kernel/linux.git/drivers/block/floppy.c, branch linux-2.6.22.y

Off by one in floppy.c

2007-05-24T03:14:15+00:00

Another coverity patch i forgot to resend, original thread here http://marc.info/?l=linux-kernel&m=115144559823592&w=2 In case drive == N_DRIVE, we get one past the drive_params array. Signed-off-by: Eric Sesterhenn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

floppy: handle device_create_file() failure while init

2007-05-08T18:15:02+00:00

This patch kills the "ignoring return value of 'device_create_file'" warning message. Signed-off-by: Monakhov Dmitriy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Fix build errors if bitop functions are do {} while macros

2007-02-21T01:10:12+00:00

If one of clear_bit, change_bit or set_bit is defined as a do { } while (0) function usage of these functions in parenthesis like (foo_bit(23, &var)) while be expaned to something like (do { ... } while (0)}). resulting in a build error. This patch removes the useless parenthesis. Signed-off-by: Ralf Baechle Cc: Trond Myklebust Cc: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

WorkStruct: Pass the work_struct pointer instead of context data

2006-11-22T14:55:48+00:00

Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells

WorkStruct: Merge the pending bit into the wq_data pointer

2006-11-22T14:54:49+00:00

Reclaim a word from the size of the work_struct by folding the pending bit and the wq_data pointer together. This shouldn't cause misalignment problems as all pointers should be at least 4-byte aligned. Signed-Off-By: David Howells

WorkStruct: Typedef the work function prototype

2006-11-22T14:54:45+00:00

Define a type for the work function prototype. It's not only kept in the work_struct struct, it's also passed as an argument to several functions. This makes it easier to change it. Signed-Off-By: David Howells

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

[PATCH] Split struct request ->flags into two parts

2006-09-30T18:23:37+00:00

Right now ->flags is a bit of a mess: some are request types, and others are just modifiers. Clean this up by splitting it into ->cmd_type and ->cmd_flags. This allows introduction of generic Linux block message types, useful for sending generic Linux commands to block devices. Signed-off-by: Jens Axboe

[PATCH] exit early in floppy_init when no floppy exists

2006-09-01T18:39:08+00:00

modprobe -v floppy on a Apple G5 writes incorrect stuff to dmesg: Floppy drive(s): fd0 is 2.88M The reason is that the legacy io check happens very late, when part of the floppy stuff is already initialized. check_legacy_ioport() returns either -ENODEV right away, or it walks the device-tree looking for a floppy node. Signed-off-by: Olaf Hering Acked-by: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] lockdep: floppy.c irq release fix

2006-07-03T22:27:00+00:00

The lock validator triggered a number of bugs in the floppy driver, all related to the floppy driver allocating and freeing irq and dma resources from interrupt context. The initial solution was to use schedule_work() to push this into process context, but this caused further problems: for example the current floppy driver in -mm2 is totally broken and all floppy commands time out with an error. (as reported by Barry K. Nathan) This patch tries another solution: simply get rid of all that dynamic IRQ and DMA allocation/freeing. I doubt it made much sense back in the heydays of floppies (if two devices raced for DMA or IRQ resources then we didnt handle those cases too gracefully anyway), and today it makes near zero sense. So the new code does the simplest and most straightforward thing: allocate IRQ and DMA resources at module init time, and free them at module removal time. Dont try to release while the driver is operational. This, besides making the floppy driver functional again has an added bonus, floppy IRQ stats are finally persistent and visible in /proc/interrupts: 6: 63 XT-PIC-level floppy Besides normal floppy IO i have also tested IO error handling, motor-off timeouts, etc. - and everything seems to be working fine. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds