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path: root/fs/notify/inotify/inotify_user.c
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2012-09-26switch simple cases of fget_light to fdgetAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-04-05inotify: fix double free/corruption of stuct userEric Paris
On an error path in inotify_init1 a normal user can trigger a double free of struct user. This is a regression introduced by a2ae4cc9a16e ("inotify: stop kernel memory leak on file creation failure"). We fix this by making sure that if a group exists the user reference is dropped when the group is cleaned up. We should not explictly drop the reference on error and also drop the reference when the group is cleaned up. The new lifetime rules are that an inotify group lives from inotify_new_group to the last fsnotify_put_group. Since the struct user and inotify_devs are directly tied to this lifetime they are only changed/updated in those two locations. We get rid of all special casing of struct user or user->inotify_devs. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: stable@kernel.org (2.6.37 and up) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-01Remove one to many n's in a wordJustin P. Mattock
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-12-07inotify: stop kernel memory leak on file creation failureEric Paris
If inotify_init is unable to allocate a new file for the new inotify group we leak the new group. This patch drops the reference on the group on file allocation failure. Reported-by: Vegard Nossum <vegard.nossum@gmail.com> cc: stable@kernel.org Signed-off-by: Eric Paris <eparis@redhat.com>
2010-10-28fsnotify: rename FS_IN_ISDIR to FS_ISDIREric Paris
The _IN_ in the naming is reserved for flags only used by inotify. Since I am about to use this flag for fanotify rename it to be generic like the rest. Signed-off-by: Eric Paris <eparis@redhat.com>
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>
2010-07-28fsnotify: remove group->maskEric Paris
group->mask is now useless. It was originally a shortcut for fsnotify to save on performance. These checks are now redundant, so we remove them. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: fsnotify_add_notify_event should return an eventEric Paris
Rather than the horrific void ** argument and such just to pass the fanotify_merge event back to the caller of fsnotify_add_notify_event() have those things return an event if it was different than the event suggusted to be added. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: add pr_debug throughoutEric Paris
It can be hard to debug fsnotify since there are so few printks. Use pr_debug to allow for dynamic debugging. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify: Fix mask checksJerome Marchand
The mask checks in inotify_update_existing_watch() and inotify_new_watch() are useless because inotify_arg_to_mask() sets FS_IN_IGNORED and FS_EVENT_ON_CHILD bits anyway. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify: force inotify and fsnotify use same bitsEric Paris
inotify uses bits called IN_* and fsnotify uses bits called FS_*. These need to line up. This patch adds build time checks to make sure noone can change these bits so they are not the same. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify: allow users to request not to recieve events on unlinked childrenEric Paris
An inotify watch on a directory will send events for children even if those children have been unlinked. This patch add a new inotify flag IN_EXCL_UNLINK which allows a watch to specificy they don't care about unlinked children. This should fix performance problems seen by tasks which add a watch to /tmp and then are overrun with events when other processes are reading and writing to unlinked files they created in /tmp. https://bugzilla.kernel.org/show_bug.cgi?id=16296 Requested-by: Matthias Clasen <mclasen@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify: send IN_UNMOUNT eventsEric Paris
Since the .31 or so notify rewrite inotify has not sent events about inodes which are unmounted. This patch restores those events. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify_user.c: make local symbol staticH Hartley Sweeten
The symbol inotify_max_user_watches is not used outside this file and should be static. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: intoduce a notification merge argumentEric Paris
Each group can define their own notification (and secondary_q) merge function. Inotify does tail drop, fanotify does matching and drop which can actually allocate a completely new event. But for fanotify to properly deal with permissions events it needs to know the new event which was ultimately added to the notification queue. This patch just implements a void ** argument which is passed to the merge function. fanotify can use this field to pass the new event back to higher layers. Signed-off-by: Eric Paris <eparis@redhat.com> for fanotify to properly deal with permissions events
