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* splice: implement default splice_read methodMiklos Szeredi2009-05-111-6/+1
| | | | | | | | | | | | If f_op->splice_read() is not implemented, fall back to a plain read. Use vfs_readv() to read into previously allocated pages. This will allow splice and functions using splice, such as the loop device, to work on all filesystems. This includes "direct_io" files in fuse which bypass the page cache. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Make non-compat preadv/pwritev use native register sizeLinus Torvalds2009-04-041-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of always splitting the file offset into 32-bit 'high' and 'low' parts, just split them into the largest natural word-size - which in C terms is 'unsigned long'. This allows 64-bit architectures to avoid the unnecessary 32-bit shifting and masking for native format (while the compat interfaces will obviously always have to do it). This also changes the order of 'high' and 'low' to be "low first". Why? Because when we have it like this, the 64-bit system calls now don't use the "pos_high" argument at all, and it makes more sense for the native system call to simply match the user-mode prototype. This results in a much more natural calling convention, and allows the compiler to generate much more straightforward code. On x86-64, we now generate testq %rcx, %rcx # pos_l js .L122 #, movq %rcx, -48(%rbp) # pos_l, pos from the C source loff_t pos = pos_from_hilo(pos_h, pos_l); ... if (pos < 0) return -EINVAL; and the 'pos_h' register isn't even touched. It used to generate code like mov %r8d, %r8d # pos_low, pos_low salq $32, %rcx #, tmp71 movq %r8, %rax # pos_low, pos.386 orq %rcx, %rax # tmp71, pos.386 js .L122 #, movq %rax, -48(%rbp) # pos.386, pos which isn't _that_ horrible, but it does show how the natural word size is just a more sensible interface (same arguments will hold in the user level glibc wrapper function, of course, so the kernel side is just half of the equation!) Note: in all cases the user code wrapper can again be the same. You can just do #define HALF_BITS (sizeof(unsigned long)*4) __syscall(PWRITEV, fd, iov, count, offset, (offset >> HALF_BITS) >> HALF_BITS); or something like that. That way the user mode wrapper will also be nicely passing in a zero (it won't actually have to do the shifts, the compiler will understand what is going on) for the last argument. And that is a good idea, even if nobody will necessarily ever care: if we ever do move to a 128-bit lloff_t, this particular system call might be left alone. Of course, that will be the least of our worries if we really ever need to care, so this may not be worth really caring about. [ Fixed for lost 'loff_t' cast noticed by Andrew Morton ] Acked-by: Gerd Hoffmann <kraxel@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: Ingo Molnar <mingo@elte.hu> Cc: Ralf Baechle <ralf@linux-mips.org>> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* preadv/pwritev: Add preadv and pwritev system calls.Gerd Hoffmann2009-04-021-0/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds preadv and pwritev system calls. These syscalls are a pretty straightforward combination of pread and readv (same for write). They are quite useful for doing vectored I/O in threaded applications. Using lseek+readv instead opens race windows you'll have to plug with locking. Other systems have such system calls too, for example NetBSD, check here: http://www.daemon-systems.org/man/preadv.2.html The application-visible interface provided by glibc should look like this to be compatible to the existing implementations in the *BSD family: ssize_t preadv(int d, const struct iovec *iov, int iovcnt, off_t offset); ssize_t pwritev(int d, const struct iovec *iov, int iovcnt, off_t offset); This prototype has one problem though: On 32bit archs is the (64bit) offset argument unaligned, which the syscall ABI of several archs doesn't allow to do. At least s390 needs a wrapper in glibc to handle this. As we'll need a wrappers in glibc anyway I've decided to push problem to glibc entriely and use a syscall prototype which works without arch-specific wrappers inside the kernel: The offset argument is explicitly splitted into two 32bit values. The patch sports the actual system call implementation and the windup in the x86 system call tables. Other archs follow as separate patches. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <linux-api@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [CVE-2009-0029] System call wrappers part 20Heiko Carstens2009-01-141-6/+7
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [CVE-2009-0029] System call wrappers part 19Heiko Carstens2009-01-141-4/+4
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [CVE-2009-0029] System call wrappers part 16Heiko Carstens2009-01-141-2/+2
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [CVE-2009-0029] System call wrapper special casesHeiko Carstens2009-01-141-4/+20
| | | | | | | | | | | | System calls with an unsigned long long argument can't be converted with the standard wrappers since that would include a cast to long, which in turn means that we would lose the upper 32 bit on 32 bit architectures. Also semctl can't use the standard wrapper since it has a 'union' parameter. So we handle them as special case and add some extra wrappers instead. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* [CVE-2009-0029] Convert all system calls to return a longHeiko Carstens2009-01-141-9/+9
| | | | | | | | | Convert all system calls to return a long. This should be a NOP since all converted types should have the same size anyway. With the exception of sys_exit_group which returned void. But that doesn't matter since the system call doesn't return. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* vfs: lseek(fd, 0, SEEK_CUR) race conditionAlain Knaff2009-01-051-0/+13
| | | | | | | | | | | | | | | | | | This patch fixes a race condition in lseek. While it is expected that unpredictable behaviour may result while repositioning the offset of a file descriptor concurrently with reading/writing to the same file descriptor, this should not happen when merely *reading* the file descriptor's offset. Unfortunately, the only portable way in Unix to read a file descriptor's offset is lseek(fd, 0, SEEK_CUR); however executing this concurrently with read/write may mess up the position. [with fixes from akpm] Signed-off-by: Alain Knaff <alain@knaff.lu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* [PATCH] generic_file_llseek tidyupsChristoph Hellwig2008-10-231-18/+40
| | | | | | | | Add kerneldoc for generic_file_llseek and generic_file_llseek_unlocked, use sane variable names and unclutter the code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Remove BKL from remote_llseek v2Andi Kleen2008-07-021-27/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Replace remote_llseek with generic_file_llseek_unlocked (to force compilation failures in all users) - Change all users to either use generic_file_llseek_unlocked directly or take the BKL around. I changed the file systems who don't use the BKL for anything (CIFS, GFS) to call it directly. NCPFS and SMBFS and NFS take the BKL, but explicitely in their own source now. I moved them all over in a single patch to avoid unbisectable sections. Open problem: 32bit kernels can corrupt fpos because its modification is not atomic, but they can do that anyways because there's other paths who modify it without BKL. Do we need a special lock for the pos/f_version = 0 checks? Trond says the NFS BKL is likely not needed, but keep it for now until his full audit. v2: Use generic_file_llseek_unlocked instead of remote_llseek_unlocked and factor duplicated code (suggested by hch) Cc: Trond.Myklebust@netapp.com Cc: swhiteho@redhat.com Cc: sfrench@samba.org Cc: vandrove@vc.cvut.cz Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* fs: use loff_t type instead of long longDavid Sterba2008-04-221-3/+3
| | | | | | | Use offset type consistently. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* remove the unused exports of sys_open/sys_readArjan van de Ven2008-02-081-1/+0
| | | | | | | | | | | These exports (which aren't used and which are in fact dangerous to use because they pretty much form a security hole to use) have been marked _UNUSED since 2.6.24 with removal in 2.6.25. This patch is their final departure from the Linux kernel tree. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ext4: export iov_shorten from kernel for ext4's useEric Sandeen2008-01-281-0/+1
| | | | | | | Export iov_shorten() from kernel so that ext4 can truncate too-large writes to bitmapped files. Signed-off-by: Eric Sandeen <sandeen@redhat.com>
* security: call security_file_permission from rw_verify_areaJames Morris2008-01-251-39/+24
| | | | | | | | All instances of rw_verify_area() are followed by a call to security_file_permission(), so just call the latter from the former. Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* mark sys_open/sys_read exports unusedArjan van de Ven2007-11-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | sys_open / sys_read were used in the early 1.2 days to load firmware from disk inside drivers. Since 2.0 or so this was deprecated behavior, but several drivers still were using this. Since a few years we have a request_firmware() API that implements this in a nice, consistent way. Only some old ISA sound drivers (pre-ALSA) still straggled along for some time.... however with commit c2b1239a9f22f19c53543b460b24507d0e21ea0c the last user is now gone. This is a good thing, since using sys_open / sys_read etc for firmware is a very buggy to dangerous thing to do; these operations put an fd in the process file descriptor table.... which then can be tampered with from other threads for example. For those who don't want the firmware loader, filp_open()/vfs_read are the better APIs to use, without this security issue. The patch below marks sys_open and sys_read unused now that they're really not used anymore, and for deletion in the 2.6.25 timeframe. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Cleanup macros for distinguishing mandatory locksPavel Emelyanov2007-10-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | The combination of S_ISGID bit set and S_IXGRP bit unset is used to mark the inode as "mandatory lockable" and there's a macro for this check called MANDATORY_LOCK(inode). However, fs/locks.c and some filesystems still perform the explicit i_mode checking. Besides, Andrew pointed out, that this macro is buggy itself, as it dereferences the inode arg twice. Convert this macro into static inline function and switch its users to it, making the code shorter and more readable. The __mandatory_lock() helper is to be used in places where the IS_MANDLOCK() for superblock is already known to be true. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: David Howells <dhowells@redhat.com> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Remove remnants of sendfile()Jens Axboe2007-07-101-15/+11
| | | | | | | There are now zero users of .sendfile() in the kernel, so kill it from the file_operations structure and in do_sendfile(). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* splice: divorce the splice structure/function definitions from the pipe headerJens Axboe2007-07-101-1/+1
| | | | | | | | | We need to move even more stuff into the header so that folks can use the splice_to_pipe() implementation instead of open-coding a lot of pipe knowledge (see relay implementation), so move to our own header file finally. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* sys_sendfile: switch to using ->splice_read, if availableJens Axboe2007-07-101-4/+20
| | | | | | | This patch makes sendfile prefer to use ->splice_read(), if it's available in the file_operations structure. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* use use SEEK_MAX to validate user lseek argumentsChris Snook2007-05-081-2/+2
| | | | | | | | | Add SEEK_MAX and use it to validate lseek arguments from userspace. Signed-off-by: Chris Snook <csnook@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* use symbolic constants in generic lseek codeChris Snook2007-05-081-6/+6
| | | | | | | | | Convert magic numbers to SEEK_* values from fs.h Signed-off-by: Chris Snook <csnook@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] FS: speed up rw_verify_area()Eric Dumazet2007-02-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | oprofile hunting showed a stall in rw_verify_area(), because of triple indirection and potential cache misses. (file->f_path.dentry->d_inode->i_flock) By moving initialization of 'struct inode' pointer before the pos/count sanity tests, we allow the compiler and processor to perform two loads by anticipation, reducing stall, without prefetch() hints. Even x86 arch has enough registers to not use temporary variables and not increase text size. I validated this patch running a bench and studied oprofile changes, and absolute perf of the test program. Results of my epoll_pipe_bench (source available on request) on a Pentium-M 1.6 GHz machine Before : # ./epoll_pipe_bench -l 30 -t 20 Avg: 436089 evts/sec read_count=8843037 write_count=8843040 21.218390 samples per call (best value out of 10 runs) After : # ./epoll_pipe_bench -l 30 -t 20 Avg: 470980 evts/sec read_count=9549871 write_count=9549894 21.216694 samples per call (best value out of 10 runs) oprofile CPU_CLK_UNHALTED events gave a reduction from 5.3401 % to 2.5851 % for the rw_verify_area() function. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] ifdef ->rchar, ->wchar, ->syscr, ->syscw from task_structAlexey Dobriyan2007-02-111-12/+12
| | | | | | | | | | | | | | | They are fat: 4x8 bytes in task_struct. They are uncoditionally updated in every fork, read, write and sendfile. They are used only if you have some "extended acct fields feature". And please, please, please, read(2) knows about bytes, not characters, why it is called "rchar"? Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jay Lan <jlan@engr.sgi.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] one more EXPORT_UNUSED_SYMBOL removalAdrian Bunk2006-12-131-2/+0
| | | | | | Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] VFS: change struct file to use struct pathJosef "Jeff" Sipek2006-12-081-10/+10
| | | | | | | | | | | | | This patch changes struct file to use struct path instead of having independent pointers to struct dentry and struct vfsmount, and converts all users of f_{dentry,vfsmnt} in fs/ to use f_path.{dentry,mnt}. Additionally, it adds two #define's to make the transition easier for users of the f_dentry and f_vfsmnt. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Add vector AIO supportBadari Pulavarty2006-10-011-54/+75
