[patch] inotify 0.22 for 2.6.12-rc1-mm4
On Mon, 2005-04-04 at 16:02 -0400, Robert Love wrote:
Greetings, Mr Morton.
> Below, find inotify 0.22, against 2.6.12-rc1.
>
> This release introduces a conversion in our primary locking from
> spinlocks to semaphores. Semaphores are a more natural fit for our
> code, which synchronizes with user-space, thus we clean up a bit of code
> with a net reduction of 63 lines. Also, I was able to remove the
> GFP_ATOMIC allocation.
>
> I did this as a bit of an experiment, not to fix any specific problem,
> and I now think it is the right way to go.
>
> This release also fixes a small bug in the coalescing code, which could
> of mistakenly dropped a move event. We now verify that the cookies
> match before coalescing.
And a patch for 2.6.12-rc1-mm4.
Robert Love
inotify!
inotify is intended to correct the deficiencies of dnotify, particularly
its inability to scale and its terrible user interface:
* dnotify requires the opening of one fd per each directory
that you intend to watch. This quickly results in too many
open files and pins removable media, preventing unmount.
* dnotify is directory-based. You only learn about changes to
directories. Sure, a change to a file in a directory affects
the directory, but you are then forced to keep a cache of
stat structures.
* dnotify's interface to user-space is awful. Signals?
inotify provides a more usable, simple, powerful solution to file change
notification:
* inotify's interface is a device node, not SIGIO. You open a
single fd to the device node, which is select()-able.
* inotify has an event that says "the filesystem that the item
you were watching is on was unmounted."
* inotify can watch directories or files.
Inotify is currently used by Beagle (a desktop search infrastructure)
and Gamin (a FAM replacement).
Signed-off-by: Robert Love <[EMAIL PROTECTED]>
Documentation/filesystems/inotify.txt | 81 ++
fs/Kconfig| 13
fs/Makefile |1
fs/attr.c | 33 -
fs/compat.c | 12
fs/file_table.c |3
fs/inode.c|6
fs/inotify.c | 979 ++
fs/namei.c| 30 -
fs/open.c |6
fs/read_write.c | 15
include/linux/fs.h|6
include/linux/fsnotify.h | 228 +++
include/linux/inotify.h | 113 +++
include/linux/sched.h |4
kernel/user.c |4
16 files changed, 1478 insertions(+), 56 deletions(-)
diff -urN linux-2.6.12-rc1-mm4/Documentation/filesystems/inotify.txt
linux/Documentation/filesystems/inotify.txt
--- linux-2.6.12-rc1-mm4/Documentation/filesystems/inotify.txt 1969-12-31
19:00:00.0 -0500
+++ linux/Documentation/filesystems/inotify.txt 2005-04-04 13:32:02.0
-0400
@@ -0,0 +1,81 @@
+ inotify
+a powerful yet simple file change notification system
+
+
+
+Document started 15 Mar 2005 by Robert Love <[EMAIL PROTECTED]>
+
+(i) User Interface
+
+Inotify is controlled by a device node, /dev/inotify. If you do not use udev,
+this device may need to be created manually. First step, open it
+
+ int dev_fd = open ("/dev/inotify", O_RDONLY);
+
+Change events are managed by "watches". A watch is an (object,mask) pair where
+the object is a file or directory and the mask is a bitmask of one or more
+inotify events that the application wishes to receive. See
+for valid events. A watch is referenced by a watch descriptor, or wd.
+
+Watches are added via a file descriptor.
+
+Watches on a directory will return events on any files inside of the directory.
+
+Adding a watch is simple,
+
+ /* 'wd' represents the watch on fd with mask */
+ struct inotify_request req = { fd, mask };
+ int wd = ioctl (dev_fd, INOTIFY_WATCH, );
+
+You can add a large number of files via something like
+
+ for each file to watch {
+ struct inotify_request req;
+ int file_fd;
+
+ file_fd = open (file, O_RDONLY);
+ if (fd < 0) {
+ perror ("open");
+ break;
+ }
+
+ req.fd = file_fd;
+ req.mask = mask;
+
+ wd = ioctl (dev_fd, INOTIFY_WATCH, );
+
+ close (fd);
+ }
+
+You can update an existing watch in the same manner, by passing in a new mask.
+
+An existing watch is removed via the INOTIFY_IGNORE ioctl, for example
+
+ ioctl (dev_fd, INOTIFY_IGNORE, wd);
+
+Events are provided in the form of an inotify_event structure that is read(2)
+from /dev/inotify. The filename is of dynamic
[patch] inotify 0.22 for 2.6.12-rc1-mm4
On Mon, 2005-04-04 at 16:02 -0400, Robert Love wrote:
Greetings, Mr Morton.