2010-07-28fsnotify: allow marks to not pin inodes in coreEric Paris
inotify marks must pin inodes in core. dnotify doesn't technically need to since they are closed when the directory is closed. fanotify also need to pin inodes in core as it works today. But the next step is to introduce the concept of 'ignored masks' which is actually a mask of events for an inode of no interest. I claim that these should be liberally sent to the kernel and should not pin the inode in core. If the inode is brought back in the listener will get an event it may have thought excluded, but this is not a serious situation and one any listener should deal with. This patch lays the ground work for non-pinning inode marks by using lazy inode pinning. We do not pin a mark until it has a non-zero mask entry. If a listener new sets a mask we never pin the inode. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: split generic and inode specific mark codeEric Paris
currently all marking is done by functions in inode-mark.c. Some of this is pretty generic and should be instead done in a generic function and we should only put the inode specific code in inode-mark.c Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: take inode->i_lock inside fsnotify_find_mark_entry()Andreas Gruenbacher
All callers to fsnotify_find_mark_entry() except one take and release inode->i_lock around the call. Take the lock inside fsnotify_find_mark_entry() instead. Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify: rename mark_entry to just markEric Paris
rename anything in inotify that deals with mark_entry to just be mark. It makes a lot more sense. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: rename fsnotify_find_mark_entry to fsnotify_find_markEric Paris
the _entry portion of fsnotify functions is useless. Drop it. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: rename fsnotify_mark_entry to just fsnotify_markEric Paris
The name is long and it serves no real purpose. So rename fsnotify_mark_entry to just fsnotify_mark. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: put inode specific fields in an fsnotify_mark in a unionEric Paris
The addition of marks on vfs mounts will be simplified if the inode specific parts of a mark and the vfsmnt specific parts of a mark are actually in a union so naming can be easy. This patch just implements the inode struct and the union. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: drop mask argument from fsnotify_alloc_groupEric Paris
Nothing uses the mask argument to fsnotify_alloc_group. This patch drops that argument. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: fsnotify_obtain_group should be fsnotify_alloc_groupEric Paris
fsnotify_obtain_group was intended to be able to find an already existing group. Nothing uses that functionality. This just renames it to fsnotify_alloc_group so it is clear what it is doing. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: remove group_num altogetherEric Paris
The original fsnotify interface has a group-num which was intended to be able to find a group after it was added. I no longer think this is a necessary thing to do and so we remove the group_num. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: per group notification queue merge typesEric Paris
inotify only wishes to merge a new event with the last event on the notification fifo. fanotify is willing to merge any events including by means of bitwise OR masks of multiple events together. This patch moves the inotify event merging logic out of the generic fsnotify notification.c and into the inotify code. This allows each use of fsnotify to provide their own merge functionality. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify: do not spam console without limitEric Paris
inotify was supposed to have a dmesg printk ratelimitor which would cause inotify to only emit one message per boot. The static bool was never set so it kept firing messages. This patch correctly limits warnings in multiple places. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify: do not reuse watch descriptorsEric Paris
Prior to 2.6.31 inotify would not reuse watch descriptors until all of them had been used at least once. After the rewrite inotify would reuse watch descriptors. The selinux utility 'restorecond' was found to have problems when watch descriptors were reused. This patch reverts to the pre inotify rewrite behavior to not reuse watch descriptors. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify: use container_of instead of castingEric Paris
inotify_free_mark casts directly from an fsnotify_mark_entry to an inotify_inode_mark_entry. This works, but should use container_of instead for future proofing. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28fsnotify: allow addition of duplicate fsnotify marksEric Paris