| | | | | | | | | | | | | | | This work is initially done by Zach Brown to add support for vectored aio. These are the core changes for AIO to support IOCB_CMD_PREADV/IOCB_CMD_PWRITEV. [akpm@osdl.org: huge build fix] Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: Benjamin LaHaise <bcrl@kvack.org> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Streamline generic_file_* interfaces and filemap cleanupsBadari Pulavarty2006-10-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | This patch cleans up generic_file_*_read/write() interfaces. Christoph Hellwig gave me the idea for this clean ups. In a nutshell, all filesystems should set .aio_read/.aio_write methods and use do_sync_read/ do_sync_write() as their .read/.write methods. This allows us to cleanup all variants of generic_file_* routines. Final available interfaces: generic_file_aio_read() - read handler generic_file_aio_write() - write handler generic_file_aio_write_nolock() - no lock write handler __generic_file_aio_write_nolock() - internal worker routine Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Remove readv/writev methods and use aio_read/aio_write insteadBadari Pulavarty2006-10-011-34/+67
| | | | | | | | | | This patch removes readv() and writev() methods and replaces them with aio_read()/aio_write() methods. Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Vectorize aio_read/aio_write fileop methodsBadari Pulavarty2006-10-011-4/+16
| | | | | | | | | | | | This patch vectorizes aio_read() and aio_write() methods to prepare for collapsing all aio & vectored operations into one interface - which is aio_read()/aio_write(). Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Michael Holzheu <HOLZHEU@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fs/read_write.c: EXPORT_UNUSED_SYMBOLAdrian Bunk2006-07-101-1/+1
| | | | | | | | This patch marks an unused export as EXPORT_UNUSED_SYMBOL. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] splice: unlikely() optimizationsJens Axboe2006-04-111-1/+1
| | | | | | | Also corrects a few comments. Patch mainly from Ingo, changes by me. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jens Axboe <axboe@suse.de>
* [PATCH] Make most file operations structs in fs/ constArjan van de Ven2006-03-281-1/+1
| | | | | | | | | | | | | | This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove needless check in fs/read_write.cCarsten Otte2006-03-251-1/+1
| | | | | | | | | nr_segs is unsigned long and thus cannot be negative. We checked against 0 few lines before. Signed-off-by: Carsten Otte <cotte@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_semJes Sorensen2006-01-091-2/+2
| | | | | | | | | | | | | This patch converts the inode semaphore to a mutex. I have tested it on XFS and compiled as much as one can consider on an ia64. Anyway your luck with it might be different. Modified-by: Ingo Molnar <mingo@elte.hu> (finished the conversion) Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Relax the rw_verify_area() error checking.Linus Torvalds2006-01-041-9/+25
| | | | | | | | | | | | | | | In particular, allow over-large read- or write-requests to be downgraded to a more reasonable range, rather than considering them outright errors. We want to protect lower layers from (the sadly all too common) overflow conditions, but prefer to do so by chopping the requests up, rather than just refusing them outright. Cc: Peter Anvin <hpa@zytor.com> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Andi Kleen <ak@suse.de> Cc: Al Viro <viro@ftp.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] readv/writev syscalls are not checked by lsmKostik Belousov2005-09-291-0/+3
| | | | | | | | | | | | | | it seems that readv(2)/writev(2) syscalls do not call file_permission callback. Looks like this is overlook. I have filled the issue into redhat bugzilla as https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=169433 and got the recommendation to post this on lsm mailing list. The following trivial patch solves the problem. Signed-off-by: Kostik Belousov <kostikbel@gmail.com> Signed-off-by: Chris Wright <chrisw@osdl.org>
* [PATCH] remove file.f_maxcountEric Dumazet2005-09-071-1/+1
| | | | | | | | | struct file cleanup: f_maxcount has an unique value (INT_MAX). Just use the hard-wired value. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] inotifyRobert Love2005-07-121-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 system call that returns a fd, not SIGIO. You get a single fd, 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), Gamin (a FAM replacement), and other projects. See Documentation/filesystems/inotify.txt. Signed-off-by: Robert Love <rml@novell.com> Cc: John McCutchan <ttb@tentacle.dhs.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: fix do_sync_(read|write) to properly handle aio retriesBenjamin LaHaise2005-06-231-2/+18
| | | | | | | | | | When do_sync_(read|write) encounters an aio method that makes use of the retry mechanism, they fail to correctly retry the operation. This fixes that by adding the appropriate sleep and retry mechanism. Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] undo do_readv_writev() behavior changeDave Hansen2005-04-161-2/+2
| | | | | | | | | | | Bugme bug 4326: http://bugme.osdl.org/show_bug.cgi?id=4326 reports: executing the systemcall readv with Bad argument ->len == -1) it gives out error EFAULT instead of EINVAL Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+730
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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