i2p/haiku-beta6
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

VFS: Slight rework of the FD disconnect feature.

Browse Source 
* This should fix ticket #4157, although I probably have missed
  something.
* In any case, it no longer messes with the ref counts of the
  file descriptor, and the race condition in put_fd() should be
  gone.
* It's still rather messy all in all.
This commit is contained in:
Axel Dörfler
2015-09-11 17:25:01 +02:00
parent 6adf7a0c75
commit eb62d3337b
2 changed files with 23 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/system/kernel/fs/fd.cpp
+19 -25
View File
@@ -1,6 +1,6 @@
/* /*
* Copyright 2009-2011, Ingo Weinhold, [email protected]. * Copyright 2009-2011, Ingo Weinhold, [email protected].
* Copyright 2002-2010, Axel Dörfler, [email protected]. * Copyright 2002-2015, Axel Dörfler, [email protected].
* Distributed under the terms of the MIT License. * Distributed under the terms of the MIT License.
*/ */
@@ -224,13 +224,11 @@ put_fd(struct file_descriptor* descriptor)
descriptor->ops->fd_free(descriptor); descriptor->ops->fd_free(descriptor);
// prevent this descriptor from being closed/freed again // prevent this descriptor from being closed/freed again
descriptor->open_count = -1;
descriptor->ref_count = -1;
descriptor->ops = NULL; descriptor->ops = NULL;
descriptor->u.vnode = NULL; descriptor->u.vnode = NULL;
// the file descriptor is kept intact, so that it's not // the file descriptor is kept intact, so that it's not
// reused until someone explicetly closes it // reused until someone explicitly closes it
} }
} }
@@ -295,14 +293,9 @@ get_fd_locked(struct io_context* context, int fd)
struct file_descriptor* descriptor = context->fds[fd]; struct file_descriptor* descriptor = context->fds[fd];
if (descriptor != NULL) { if (descriptor != NULL) {
// Disconnected descriptors cannot be accessed anymore
if (descriptor->open_mode & O_DISCONNECTED)
descriptor = NULL;
else {
TFD(GetFD(context, fd, descriptor)); TFD(GetFD(context, fd, descriptor));
inc_fd_ref_count(descriptor); inc_fd_ref_count(descriptor);
} }
}
return descriptor; return descriptor;
} }
@@ -323,7 +316,7 @@ get_open_fd(struct io_context* context, int fd)
MutexLocker _(context->io_mutex); MutexLocker _(context->io_mutex);
file_descriptor* descriptor = get_fd_locked(context, fd); file_descriptor* descriptor = get_fd_locked(context, fd);
if (descriptor == NULL) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return NULL; return NULL;
atomic_add(&descriptor->open_count, 1); atomic_add(&descriptor->open_count, 1);
@@ -427,7 +420,8 @@ dup2_fd(int oldfd, int newfd, bool kernel)
// the table size could be changed) // the table size could be changed)
if ((uint32)oldfd >= context->table_size if ((uint32)oldfd >= context->table_size
|| (uint32)newfd >= context->table_size || (uint32)newfd >= context->table_size
|| context->fds[oldfd] == NULL) { || context->fds[oldfd] == NULL
|| (context->fds[oldfd]->open_mode & O_DISCONNECTED) != 0) {
mutex_unlock(&context->io_mutex); mutex_unlock(&context->io_mutex);
return B_FILE_ERROR; return B_FILE_ERROR;
} }
@@ -508,10 +502,10 @@ fd_ioctl(bool kernelFD, int fd, uint32 op, void* buffer, size_t length)
int status; int status;
descriptor = get_fd(get_current_io_context(kernelFD), fd); descriptor = get_fd(get_current_io_context(kernelFD), fd);
if (descriptor == NULL) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
if (descriptor->ops->fd_ioctl) if (descriptor->ops->fd_ioctl != NULL)
status = descriptor->ops->fd_ioctl(descriptor, op, buffer, length); status = descriptor->ops->fd_ioctl(descriptor, op, buffer, length);
else else
status = B_DEV_INVALID_IOCTL; status = B_DEV_INVALID_IOCTL;
@@ -567,7 +561,7 @@ select_fd(int32 fd, struct select_info* info, bool kernel)
MutexLocker locker(context->io_mutex); MutexLocker locker(context->io_mutex);
struct file_descriptor* descriptor = fdGetter.SetTo(context, fd, true); struct file_descriptor* descriptor = fdGetter.SetTo(context, fd, true);
if (descriptor == NULL) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
uint16 eventsToSelect = info->selected_events & ~B_EVENT_INVALID; uint16 eventsToSelect = info->selected_events & ~B_EVENT_INVALID;
@@ -685,7 +679,7 @@ fd_is_valid(int fd, bool kernel)
{ {
struct file_descriptor* descriptor struct file_descriptor* descriptor
= get_fd(get_current_io_context(kernel), fd); = get_fd(get_current_io_context(kernel), fd);
if (descriptor == NULL) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return false; return false;
put_fd(descriptor); put_fd(descriptor);
@@ -726,7 +720,7 @@ common_user_io(int fd, off_t pos, void* buffer, size_t length, bool write)
FDGetter fdGetter; FDGetter fdGetter;
struct file_descriptor* descriptor = fdGetter.SetTo(fd, false); struct file_descriptor* descriptor = fdGetter.SetTo(fd, false);
if (!descriptor) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
if (write ? (descriptor->open_mode & O_RWMASK) == O_RDONLY if (write ? (descriptor->open_mode & O_RWMASK) == O_RDONLY
@@ -778,7 +772,7 @@ common_user_vector_io(int fd, off_t pos, const iovec* userVecs, size_t count,
FDGetter fdGetter; FDGetter fdGetter;
struct file_descriptor* descriptor = fdGetter.SetTo(fd, false); struct file_descriptor* descriptor = fdGetter.SetTo(fd, false);
if (!descriptor) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
if (write ? (descriptor->open_mode & O_RWMASK) == O_RDONLY if (write ? (descriptor->open_mode & O_RWMASK) == O_RDONLY
@@ -891,12 +885,12 @@ _user_seek(int fd, off_t pos, int seekType)
struct file_descriptor* descriptor; struct file_descriptor* descriptor;
descriptor = get_fd(get_current_io_context(false), fd); descriptor = get_fd(get_current_io_context(false), fd);
if (!descriptor) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
TRACE(("user_seek(descriptor = %p)\n", descriptor)); TRACE(("user_seek(descriptor = %p)\n", descriptor));
if (descriptor->ops->fd_seek) if (descriptor->ops->fd_seek != NULL)
pos = descriptor->ops->fd_seek(descriptor, pos, seekType); pos = descriptor->ops->fd_seek(descriptor, pos, seekType);
else else
pos = ESPIPE; pos = ESPIPE;
@@ -937,7 +931,7 @@ _user_read_dir(int fd, struct dirent* userBuffer, size_t bufferSize,
io_context* ioContext = get_current_io_context(false); io_context* ioContext = get_current_io_context(false);
FDGetter fdGetter; FDGetter fdGetter;
struct file_descriptor* descriptor = fdGetter.SetTo(ioContext, fd, false); struct file_descriptor* descriptor = fdGetter.SetTo(ioContext, fd, false);
if (descriptor == NULL) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
if (descriptor->ops->fd_read_dir == NULL) if (descriptor->ops->fd_read_dir == NULL)
@@ -983,10 +977,10 @@ _user_rewind_dir(int fd)
TRACE(("user_rewind_dir(fd = %d)\n", fd)); TRACE(("user_rewind_dir(fd = %d)\n", fd));
descriptor = get_fd(get_current_io_context(false), fd); descriptor = get_fd(get_current_io_context(false), fd);
if (descriptor == NULL) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
if (descriptor->ops->fd_rewind_dir) if (descriptor->ops->fd_rewind_dir != NULL)
status = descriptor->ops->fd_rewind_dir(descriptor); status = descriptor->ops->fd_rewind_dir(descriptor);
else else
status = B_UNSUPPORTED; status = B_UNSUPPORTED;
@@ -1124,7 +1118,7 @@ _kern_write(int fd, off_t pos, const void* buffer, size_t length)
FDGetter fdGetter; FDGetter fdGetter;
struct file_descriptor* descriptor = fdGetter.SetTo(fd, true); struct file_descriptor* descriptor = fdGetter.SetTo(fd, true);
if (descriptor == NULL) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
if ((descriptor->open_mode & O_RWMASK) == O_RDONLY) if ((descriptor->open_mode & O_RWMASK) == O_RDONLY)
return B_FILE_ERROR; return B_FILE_ERROR;
@@ -1252,7 +1246,7 @@ _kern_read_dir(int fd, struct dirent* buffer, size_t bufferSize,
struct io_context* ioContext = get_current_io_context(true); struct io_context* ioContext = get_current_io_context(true);
descriptor = get_fd(ioContext, fd); descriptor = get_fd(ioContext, fd);
if (descriptor == NULL) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
if (descriptor->ops->fd_read_dir) { if (descriptor->ops->fd_read_dir) {
@@ -1278,7 +1272,7 @@ _kern_rewind_dir(int fd)
TRACE(("sys_rewind_dir(fd = %d)\n",fd)); TRACE(("sys_rewind_dir(fd = %d)\n",fd));
descriptor = get_fd(get_current_io_context(true), fd); descriptor = get_fd(get_current_io_context(true), fd);
if (descriptor == NULL) if (descriptor == NULL || (descriptor->open_mode & O_DISCONNECTED) != 0)
return B_FILE_ERROR; return B_FILE_ERROR;
if (descriptor->ops->fd_rewind_dir) if (descriptor->ops->fd_rewind_dir)
src/system/kernel/fs/vfs.cpp
+2 -1
View File
@@ -4864,7 +4864,8 @@ vfs_new_io_context(io_context* parentContext, bool purgeCloseOnExec)
for (i = 0; i < tableSize; i++) { for (i = 0; i < tableSize; i++) {
struct file_descriptor* descriptor = parentContext->fds[i]; struct file_descriptor* descriptor = parentContext->fds[i];
if (descriptor != NULL) { if (descriptor != NULL
&& (descriptor->open_mode & O_DISCONNECTED) == 0) {
bool closeOnExec = fd_close_on_exec(parentContext, i); bool closeOnExec = fd_close_on_exec(parentContext, i);
if (closeOnExec && purgeCloseOnExec) if (closeOnExec && purgeCloseOnExec)
continue; continue;