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2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-03-07[WATCHDOG] watchdog_info constifyWim Van Sebroeck
make the watchdog_info struct const where possible. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2010-02-27MIPS: AR7: Implement clock APIFlorian Fainelli
This patch makes the ar7 clock code implement the Linux clk API. Drivers using the various clocks available in the SoC are updated accordingly. Signed-off-by: Florian Fainelli <florian@openwrt.org> Acked-by: Wim Van Sebroeck <wim@iguana.be> To: linux-mips@linux-mips.org Cc: Wim Van Sebroeck <wim@iguana.be> Cc: netdev@vger.kernel.org Cc: David Miller <davem@davemloft.net> Patchwork: http://patchwork.linux-mips.org/patch/881/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-09-18[WATCHDOG] ar7_wdt: Fix error handling during probe.Wim Van Sebroeck
Fix error handling in the probe function. Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Tested-by: Florian Fainelli <florian@openwrt.org>
2009-09-18[WATCHDOG] ar7_wdt: convert to become a platform driverFlorian Fainelli
This patch converts the ar7_wdt driver to become a platform driver. The AR7 SoC specific identification and base register calculation is performed by the board code, therefore we no longer need to have access to ar7_chip_id. We also remove the reboot notifier code to use the platform shutdown method as Wim suggested. Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2009-08-15[WATCHDOG] ar7_wdt: fix path to ar7-specific headersFlorian Fainelli
AR7 is currently being resubmitted for mainline inclusion and we changed the path to the ar7-specific headers from ar7 to mach-ar7 to reflect the other MIPS-based boards header hierarchy. This patch will avoid any future compilation failure due to missing headers. Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2009-06-18[WATCHDOG] Correct WDIOF_MAGICCLOSE flagWim Van Sebroeck
Make sure that when the WDIOF_MAGICCLOSE flag is set we also support the magic-close feature... Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-08-06[WATCHDOG] more coding style clean-up'sWim Van Sebroeck
More coding style clean-up's. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-08-06[WATCHDOG] Coding style - Indentation - part 2Wim Van Sebroeck
This brings the watchdog drivers into line with coding style. This patch takes cares of the indentation as described in chapter 1. Main changes: * Re-structure the ioctl switch call for all drivers as follows: switch (cmd) { case WDIOC_GETSUPPORT: case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: case WDIOC_GETTEMP: case WDIOC_SETOPTIONS: case WDIOC_KEEPALIVE: case WDIOC_SETTIMEOUT: case WDIOC_GETTIMEOUT: case WDIOC_GETTIMELEFT: default: } This to make the migration from the drivers to the uniform watchdog device driver easier in the future. Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-08-04ar7_wdt watchdog driver: Fix lockingAlan Cox
Use unlocked_ioctl Remove semaphores Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-25[WATCHDOG] constify function pointer tablesJan Engelhardt
"static struct file_operations" should be "static const struct file_operations". Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2007-10-23[WATCHDOG] AR7: watchdog timerMatteo Croce
Driver for the watchdog timer. Still doesn't reboots the machine on some boards, but we have improved and cleaned it Signed-off-by: Matteo Croce <technoboy85@gmail.com> Signed-off-by: Nicolas Thill <nico@openwrt.org> Signed-off-by: Enrik Berkhan <Enrik.Berkhan@akk.org> Signed-off-by: Christer Weinigel <wingel@nano-system.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>