Below, find inotify 0.22, against 2.6.12-rc1.
This release introduces a conversion in our primary locking from
spinlocks to semaphores. Semaphores are a more natural fit for our
code, which synchronizes with user-space, thus we clean up a bit of code
with a net reduction of 63 lines. Also, I was able to remove the
GFP_ATOMIC allocation.
I did this as a bit of an experiment, not to fix any specific problem,
and I now think it is the right way to go.
This release also fixes a small bug in the coalescing code, which could
of mistakenly dropped a move event. We now verify that the cookies
match before coalescing.
And a patch for 2.6.12-rc1-mm4.
Robert Love
inotify!
inotify is intended to correct the deficiencies of dnotify, particularly
its inability to scale and its terrible user interface:
* dnotify requires the opening of one fd per each directory
that you intend to watch. This quickly results in too many
open files and pins removable media, preventing unmount.
* dnotify is directory-based. You only learn about changes to
directories. Sure, a change to a file in a directory affects
the directory, but you are then forced to keep a cache of
stat structures.
* dnotify's interface to user-space is awful. Signals?
inotify provides a more usable, simple, powerful solution to file change
notification:
* inotify's interface is a device node, not SIGIO. You open a
single fd to the device node, which is select()-able.
* inotify has an event that says the filesystem that the item
you were watching is on was unmounted.
* inotify can watch directories or files.
Inotify is currently used by Beagle (a desktop search infrastructure)
and Gamin (a FAM replacement).
Signed-off-by: Robert Love [EMAIL PROTECTED]
Documentation/filesystems/inotify.txt | 81 ++
fs/Kconfig| 13
fs/Makefile |1
fs/attr.c | 33 -
fs/compat.c | 12
fs/file_table.c |3
fs/inode.c|6
fs/inotify.c | 979 ++
fs/namei.c| 30 -
fs/open.c |6
fs/read_write.c | 15
include/linux/fs.h|6
include/linux/fsnotify.h | 228 +++
include/linux/inotify.h | 113 +++
include/linux/sched.h |4
kernel/user.c |4
16 files changed, 1478 insertions(+), 56 deletions(-)
diff -urN linux-2.6.12-rc1-mm4/Documentation/filesystems/inotify.txt
linux/Documentation/filesystems/inotify.txt
--- linux-2.6.12-rc1-mm4/Documentation/filesystems/inotify.txt 1969-12-31
19:00:00.0 -0500
+++ linux/Documentation/filesystems/inotify.txt 2005-04-04 13:32:02.0
-0400
@@ -0,0 +1,81 @@
+ inotify
+a powerful yet simple file change notification system
+
+
+
+Document started 15 Mar 2005 by Robert Love [EMAIL PROTECTED]
+
+(i) User Interface
+
+Inotify is controlled by a device node, /dev/inotify. If you do not use udev,
+this device may need to be created manually. First step, open it
+
+ int dev_fd = open (/dev/inotify, O_RDONLY);
+
+Change events are managed by watches. A watch is an (object,mask) pair where
+the object is a file or directory and the mask is a bitmask of one or more
+inotify events that the application wishes to receive. See linux/inotify.h
+for valid events. A watch is referenced by a watch descriptor, or wd.
+
+Watches are added via a file descriptor.
+
+Watches on a directory will return events on any files inside of the directory.
+
+Adding a watch is simple,
+
+ /* 'wd' represents the watch on fd with mask */
+ struct inotify_request req = { fd, mask };
+ int wd = ioctl (dev_fd, INOTIFY_WATCH, req);
+
+You can add a large number of files via something like
+
+ for each file to watch {
+ struct inotify_request req;
+ int file_fd;
+
+ file_fd = open (file, O_RDONLY);
+ if (fd 0) {
+ perror (open);
+ break;
+ }
+
+ req.fd = file_fd;
+ req.mask = mask;
+
+ wd = ioctl (dev_fd, INOTIFY_WATCH, req);
+
+ close (fd);
+ }
+
+You can update an existing watch in the same manner, by passing in a new mask.
+
+An existing watch is removed via the INOTIFY_IGNORE ioctl, for example
+
+ ioctl (dev_fd, INOTIFY_IGNORE, wd);
+
+Events are provided in the form of an inotify_event structure that is read(2)
+from /dev/inotify. The filename is of dynamic
