata->nr_pages; i++) { > page = rdata->pages[i]; > lru_cache_add_file(page); > unlock_page(page); > page_cache_release(page); > + if (rc == -EAGAIN) > + list_add_tail(&page->lru, &tmplist); > } > kref_put(&rdata->refcount, cifs_readdata_release); > + if (rc == -EAGAIN) { > + /* Re-add pages to the page_list and retry */ > + list_splice(&tmplist, page_list); > + continue; > + } > break; > } > > -- > 1.8.1.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-cifs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index bec48f1..d627918 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -3349,6 +3349,8 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list, unsigned int expected_index; int rc; + INIT_LIST_HEAD(tmplist); + page = list_entry(page_list->prev, struct page, lru); /* @@ -3404,19 +3406,10 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, struct list_head tmplist; struct cifsFileInfo *open_file = file->private_data; struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); - unsigned int rsize = cifs_sb->rsize; + struct TCP_Server_Info *server; pid_t pid; /* - * Give up immediately if rsize is too small to read an entire page. - * The VFS will fall back to readpage. We should never reach this - * point however since we set ra_pages to 0 when the rsize is smaller - * than a cache page. - */ - if (unlikely(rsize < PAGE_CACHE_SIZE)) - return 0; - - /* * Reads as many pages as possible from fscache. Returns -ENOBUFS * immediately if the cookie is negative * @@ -3434,7 +3427,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, pid = current->tgid; rc = 0; - INIT_LIST_HEAD(&tmplist); + server = tlink_tcon(open_file->tlink)->ses->server; cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n", __func__, file, mapping, num_pages); @@ -3456,8 +3449,17 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, struct page *page, *tpage; struct cifs_readdata *rdata; - rc = readpages_get_pages(mapping, page_list, rsize, &tmplist, - &nr_pages, &offset, &bytes); + /* + * Give up immediately if rsize is too small to read an entire + * page. The VFS will fall back to readpage. We should never + * reach this point however since we set ra_pages to 0 when the + * rsize is smaller than a cache page. + */ + if (unlikely(cifs_sb->rsize < PAGE_CACHE_SIZE)) + return 0; + + rc = readpages_get_pages(mapping, page_list, cifs_sb->rsize, + &tmplist, &nr_pages, &offset, &bytes); if (rc) break; @@ -3487,15 +3489,24 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, rdata->pages[rdata->nr_pages++] = page; } - rc = cifs_retry_async_readv(rdata); - if (rc != 0) { + if (!rdata->cfile->invalidHandle || + !cifs_reopen_file(rdata->cfile, true)) + rc = server->ops->async_readv(rdata); + if (rc) { for (i = 0; i < rdata->nr_pages; i++) { page = rdata->pages[i]; lru_cache_add_file(page); unlock_page(page); page_cache_release(page); + if (rc == -EAGAIN) + list_add_tail(&page->lru, &tmplist); } kref_put(&rdata->refcount, cifs_readdata_release); + if (rc == -EAGAIN) { + /* Re-add pages to the page_list and retry */ + list_splice(&tmplist, page_list); + continue; + } break; }
If a server changes maximum buffer size for read (rsize) requests on reconnect we can fail on repeating with a big size buffer on -EAGAIN error in readpages. Fix this by checking rsize all the time before repeating requests. Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org> --- fs/cifs/file.c | 41 ++++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-)