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CIFS: Return error code when getting file handle for writeback 

Now we just return NULL cifsFileInfo pointer in cases we didn't find
or couldn't reopen a file. This hides errors from cifs_reopen_file()
especially retryable errors which should be handled appropriately.
Create new cifs_get_writable_file() routine that returns error codes
from cifs_reopen_file() and use it in the writeback codepath.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Pavel Shilovsky 2019-01-29 12:15:11 -08:00 committed by Steve French
parent c4b8f657d5
commit fe768d51c8
3 changed files with 70 additions and 32 deletions
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3
fs/cifs/cifsproto.h
View File

@ -134,6 +134,9 @@ extern bool is_size_safe_to_change(struct cifsInodeInfo *, __u64 eof);
extern void cifs_update_eof(struct cifsInodeInfo *cifsi, loff_t offset,
unsigned int bytes_written);
extern struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *, bool);
extern int cifs_get_writable_file(struct cifsInodeInfo *cifs_inode,
bool fsuid_only,
struct cifsFileInfo **ret_file);
extern struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *, bool);
extern unsigned int smbCalcSize(void *buf, struct TCP_Server_Info *server);
extern int decode_negTokenInit(unsigned char *security_blob, int length,

9
fs/cifs/cifssmb.c
View File

@ -2126,10 +2126,13 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
wdata2->tailsz = tailsz;
wdata2->bytes = cur_len;
wdata2->cfile = find_writable_file(CIFS_I(inode), false);
rc = cifs_get_writable_file(CIFS_I(inode), false,
&wdata2->cfile);
if (!wdata2->cfile) {
cifs_dbg(VFS, "No writable handle to retry writepages\n");
rc = -EBADF;
cifs_dbg(VFS, "No writable handle to retry writepages rc=%d\n",
rc);
if (!is_retryable_error(rc))
rc = -EBADF;
} else {
wdata2->pid = wdata2->cfile->pid;
rc = server->ops->async_writev(wdata2,

90
fs/cifs/file.c
View File

@ -1842,24 +1842,30 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
return NULL;
}
struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
bool fsuid_only)
/* Return -EBADF if no handle is found and general rc otherwise */
int
cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only,
struct cifsFileInfo **ret_file)
{
struct cifsFileInfo *open_file, *inv_file = NULL;
struct cifs_sb_info *cifs_sb;
struct cifs_tcon *tcon;
bool any_available = false;
int rc;
int rc = -EBADF;
unsigned int refind = 0;
/* Having a null inode here (because mapping->host was set to zero by
the VFS or MM) should not happen but we had reports of on oops (due to
it being zero) during stress testcases so we need to check for it */
*ret_file = NULL;
/*
* Having a null inode here (because mapping->host was set to zero by
* the VFS or MM) should not happen but we had reports of on oops (due
* to it being zero) during stress testcases so we need to check for it
*/
if (cifs_inode == NULL) {
cifs_dbg(VFS, "Null inode passed to cifs_writeable_file\n");
dump_stack();
return NULL;
return rc;
}
cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
@ -1873,7 +1879,7 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
refind_writable:
if (refind > MAX_REOPEN_ATT) {
spin_unlock(&tcon->open_file_lock);
return NULL;
return rc;
}
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
if (!any_available && open_file->pid != current->tgid)
@ -1885,7 +1891,8 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
/* found a good writable file */
cifsFileInfo_get(open_file);
spin_unlock(&tcon->open_file_lock);
return open_file;
*ret_file = open_file;
return 0;
} else {
if (!inv_file)
inv_file = open_file;
@ -1907,22 +1914,35 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode,
if (inv_file) {
rc = cifs_reopen_file(inv_file, false);
if (!rc)
return inv_file;
else {
spin_lock(&tcon->open_file_lock);
list_move_tail(&inv_file->flist,
&cifs_inode->openFileList);
spin_unlock(&tcon->open_file_lock);
cifsFileInfo_put(inv_file);
++refind;
inv_file = NULL;
spin_lock(&tcon->open_file_lock);
goto refind_writable;
if (!rc) {
*ret_file = inv_file;
return 0;
}
spin_lock(&tcon->open_file_lock);
list_move_tail(&inv_file->flist, &cifs_inode->openFileList);
spin_unlock(&tcon->open_file_lock);
cifsFileInfo_put(inv_file);
++refind;
inv_file = NULL;
spin_lock(&tcon->open_file_lock);
goto refind_writable;
}
return NULL;
return rc;
}
struct cifsFileInfo *
find_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only)
{
struct cifsFileInfo *cfile;
int rc;
rc = cifs_get_writable_file(cifs_inode, fsuid_only, &cfile);
if (rc)
cifs_dbg(FYI, "couldn't find writable handle rc=%d", rc);
return cfile;
}
static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
@ -1959,8 +1979,8 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
if (mapping->host->i_size - offset < (loff_t)to)
to = (unsigned)(mapping->host->i_size - offset);
open_file = find_writable_file(CIFS_I(mapping->host), false);
if (open_file) {
rc = cifs_get_writable_file(CIFS_I(mapping->host), false, &open_file);
if (!rc) {
bytes_written = cifs_write(open_file, open_file->pid,
write_data, to - from, &offset);
cifsFileInfo_put(open_file);
@ -1970,9 +1990,12 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
rc = 0;
else if (bytes_written < 0)
rc = bytes_written;
else
rc = -EFAULT;
} else {
cifs_dbg(FYI, "No writeable filehandles for inode\n");
rc = -EIO;
cifs_dbg(FYI, "No writable handle for write page rc=%d\n", rc);
if (!is_retryable_error(rc))
rc = -EIO;
}
kunmap(page);
@ -2144,11 +2167,16 @@ static int cifs_writepages(struct address_space *mapping,
pgoff_t next = 0, tofind, saved_index = index;
struct cifs_credits credits_on_stack;
struct cifs_credits *credits = &credits_on_stack;
int get_file_rc = 0;
if (cfile)
cifsFileInfo_put(cfile);
cfile = find_writable_file(CIFS_I(inode), false);
rc = cifs_get_writable_file(CIFS_I(inode), false, &cfile);
/* in case of an error store it to return later */
if (rc)
get_file_rc = rc;
rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
&wsize, credits);
@ -2189,8 +2217,12 @@ static int cifs_writepages(struct address_space *mapping,
cfile = NULL;
if (!wdata->cfile) {
cifs_dbg(VFS, "No writable handle in writepages\n");
rc = -EBADF;
cifs_dbg(VFS, "No writable handle in writepages rc=%d\n",
get_file_rc);
if (is_retryable_error(get_file_rc))
rc = get_file_rc;
else
rc = -EBADF;
} else
rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);