X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fcifs%2Ffile.c;h=68ad4ca0cfa3109fa155b1c7ef9527ba3bb0aed3;hb=b22da92f2cf52b3c51dd9a45abb658b1414b0784;hp=e13592afca9c830565c420295cbc186e9f834fee;hpb=e6f194d8f6f50da6837af637b2fd839c34185f7a;p=linux-2.6 diff --git a/fs/cifs/file.c b/fs/cifs/file.c index e13592afca..68ad4ca0cf 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -467,7 +467,7 @@ reopen_error_exit: int cifs_close(struct inode *inode, struct file *file) { int rc = 0; - int xid; + int xid, timeout; struct cifs_sb_info *cifs_sb; struct cifsTconInfo *pTcon; struct cifsFileInfo *pSMBFile = @@ -485,9 +485,9 @@ int cifs_close(struct inode *inode, struct file *file) /* no sense reconnecting to close a file that is already closed */ if (pTcon->tidStatus != CifsNeedReconnect) { - int timeout = 2; + timeout = 2; while ((atomic_read(&pSMBFile->wrtPending) != 0) - && (timeout < 1000) ) { + && (timeout <= 2048)) { /* Give write a better chance to get to server ahead of the close. We do not want to add a wait_q here as it would @@ -522,12 +522,30 @@ int cifs_close(struct inode *inode, struct file *file) list_del(&pSMBFile->flist); list_del(&pSMBFile->tlist); write_unlock(&GlobalSMBSeslock); + timeout = 10; + /* We waited above to give the SMBWrite a chance to issue + on the wire (so we do not get SMBWrite returning EBADF + if writepages is racing with close. Note that writepages + does not specify a file handle, so it is possible for a file + to be opened twice, and the application close the "wrong" + file handle - in these cases we delay long enough to allow + the SMBWrite to get on the wire before the SMB Close. + We allow total wait here over 45 seconds, more than + oplock break time, and more than enough to allow any write + to complete on the server, or to time out on the client */ + while ((atomic_read(&pSMBFile->wrtPending) != 0) + && (timeout <= 50000)) { + cERROR(1, ("writes pending, delay free of handle")); + msleep(timeout); + timeout *= 8; + } kfree(pSMBFile->search_resume_name); kfree(file->private_data); file->private_data = NULL; } else rc = -EBADF; + read_lock(&GlobalSMBSeslock); if (list_empty(&(CIFS_I(inode)->openFileList))) { cFYI(1, ("closing last open instance for inode %p", inode)); /* if the file is not open we do not know if we can cache info @@ -535,6 +553,7 @@ int cifs_close(struct inode *inode, struct file *file) CIFS_I(inode)->clientCanCacheRead = FALSE; CIFS_I(inode)->clientCanCacheAll = FALSE; } + read_unlock(&GlobalSMBSeslock); if ((rc == 0) && CIFS_I(inode)->write_behind_rc) rc = CIFS_I(inode)->write_behind_rc; FreeXid(xid); @@ -767,7 +786,8 @@ int cifs_lock(struct file *file, int cmd, struct file_lock *pfLock) mutex_lock(&fid->lock_mutex); list_for_each_entry_safe(li, tmp, &fid->llist, llist) { if (pfLock->fl_start <= li->offset && - length >= li->length) { + (pfLock->fl_start + length) >= + (li->offset + li->length)) { stored_rc = CIFSSMBLock(xid, pTcon, netfid, li->length, li->offset, @@ -1006,6 +1026,37 @@ static ssize_t cifs_write(struct file *file, const char *write_data, return total_written; } +#ifdef CONFIG_CIFS_EXPERIMENTAL +struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode) +{ + struct cifsFileInfo *open_file = NULL; + + read_lock(&GlobalSMBSeslock); + /* we could simply get the first_list_entry since write-only entries + are always at the end of the list but since the first entry might + have a close pending, we go through the whole list */ + list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { + if (open_file->closePend) + continue; + if (open_file->pfile && ((open_file->pfile->f_flags & O_RDWR) || + (open_file->pfile->f_flags & O_RDONLY))) { + if (!open_file->invalidHandle) { + /* found a good file */ + /* lock it so it will not be closed on us */ + atomic_inc(&open_file->wrtPending); + read_unlock(&GlobalSMBSeslock); + return open_file; + } /* else might as well continue, and look for + another, or simply have the caller reopen it + again rather than trying to fix this handle */ + } else /* write only file */ + break; /* write only files are last so must be done */ + } + read_unlock(&GlobalSMBSeslock); + return NULL; +} +#endif + struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode) { struct cifsFileInfo *open_file; @@ -1022,6 +1073,7 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode) } read_lock(&GlobalSMBSeslock); +refind_writable: list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { if (open_file->closePend) continue; @@ -1029,24 +1081,49 @@ struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode) ((open_file->pfile->f_flags & O_RDWR) || (open_file->pfile->f_flags & O_WRONLY))) { atomic_inc(&open_file->wrtPending); + + if (!open_file->invalidHandle) { + /* found a good writable file */ + read_unlock(&GlobalSMBSeslock); + return open_file; + } + read_unlock(&GlobalSMBSeslock); - if ((open_file->invalidHandle) && - (!open_file->closePend) /* BB fixme -since the second clause can not be true remove it BB */) { - rc = cifs_reopen_file(open_file->pfile, FALSE); - /* if it fails, try another handle - might be */ - /* dangerous to hold up writepages with retry */ - if (rc) { - cFYI(1, - ("failed on reopen file in wp")); + /* Had to unlock since following call can block */ + rc = cifs_reopen_file(open_file->pfile, FALSE); + if (!rc) { + if (!open_file->closePend) + return open_file; + else { /* start over in case this was deleted */ + /* since the list could be modified */ read_lock(&GlobalSMBSeslock); - /* can not use this handle, no write - pending on this one after all */ - atomic_dec - (&open_file->wrtPending); - continue; + atomic_dec(&open_file->wrtPending); + goto refind_writable; } } - return open_file; + + /* if it fails, try another handle if possible - + (we can not do this if closePending since + loop could be modified - in which case we + have to start at the beginning of the list + again. Note that it would be bad + to hold up writepages here (rather than + in caller) with continuous retries */ + cFYI(1, ("wp failed on reopen file")); + read_lock(&GlobalSMBSeslock); + /* can not use this handle, no write + pending on this one after all */ + atomic_dec(&open_file->wrtPending); + + if (open_file->closePend) /* list could have changed */ + goto refind_writable; + /* else we simply continue to the next entry. Thus + we do not loop on reopen errors. If we + can not reopen the file, for example if we + reconnected to a server with another client + racing to delete or lock the file we would not + make progress if we restarted before the beginning + of the loop here. */ } } read_unlock(&GlobalSMBSeslock); @@ -1709,7 +1786,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, struct page *page; struct cifs_sb_info *cifs_sb; struct cifsTconInfo *pTcon; - int bytes_read = 0; + unsigned int bytes_read = 0; unsigned int read_size, i; char *smb_read_data = NULL; struct smb_com_read_rsp *pSMBr; @@ -1803,7 +1880,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, i += bytes_read >> PAGE_CACHE_SHIFT; cifs_stats_bytes_read(pTcon, bytes_read); - if ((int)(bytes_read & PAGE_CACHE_MASK) != bytes_read) { + if ((bytes_read & PAGE_CACHE_MASK) != bytes_read) { i++; /* account for partial page */ /* server copy of file can have smaller size @@ -1904,6 +1981,25 @@ static int cifs_readpage(struct file *file, struct page *page) return rc; } +static int is_inode_writable(struct cifsInodeInfo *cifs_inode) +{ + struct cifsFileInfo *open_file; + + read_lock(&GlobalSMBSeslock); + list_for_each_entry(open_file, &cifs_inode->openFileList, flist) { + if (open_file->closePend) + continue; + if (open_file->pfile && + ((open_file->pfile->f_flags & O_RDWR) || + (open_file->pfile->f_flags & O_WRONLY))) { + read_unlock(&GlobalSMBSeslock); + return 1; + } + } + read_unlock(&GlobalSMBSeslock); + return 0; +} + /* We do not want to update the file size from server for inodes open for write - to avoid races with writepage extending the file - in the future we could consider allowing @@ -1912,19 +2008,13 @@ static int cifs_readpage(struct file *file, struct page *page) page caching in the current Linux kernel design */ int is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file) { - struct cifsFileInfo *open_file = NULL; - - if (cifsInode) - open_file = find_writable_file(cifsInode); + if (!cifsInode) + return 1; - if (open_file) { + if (is_inode_writable(cifsInode)) { + /* This inode is open for write at least once */ struct cifs_sb_info *cifs_sb; - /* there is not actually a write pending so let - this handle go free and allow it to - be closable if needed */ - atomic_dec(&open_file->wrtPending); - cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb); if ( cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO ) { /* since no page cache to corrupt on directio