This patch allows a task to add a second fsnotify mark to an inode for the same group. This mark will be added to the end of the inode's list and this will never be found by the stand fsnotify_find_mark() function. This is useful if a user wants to add a new mark before removing the old one. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28inotify: simplify the inotify idr handlingEric Paris
This patch moves all of the idr editing operations into their own idr functions. It makes it easier to prove locking correctness and to to understand the code flow. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-05-14inotify: race use after free/double free in inotify inode marksEric Paris
There is a race in the inotify add/rm watch code. A task can find and remove a mark which doesn't have all of it's references. This can result in a use after free/double free situation. Task A Task B ------------ ----------- inotify_new_watch() allocate a mark (refcnt == 1) add it to the idr inotify_rm_watch() inotify_remove_from_idr() fsnotify_put_mark() refcnt hits 0, free take reference because we are on idr [at this point it is a use after free] [time goes on] refcnt may hit 0 again, double free The fix is to take the reference BEFORE the object can be found in the idr. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: <stable@kernel.org>
2010-05-14inotify: clean up the inotify_add_watch out pathEric Paris
inotify_add_watch explictly frees the unused inode mark, but it can just use the generic code. Just do that. Signed-off-by: Eric Paris <eparis@redhat.com>
2010-02-19switch inotify_user to anon_inodeAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-15inotify: do not reuse watch descriptorsEric Paris
Since commit 7e790dd5fc937bc8d2400c30a05e32a9e9eef276 ("inotify: fix error paths in inotify_update_watch") inotify changed the manor in which it gave watch descriptors back to userspace. Previous to this commit inotify acted like the following: inotify_add_watch(X, Y, Z) = 1 inotify_rm_watch(X, 1); inotify_add_watch(X, Y, Z) = 2 but after this patch inotify would return watch descriptors like so: inotify_add_watch(X, Y, Z) = 1 inotify_rm_watch(X, 1); inotify_add_watch(X, Y, Z) = 1 which I saw as equivalent to opening an fd where open(file) = 1; close(1); open(file) = 1; seemed perfectly reasonable. The issue is that quite a bit of userspace apparently relies on the behavior in which watch descriptors will not be quickly reused. KDE relies on it, I know some selinux packages rely on it, and I have heard complaints from other random sources such as debian bug 558981. Although the man page implies what we do is ok, we broke userspace so this patch almost reverts us to the old behavior. It is still slightly racey and I have patches that would fix that, but they are rather large and this will fix it for all real world cases. The race is as follows: - task1 creates a watch and blocks in idr_new_watch() before it updates the hint. - task2 creates a watch and updates the hint. - task1 updates the hint with it's older wd - task removes the watch created by task2 - task adds a new watch and will reuse the wd originally given to task2 it requires moving some locking around the hint (last_wd) but this should solve it for the real world and be -stable safe. As a side effect this patch papers over a bug in the lib/idr code which is causing a large number WARN's to pop on people's system and many reports in kerneloops.org. I'm working on the root cause of that idr bug seperately but this should make inotify immune to that issue. Signed-off-by: Eric Paris <eparis@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16switch alloc_file() to passing struct pathAl Viro
... and have the caller grab both mnt and dentry; kill leak in infiniband, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16switched inotify_init1() to alloc_file()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-09Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits) tree-wide: fix misspelling of "definition" in comments reiserfs: fix misspelling of "journaled" doc: Fix a typo in slub.txt. inotify: remove superfluous return code check hdlc: spelling fix in find_pvc() comment doc: fix regulator docs cut-and-pasteism mtd: Fix comment in Kconfig doc: Fix IRQ chip docs tree-wide: fix assorted typos all over the place drivers/ata/libata-sff.c: comment spelling fixes fix typos/grammos in Documentation/edac.txt sysctl: add missing comments fs/debugfs/inode.c: fix comment typos sgivwfb: Make use of ARRAY_SIZE. sky2: fix sky2_link_down copy/paste comment error tree-wide: fix typos "couter" -> "counter" tree-wide: fix typos "offest" -> "offset" fix kerneldoc for set_irq_msi() spidev: fix double "of of" in comment comment typo fix: sybsystem -> subsystem ...
