diff options
| author | Andrew Morton <akpm@osdl.org> | 2006-04-21 01:51:36 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-05-01 12:03:43 -0700 |
| commit | 692c0509fd0719406f8f781d9a9f2e19aa6b7c0a (patch) | |
| tree | 947a3bfc5610fd194785f9e081ec6439c3972deb /include | |
| parent | ebea8457d4b94864a818ae3e6a95655602244935 (diff) | |
[PATCH] Simplify proc/devices and fix early termination regression
Repair /proc/devices early-termination regression.
2.6.16 broke /proc/devices. An application often gets an
EOF before the end of data is reached, if that application
uses a series of short read(2)s to access the data. I have
used read buffers of varying sizes with varying degrees
of unsuccess (larger sizes get further into the data than
smaller sizes, following a simple pattern). It appears
that the only safe way to get the data is to use a single
read buffer larger than all the data in /proc/devices.
The following example demonstates the problem:
# dd if=/proc/devices bs=1
Character devices:
1 mem
27+0 records in
27+0 records out
This patch is a backport of the fix recently accepted to
Linus's tree:
commit 68eef3b4791572ecb70249c7fb145bb3742dd899
[PATCH] Simplify proc/devices and fix early termination regression
It replaces the complex, state-machine algorithm introduced
in 2.6.16 with a simple algorithm, modeled on the implementation
of /proc/interrupts.
[akpm@osdl.org: cleanups, simplifications]
Signed-off-by: Joe Korty <joe.korty@ccur.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/fs.h | 15 |
1 files changed, 4 insertions, 11 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 128d0082522..872042fd27e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1383,6 +1383,7 @@ extern int bd_claim(struct block_device *, void *); extern void bd_release(struct block_device *); /* fs/char_dev.c */ +#define CHRDEV_MAJOR_HASH_SIZE 255 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *); extern int register_chrdev_region(dev_t, unsigned, const char *); extern int register_chrdev(unsigned int, const char *, @@ -1390,25 +1391,17 @@ extern int register_chrdev(unsigned int, const char *, extern int unregister_chrdev(unsigned int, const char *); extern void unregister_chrdev_region(dev_t, unsigned); extern int chrdev_open(struct inode *, struct file *); -extern int get_chrdev_list(char *); -extern void *acquire_chrdev_list(void); -extern int count_chrdev_list(void); -extern void *get_next_chrdev(void *); -extern int get_chrdev_info(void *, int *, char **); -extern void release_chrdev_list(void *); +extern void chrdev_show(struct seq_file *,off_t); /* fs/block_dev.c */ +#define BLKDEV_MAJOR_HASH_SIZE 255 #define BDEVNAME_SIZE 32 /* Largest string for a blockdev identifier */ extern const char *__bdevname(dev_t, char *buffer); extern const char *bdevname(struct block_device *bdev, char *buffer); extern struct block_device *lookup_bdev(const char *); extern struct block_device *open_bdev_excl(const char *, int, void *); extern void close_bdev_excl(struct block_device *); -extern void *acquire_blkdev_list(void); -extern int count_blkdev_list(void); -extern void *get_next_blkdev(void *); -extern int get_blkdev_info(void *, int *, char **); -extern void release_blkdev_list(void *); +extern void blkdev_show(struct seq_file *,off_t); extern void init_special_inode(struct inode *, umode_t, dev_t); |