diff options
Diffstat (limited to 'nuttx/fs/nxffs/nxffs_open.c')
-rw-r--r-- | nuttx/fs/nxffs/nxffs_open.c | 65 |
1 files changed, 62 insertions, 3 deletions
diff --git a/nuttx/fs/nxffs/nxffs_open.c b/nuttx/fs/nxffs/nxffs_open.c index eb7817c57..9fa4ef2e0 100644 --- a/nuttx/fs/nxffs/nxffs_open.c +++ b/nuttx/fs/nxffs/nxffs_open.c @@ -1,7 +1,7 @@ /**************************************************************************** * fs/nxffs/nxffs_open.c * - * Copyright (C) 2011 Gregory Nutt. All rights reserved. + * Copyright (C) 2011, 2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt <gnutt@nuttx.org> * * References: Linux/Documentation/filesystems/romfs.txt @@ -1023,7 +1023,7 @@ int nxffs_open(FAR struct file *filep, FAR const char *relpath, #endif /* Limitation: A file must be opened for reading or writing, but not both. - * There is no general for extending the size of of a file. Extending the + * There is no general way of extending the size of a file. Extending the * file size of possible if the file to be extended is the last in the * sequence on FLASH, but since that case is not the general case, no file * extension is supported. @@ -1059,6 +1059,64 @@ int nxffs_open(FAR struct file *filep, FAR const char *relpath, } /**************************************************************************** + * Name: binfs_dup + * + * Description: + * Duplicate open file data in the new file structure. + * + ****************************************************************************/ + +int nxffs_dup(FAR const struct file *oldp, FAR struct file *newp) +{ +#ifdef CONFIG_DEBUG + FAR struct nxffs_volume_s *volume; +#endif + FAR struct nxffs_ofile_s *ofile; + + fvdbg("Dup %p->%p\n", oldp, newp); + + /* Sanity checks */ + +#ifdef CONFIG_DEBUG + DEBUGASSERT(oldp->f_priv == NULL && oldp->f_inode != NULL); + + /* Get the mountpoint private data from the NuttX inode reference in the + * file structure + */ + + volume = (FAR struct nxffs_volume_s*)oldp->f_inode->i_private; + DEBUGASSERT(volume != NULL); +#endif + + /* Recover the open file state from the struct file instance */ + + ofile = (FAR struct nxffs_ofile_s *)oldp->f_priv; + + /* I do not think we need exclusive access to the volume to do this. + * The volume exclsem protects the open file list and, hence, would + * assure that the ofile is stable. However, it is assumed that the + * caller holds a value file descriptor associated with this ofile, + * so it should be stable throughout the life of this function. + */ + + /* Limitations: I do not think we have to be concerned about the + * usual NXFFS file limitations here: dup'ing cannot resulting + * in mixed reading and writing to the same file, or multiple + * writer to different file. + * + * I notice that nxffs_wropen will prohibit multiple opens for + * writing. But I do not thing that dup'ing a file already opened + * for writing suffers from any of these issues. + */ + + /* Just increment the reference count on the ofile */ + + ofile->crefs++; + newp->f_priv = (FAR void *)ofile; + return OK; +} + +/**************************************************************************** * Name: nxffs_close * * Description: @@ -1130,9 +1188,10 @@ int nxffs_close(FAR struct file *filep) ofile->crefs--; } - filep->f_priv = NULL; + filep->f_priv = NULL; sem_post(&volume->exclsem); + errout: return ret; } |