2009-12-04inotify: remove superfluous return code checkGiuseppe Scrivano
Signed-off-by: Giuseppe Scrivano <gscrivano@gnu.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-18sysctl: Drop & in front of every proc_handler.Eric W. Biederman
For consistency drop & in front of every proc_handler. Explicity taking the address is unnecessary and it prevents optimizations like stubbing the proc_handlers to NULL. Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Joe Perches <joe@perches.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-12sysctl fs: Remove dead binary sysctl supportEric W. Biederman
Now that sys_sysctl is a generic wrapper around /proc/sys .ctl_name and .strategy members of sysctl tables are dead code. Remove them. Cc: Jan Harkes <jaharkes@cs.cmu.edu> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-08-28inotify: update the group mask on mark additionEric Paris
Seperating the addition and update of marks in inotify resulted in a regression in that inotify never gets events. The inotify group mask is always 0. This mask should be updated any time a new mark is added. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-28inotify: fix length reporting and size checkingEric Paris
0db501bd0610ee0c0 introduced a regresion in that it now sends a nul terminator but the length accounting when checking for space or reporting to userspace did not take this into account. This corrects all of the rounding logic. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-28inotify: do not send a block of zeros when no pathname is availableBrian Rogers
When an event has no pathname, there's no need to pad it with a null byte and therefore generate an inotify_event sized block of zeros. This fixes a regression introduced by commit 0db501bd0610ee0c0aca84d927f90bcccd09e2bd where my system wouldn't finish booting because some process was being confused by this. Signed-off-by: Brian Rogers <brian@xyzw.org> Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-27inotify: Ensure we alwasy write the terminating NULL.Eric W. Biederman
Before the rewrite copy_event_to_user always wrote a terqminating '\0' byte to user space after the filename. Since the rewrite that terminating byte was skipped if your filename is exactly a multiple of event_size. Ouch! So add one byte to name_size before we round up and use clear_user to set userspace to zero like /dev/zero does instead of copying the strange nul_inotify_event. I can't quite convince myself len_to_zero will never exceed 16 and even if it doesn't clear_user should be more efficient and a more accurate reflection of what the code is trying to do. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-27inotify: fix locking around inotify watching in the idrEric Paris
The are races around the idr storage of inotify watches. It's possible that a watch could be found from sys_inotify_rm_watch() in the idr, but it could be removed from the idr before that code does it's removal. Move the locking and the refcnt'ing so that these have to happen atomically. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-27inotify: seperate new watch creation updating existing watchesEric Paris
There is nothing known wrong with the inotify watch addition/modification but this patch seperates the two code paths to make them each easy to verify as correct. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-08-17inotify: start watch descriptor count at 1Eric Paris
The inotify_add_watch man page specifies that inotify_add_watch() will return a non-negative integer. However, historically the inotify watches started at 1, not at 0. Turns out that the inotifywait program provided by the inotify-tools package doesn't properly handle a 0 watch descriptor. In 7e790dd5 we changed from starting at 1 to starting at 0. This patch starts at 1, just like in previous kernels, but also just like in previous kernels it's possible for it to wrap back to 0. This preserves the kernel functionality exactly like it was before the patch (neither method broke the spec) Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-17notify: unused event private raceEric Paris
inotify decides if private data it passed to get added to an event was used by checking list_empty(). But it's possible that the event may have been dequeued and the private event removed so it would look empty. The fix is to use the return code from fsnotify_add_notify_event rather than looking at the list. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-21inotify: use GFP_NOFS under potential memory pressureEric Paris
inotify can have a watchs removed under filesystem reclaim. ================================= [ INFO: inconsistent lock state ] 2.6.31-rc2 #16 --------------------------------- inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage. khubd/217 [HC0[0]:SC0[0]:HE1:SE1] takes: (iprune_mutex){+.+.?.}, at: [<c10ba899>] invalidate_inodes+0x20/0xe3 {IN-RECLAIM_FS-W} state was registered at: [<c10536ab>] __lock_acquire+0x2c9/0xac4 [<c1053f45>] lock_acquire+0x9f/0xc2 [<c1308872>] __mutex_lock_common+0x2d/0x323 [<c1308c00>] mutex_lock_nested+0x2e/0x36 [<c10ba6ff>] shrink_icache_memory+0x38/0x1b2 [<c108bfb6>] shrink_slab+0xe2/0x13c [<c108c3e1>] kswapd+0x3d1/0x55d [<c10449b5>] kthread+0x66/0x6b [<c1003fdf>] kernel_thread_helper+0x7/0x10 [<ffffffff>] 0xffffffff Two things are needed to fix this. First we need a method to tell fsnotify_create_event() to use GFP_NOFS and second we need to stop using one global IN_IGNORED event and allocate them one at a time. This solves current issues with multiple IN_IGNORED on a queue having tail drop problems and simplifies the allocations since we don't have to worry about two tasks opperating on the IGNORED event concurrently. Signed-off-by: Eric Paris <eparis@redhat.com>